Successful businesses, Jens, don’t market defective products that kill people and then go belly up, leaving depositors holding the bag.
Well, thats incorrect as well. Here is what I already posted to that allegation here some time ago...
Also the complete Mini-500 accident analysis which shows that no one was killed in a Mini-500 that was due to a poor flight characteristic or part failure that was installed and maintained correctly;
US Aviators Mini-500 Flight Report
06-20-2008, 11:24 PM
Well Scott, then you don't read my posts very well, if that's what you think, so let me set you straight on the subject so that you don't have to post inaccurate and misleading stuff like you just did.
Sure I made mistakes, and I have said so many times. Did my company go out of business because I did something wrong? No. My best dealer tried to run me out of business so he could take over my company, plain and simple. He even ran ad's in KitPlanes magazine looking to hire people when he took it over. It's a fact, ask KitPlanes. You can see by the survey I posted above that a very high percentage of Mini-500 owners were very satisfied with the aircraft, and how I ran my business.
I fought a negative publicity campaign against him for two years, while he successfully stopped my sales. In the aircraft business you don't need fire, smoke will do to keep people away. But even to the end, I stayed in the company trying to find someone to take it over, even for free, just for the sake of the owners and so that the Two-Place helicopter could be completed and people that paid receive them. I took ALL of my own money and put it back into the company for the last months to keep possession of the property for the hopes of finding someone to take it over. I lost everything, when I could just have walked away and kept all the money I earned through a paycheck, and for selling my home and properties. Yes, all went into the company to try and survive the last months, even against the advice of others. That, was foolish, but I don't like being defeat.
When the SBA found out that we had been sending back deposits people paid for the Two-Place, they took over the building the next day, and locked me out of the factory. From then on the checking account was theirs, not mine, and they decided not to give back any more money, not me.
I did not loose my company because it was run badly, in fact, I congratulate all my employees for making it stay open for as long as it did, and all the personal sacrifices they made to keep "our" dream alive. I did everything I could do that was humanly possible to take care of my customers by finding someone that would just pay off the SBA and take over the company, and I would work for them as an employee, but Fred did his job well, and no one would commit in fear of further negative publicity from Fred and Campbell.
In fact, I was defeated by a foo that fought and lied as dirty as they could get, while I had to make sure that everything I said in defense was 100% accurate and provable, because if I would have stretched the facts even a little, they would have used it to eat me alive. Yes, I was defeated and expelled, fighting and kicking at the closed and locked door, not running and hiding with my tail stuck between my legs. I lost everything trying to protect my customers.
So Scott, now that you know the facts, you don't have to repeat the inaccurate story and opinions you gave here today. You now have the opportunity to tell it the way it happened, told to you by the guy it happened to, and not by someone that heard it from someone, and you don't have to be one of the people responsible for spreading these vicious roomers any longer.
As I said before, the one biggest mistake I regret more than anything in my life, was when I stopped paying Captain Zoom for advertising. That was my big mistake. I could have won the war if Zoom would have not been bought by the other side. He may be a back-stabbing Internet assassin and crazy as a bed-bug, but if you pay him, he remains loyal, I got to say that for him.
Mini-500 Accident Analysis
1995-1998
RHCI has always had a policy of not including the tail rotor gearbox with the shipment of a Mini-500 helicopter to anyone who is not a helicopter pilot. This policy has been strictly enforced throughout the years in order to prevent customers who have not yet received proper helicopter training from injuring themselves and the reputation of the Mini-500. Unfortunately, it is impossible to enforce policies for those few who will find a way around them. Several of the pilots involved in a Mini-500 accident were not helicopter pilots at the time their aircraft was shipped from the factory. They received the tail rotor gear box because either they told RHCI they were buying the kit with another person who was a helicopter pilot, or they were somehow able to provide documents to RHCI showing that they were qualified to fly the kit.
In this detailed analysis, it can be seen that all accidents are a result of pilot error or a maintenance/assembly problem aggravated by pilot error, and that the majority occurred to pilots with accumulated low time in helicopters (100 hours or less).
Mini-500 Pilots’ Flight Experience
(Chart removed)
As shown in the chart above, 72% of the helicopter pilots involved in Mini-500 accidents were either low-time helicopter pilots or did not hold a helicopter rating at the time of the accident.
The Mini-500 has become the most popular helicopter in the world since its introduction in 1990 and, like any other helicopter, has been exposed to accidents. It was introduced at a time when the industry needed an economical helicopter not only to purchase, but to operate and maintain as well. New or low-time pilots were attracted to the Mini-500 as a way to enter the rotorcraft field or to build flight hours. The relatively low acquisition cost allowed a new generation of pilots to fulfill their dream of owning and flying a helicopter. High operating costs had previously kept personal flying to a minimum. The Mini-500 created new pilots because it gave them a reason to become helicopter certified, but this did not come without some problems.
The first few years proved to be the most difficult as the Mini-500 was built and "field operated" by the pilots. As expected with any new aircraft, a few mechanical problems occurred as the Mini-500 built up flight hours. Components were re-engineered and retested before being retrofitted to aircraft in the field. One by one these problems were resolved.
The aircraft was introduced with the Rotax 582, a two-cylinder, water-cooled engine, which is considered to be very reliable if properly installed and maintained. The homebuilt industry finally had an inexpensive helicopter that would make many people’s dreams of reliable vertical flight come true. A "state-of-the-art" homebuilt helicopter had achieved a record for affordability and reliability unmatched in the homebuilt industry.
Conversations with Mini-500 pilots from other countries reveal that many of them feel that the U.S. suffers from a severe lack of flying discipline. There are fewer regulations in the U.S. than in most other countries. The U.S. is still the world leader in the aviation industry, and more regulations will not solve some of the problems. The only solution now is "self-regulation.” Flight instructors must demonstrate through their own actions that safety awareness must be applied to flying helicopters. This may explain why the Mini-500 has fewer foreign accidents than U.S. accidents.
A review of the Mini-500 NTSB accident briefs clearly demonstrates that lack of proper training is the primary cause of accidents through entering low rotor RPM conditions, followed by improper or inadequate assembly and maintenance. These are by far the most preventable accidents and require intensive training in avoidance and prevention techniques as well as pilot judgment training. An analysis of the Mini-500 accidents reveals that more pilot training is needed in anticipating power changes, rotor RPM management, and keeping the dual engine/rotor RPM tach in the VFR scan. The Power Enhancement Package (PEP) introduced by RHCI improves the recovery of low rotor RPM, and therefore, RHCI recommends that every Mini-500 owner install it in their aircraft.
Most experienced flight instructors agree that low rotor RPM problems are a result of rapid over pitching of the collective, causing an RPM drop. This is similar to any powered helicopter rotor RPM droop, but the throttle in the Mini-500 will respond immediately if the pilot properly anticipates the need of increasing power before adding collective. Pilots must obtain training in a similar helicopter without relying on the correlator or governor before attempting to fly the Mini-500.
Mini-500 Accident Review
(NTSB Data and Unreported Accidents)
(Chart removed)
Pilot Error 24
Maintenance/Pilot Error 19
Undetermined/Pilot Error 1
TOTAL ACCIDENTS 44
Notes
1. All information was obtained from the NTSB and/or directly from the pilots, witnesses, friends, instructors, customers’ file, etc.
2. Most of these accidents were caused by several related factors and probable causes may tend to be misleading (i.e. a roll-over may be caused by excessive slope or unsuitable terrain, failure to successfully autorotate, improper maintenance and assembly, collision with ground object, etc.).
3. Mechanical failures are often caused by improper assembly, maintenance procedures or exceeding limitations. All of them appear to be attributed to this. In many cases, the pilot misinterpreted or reacted improperly to a minor problem in flight.
4. Most of the accidents were attributed to pilots entering into a low rotor RPM condition and not recovering properly.
5. Approximately 87% of accidents due to autorotative landings appear to be caused by not recovering properly from low rotor RPM conditions. In some cases the pilot reported an engine failure during power recovery on a practice autorotation, or reported a rough engine followed by failure when power was reduced for a landing. Post-accident engine run up found wrong jets installed or in some cases no mechanical problems.
ALL OF THESE ACCIDENTS WERE AVOIDABLE!
Types of Accident
(Chart removed)
Types of Accidents Number of Accidents
A. Maintenance/Pilot Error 19
B. Low Rotor RPM 18
C. Collision With Ground Object 3
D. Fuel Exhaustion 2
E. Power Line Strike 1
F. Undetermined/Pilot Error 1
TOTAL 44
Accident Definitions
A. Maintenance/Pilot Error
Aircraft system failure caused by improper assembly, installation, and/or maintenance procedures (i.e. wrong jets, belt alignment, improper installation of components, loose parts, wrong adhesive, bad fuel, etc.) followed by pilot error (i.e. not successfully autorotating or recovering power after an emergency).
B. Low Rotor RPM
Inadequate control of aircraft, low rotor RPM due to practicing autorotations, pilot operating behind the "power curve,” lack of training, failure to maintain or recover from low rotor, etc.
C. Collision with Ground Objects
Collision during ground run-up or while in hovering flight (i.e. aircraft tie downs, skids caught in a mound of protruding grass, etc.).
D. Fuel Exhaustion
Improper pre-flight preparation, fuel exhaustion due to running out of fuel, leaking, or fuel restriction.
E. Power Line Strike
Collision with a power line while in cruise, takeoff, landing, etc.
F. Undetermined
The NTSB or RHCI has not determined a probable cause of the accident (information unreliable, no eye-witnesses, information not obtainable to determine cause).
RHCI has investigated every known Mini-500 accident, but the investigations alone will accomplish nothing if recommendations aren’t issued and adopted to prevent recurrence. Therefore, the following Mini-500 accident analysis will take a detailed look at how some of the accidents happened and how a typical safety awareness program can prevent most of these accidents:
A. Maintenance - Of the 19 accidents in this category, approximately 98% appear to have occurred as a result of engine failure due to having the wrong jets installed, unauthorized modifications, improper assembly and maintenance procedures. Most reported engine failures appear to have resulted from improper installation and adjustments of the jets. If the proper needle jet and needle position are not installed according to RHCI’s instructions, Airworthiness Directives (AD’s) and advisories, the engine will seize. This would most likely happen in a decent where the improper needle jet arrangement tends to lean the mixture the most.
One accident was caused by installing a type of adhesive on the fuel tank that was not the recommended one, causing the fuel filter to become plugged. In several instances, the pilot or builder forgot to tighten a part (i.e. a jam nut that secures the tail rotor push pull cable left loose after trailering the aircraft; a loose hose clamp caused the engine to lose coolant, and therefore overheat; the collective friction was not tightened and the aircraft was left unattended causing it to take off by itself; etc.). Lack of proper assembly procedures (i.e. drive belt not properly aligned; improper installation of the collective control tube; failure to remove packing material from inside the tail boom after trailering; forgetting to change the center of gravity of the aircraft after a much heavier pilot finished flying; etc.) has caused several of the accidents. In one instance, RHCI suspected that the builder reused the nuts and bolts located in the control system area, because if he would have not done so, the certified bolts and nuts would have not come loose.
When servicing and performing maintenance work in the Mini-500, it is important to pay attention to detail and to make sure that no extra parts are left inside any of the components. Compliance with RHCI’s assembly manual, pilots operating handbook, service bulletins, AD’s, safety notices and RHCI’s newsletters will help eliminate most, if not all, maintenance problems on the Mini-500.
B. Low Rotor RPM - This has always been one of the most common types of helicopter accidents and is quite often listed by the NTSB as a contributing cause of a helicopter accident. It typically occurs to an inexperienced pilot as a result of poor training or judgment and happens to high-time pilots as a result of overconfidence in their ability. Sometimes it occurs as a result of operating behind the power curve, over pitching the collective, twisting the throttle the wrong direction or exceeding the performance limits of the aircraft (i.e. operating at high gross weight, attempting takeoff with high density altitude, etc.). Mini-500 pilots must be made aware of the limits of the aircraft’s correlator system.
If the pilot over pitches the collective without anticipating throttle, a rapid decay will occur that can not be corrected without sufficient airspeed or altitude. Usually the helicopter will settle rapidly to the ground before the pilot can regain control of the RPM. This will occur when landing with a tail wind, allowing rate of descent to build on approach (especially below 100' AGL), landing at a high density altitude site, operating at high gross weights, etc. It can generally be avoided by using a high-speed shallow approach at higher density altitude airports and aborting a takeoff if the aircraft will not hover momentarily (at least a few inches above the surface). Student pilots must be taught procedures for safe operation when flying at other than standard atmospheric conditions.
Autorotations should be practiced frequently, with recovery made before touchdown, until pilots’ skills are developed. New pilots, low time pilots, and pilots not accustomed to flying light weight reciprocating helicopters should not be allowed to practice autorotations in the Mini-500 until they can do so proficiently in a similar two-place helicopter with an instructor. These same pilots should also let experienced pilots first fly their Mini-500, and make all trimming and balancing adjustments. This will make the Mini-500 safer for a new pilot to fly.
Of the 18 accidents in this category, most appear to have been caused because the pilot put himself in a situation where he was not able to recover from low rotor RPM (i.e. operating behind the power curve, experiencing settling with power from 20 ft. or higher, etc.). The most serious accidents have occurred as a result of practicing autorotations when the pilot lacked thorough and recent training and experience in helicopters. Intensive training in low rotor RPM recovery is necessary in a similar type helicopter to reduce this type of accident.
C. Collision With Ground Objects - Three accidents have occurred in the Mini-500 as a result of operating in close proximity to objects on the ground. Most of these accidents occurred when hovering too close to the ground. One pilot was practicing slide on landings from a hover, and the skids caught on an aircraft tie down. On another occasion, a pilot thought he could fly his aircraft out of his garage. While attempting to do this, the down wash pulled the door down on top of the rotors. Another pilot while hovering the helicopter for the first time, to break in the engine, drifted off the tarmac area onto a grassy area, causing one skid to get caught in a mound of grass.
RHCI has found that the odds of striking an object on the ground are much greater than a hard landing due to engine failure, because of the Mini-500’s high inertia system. An altitude of at least 12 inches will avoid most objects on the ground.
Landing in unknown or unfavorable sites is generally a contributing factor in this type of accident. Quite often the pilot has not seen the object until it is too late, thereby colliding with it or losing control trying to avoid it. Other times the pilot will land on a severe slope, tall grass or soft terrain and the aircraft will roll-over. Ground instruction on the types of terrain that are unsuitable for skid-type landing gear must be given to students by flight instructors. Instructors must use self-control when teaching new students. Demonstrating landings in extremely hazardous areas has little training value when teaching pilot judgment.
D. Fuel Exhaustion - There were two reports of accidents caused by fuel exhaustion in the Mini-500. In one instance, the pilot failed to pre-flight the aircraft for fuel level before taking off, causing it to run out of fuel while in flight. On another occasion, RHCI suspected that the pilot filled his gas tank with low octane level (less than 87 octane) without knowing it, causing the engine to fail due to pre-detonation. It was reported to RHCI that the aircraft was freshly refueled at the airport gas pump, and based on RHCI’s past experiences, the grade usually offered by airports in auto gas is less than 87 octane. If the gas is in the ground for a long period of time, it will lose octane, and low octane gas will pre-detonate in the Rotax engine, as explained in the Rotax manual. RHCI recommends that pilots always test the fuel for octane level when obtaining fuel from an airport or even from the local gas station.
E. Power Line Strike - Even though there was only one accident caused directly by a Mini-500 striking a power line, two other accidents can also be attributed to power lines. One pilot flew into a power line at 70 MPH while flight testing for forward balance. The power line contacted the aircraft on the mast, and the pilot was able to maintain control up until ground contact. On another two occasions, the pilots failed to see the power lines before taking off, but were able to miss them. In the process, they allowed the rotor RPM to droop and were unable to recover.
Contrary to popular belief, most wire strikes occur in clear weather conditions. This type of wire encounter is most likely to be fatal since the aircraft is usually operating at a high rate of speed at the moment of impact. Intensive ground training on wire strike avoidance is required to avoid this common fatal accident. Only experienced pilots should fly low level operations.
G. Undetermined/Pilot Error - Only 1 accident in the Mini-500 has been undetermined during this period. The pilot did not successfully complete an autorotation and did not have the engine disassembled to determine the reason for failure. Therefore, engine failure is undetermined.
The Revolution Mini-500 makes up approximately 4% of the total U.S. civil helicopter fleet (year end 1998). There are approximately 436 Mini-500 helicopters in the U.S. compared to 10,892 other types of helicopters. Of the 436 Mini-500’s in the U.S. fleet, 38 were involved in accidents for the calendar years 1995-1998, or approximately .35% of the U.S. fleet. Of the 10,892 other helicopters, 716 were involved in accidents during this same period, or approximately 6.5% of the U.S. fleet. This includes helicopters used for such diverse operations as crop dusting, corporate, off-shore, personal and business, EMS, etc.
Considering the role the Mini-500 has in the worldwide personal use market, the Mini-500 would be expected to have a proportionately higher number of accidents each year. Enstrom had similar problems back in the 1970's when F. Lee Bailey spiffed up the F28A and targeted the businessman market. The accident rate soared as dealers sold executives the idea of the modern “flying carpet.” Unfortunately, despite claims made as early as 1950, the world is still not ready for a helicopter in everyone's garage. Even the MD-500, one of the easiest light helicopters to fly, can be a handful to an inexperienced pilot, a phenomenon that is not unlike the V-Tail Beech or the Cessna Citation. Considering the fact that Mini-500 helicopters are used for some type of personal recreation (which generally involves numerous takeoffs/landings), the accident rate per aircraft flying becomes even more favorable.
To take this analysis a little further, let's look at the total transportation accidents records in the U.S. as published annually by the NTSB:
Comparison of U.S. Transportation Fatalities for 1997
Fatalities Fatalities
Passenger Cars 22,227 Pedacycles 800
Trains 746 Airplanes (G.A.) 646
Buses 15 Helicopters 78
Motorcycles 2,099 (Mini-500) 3
During 1998, total helicopter fatalities were 91, while the Mini-500 only had 4.
A detailed analysis would be necessary in order to assess risk/benefit in any form of transportation. How often has it been said in the helicopter industry (since Igor Sikorsky first said it) that a helicopter is potentially one of the safest forms of transportation? This statement may very well prove to be true someday.
Mini-500 Total Accidents
(Chart removed)
Out of 44 flight related Mini-500 accidents, there were 35 accidents with minor or no injuries (80%), 2 serious injuries (4%), and 7 fatal (16%). Of the nine serious and fatal accidents, five were caused by pilot error and four by maintenance aggravated by pilot error.
Mini-500 Accident Rate vs. Total Aircraft Flying
(Chart removed)
RHCI estimates that about 400 out of 521 Mini-500 sold are flying or capable of flight. RHCI bases this estimate on conversations and letters received from the builders. This indicates that 44 (11%) out of an estimated 400 flyable Mini-500s were involved in an accident.
Conclusion
The results of accident investigations or safety studies are useless unless the information is readily available to those who need it. Pilots are still cited as a cause or contributing factor in about 85% of all general aviation accidents. While new technology and design have clearly played an important role in the improved safety record, the potential for continued improvements down the road may be diminishing and we need to focus on the human factors affecting the safety of flight operations: factors such as situational awareness, error chain detection and analysis, communication skills, decision-making, stress management, etc.
This Mini-500 Accident Analysis has been compiled in the interest of helicopter safety and can be adapted to any type of helicopter safety program. Flight schools and instructors are urged to review these and other Mini-500 accident data with students to make them aware of some common mistakes made by Mini-500 pilots. All helicopter pilots are aware of the inherent risks involved in aviation, especially the unique risk to helicopter operations. Any type of flying activity involves certain risk, whether it be in an ultralight airplane or a commercial airliner, and pilots have accepted the risk realizing full well the consequences when something goes wrong.
Despite repeated criticism from opponents, the Mini-500 helicopter has proven itself to be one of the safest helicopters ever manufactured. It was certified as a homebuilt kit under the 51% category. Its primary markets (personal training for adding on hours and personal use) have placed it in a high risk category and not unlike the Cessna 152, it is exposed to a higher accidents rate.
The Mini-500 and the pilots that fly it throughout the world have achieved a remarkable record in helicopter safety. It has given many the opportunity to finally own a helicopter, and it has helped many pilots to increase their helicopter flight time inexpensively. It has opened the market and allowed pilots all over the world to learn to fly helicopters affordably. A Mini-500 as well as any other helicopter will crash as a result of low rotor RPM or poor maintenance. These types of accidents may very likely occur in a helicopter other than the Mini-500, but that would probably not receive the same level of attention as a Mini-500 accident.
Many pilots who have been flying the Mini-500 are aware of some of the more controversial accidents in the past few years. Many of us in the industry are aware of these accidents, but it is rare that the actual circumstances are revealed. NTSB data tends to indicate the probability that the accident was caused by pilot error. RHCI has acted responsibly, as it always has in the past, to prevent future accidents. I am comfortable knowing that with good training and supervision, people are probably safer in the aircraft than in the car.
NOTES: All data and statistics have been obtained from NTSB and the Helicopter Association International (HAI) sources.
Mini-500 Reported Accidents to the NTSB
The following accident summaries are abstracts from NTSB Accident Reports and are intended to keep operators, maintenance personnel and safety managers aware of the Mini-500 helicopter safety trends. Except for RHCI Investigative Findings, the text of these reports is taken from NTSB reports; no editorializing has been done.
Followng each NTSB accident report, RHCI includes its findings (RHCI Investigative Findings) after investigating each accident and obtaining information from the NTSB, FAA, pilots, witnesses, and RHCI’s customers’ file. It is RHCI’s intent to clarify the information and help those seeking the real cause of the accidents to understand what could go wrong when flying not only the Mini-500, but any helicopter. The RHCI information is the opinion of RHCI, and should not necessarily reflect the opinion of the NTSB, FAA or any other affiliated group or organization.
(1) NTSB Identification: CHI95FA242
Accident occurred Jul-27-95 At Oshkosh, WI
Aircraft: Revolution Helicopter Mini-500, registration: N500ZZ
Injuries: 1 Uninjured
The amateur-built helicopter was conducting a demonstration flight during the annual EAA convention. During the first flight after re-jetting of the carburetor, the helicopter experienced a total loss of engine power. During the autorotation into a crop field, the helicopter was substantially damaged when the skid shoes caught in the terrain, failing the left skid and fracturing the shoe on that skid. Subsequent examination of the engine revealed that the rear piston had seized in the cylinder. The owner of the company which produces the helicopter stated that the re-jetting of the carburetor was made in an attempt to achieve what were thought to be correct readings in main rotor RPM and EGT after replacement of both gauges. The company owner attributed the piston seizure to the re-jetting. The skid shoes were new and had been tested only on concrete. The owner said that the design contributed to the damage to the helicopter. Probable Cause the inadequate design of the helicopter skid shoes. Factors related to the accident were: false indications of rotor RPM and EGT which led to seizure of the piston.
Full Narrative
On July 27, 1995, at 0930 central daylight time, an amateur built Revolution Helicopter Mini-500, N500ZZ, registered to Revolution Helicopter Corp. of Excelsior Springs, Missouri, and piloted by a commercial helicopter pilot, experienced a total loss of engine power while in cruise flight. During an auto rotational (forced) landing, one-half mile west of Wittman Regional Airport, Oshkosh, Wisconsin, the helicopter sustained substantial damage. The pilot reported no injuries. The local 14 CFR Part 91 flight was operating in visual meteorological conditions. No flight plan was on file. The flight departed at 0920. The accident occurred during the annual Experimental Aircraft Association's convention. The helicopter was conducting a demonstration flight in the vicinity of the airport at Oshkosh, Wisconsin.
Personal Information
The pilot had obtained approximately 100 hours flight time in this type of helicopter, at the time of the accident. This was the first flight of the day.
Aircraft Information
The helicopter had accumulated 210 hours time in service at the time of the accident with less than one hour since inspection and maintenance to the carburetor which included changing the jetting.
Wreckage And Impact Information
The helicopter impacted the terrain during a forced landing in an open field approximately one-half mile west of Wittman Regional Airport, Oshkosh, Wisconsin. There were two ground scars consistent with the size and shape of the skids running westerly from the first visible impact mark to the wreckage. The left skid was broken away from its mounting. The tail boom was lying to the north of the main wreckage and exhibited sharp fractures at the broken end. The tail rotor blades were bent. The main rotor blades were bent and broken and one had red paint on it similar to the color of the tail boom. Subsequent examination of the engine found that the rear piston was seized in the cylinder. The owner of the company producing the helicopter said that two changes to the helicopter just prior to the flight were of concern. He stated that a new rotor/engine RPM instrument was installed at the same time as a new exhaust gas temperature (EGT) gauge. He said that prior to the installation of these gauges that the helicopter was operating without incident; however after reading the indications on these new instruments re-jetting of the carburetor was done in an attempt to bring the readings within gauge limits. The owner attributed the seizure to the previous accomplished re-jetting. He said that at the same time a new set of skid shoes were installed on the skids of the helicopter and testing was done on concrete only. When an autorotational landing was conducted in a crop field the new skid shoes dug in and stopped the helicopter in a short distance, failing the left skid and fracturing the skid shoe on that skid.
Additional Data/Information
The NTSB did not exercise its right to retain custody of the wreckage. When the on scene investigation was complete the wreckage was removed and retained by the owner. Party to the investigation was the Federal Aviation Administration, Flight Standards District Office, Milwaukee, Wisconsin.
RHCI INVESTIGATIVE FINDINGS
As published in the September 1995 “Reaching the Customer” newsletter, the following report was written by Brian Thomas (RHCI’s Test Pilot):
Many of you have been asking questions about the autorotation capabilities and crashworthiness of the Mini-500. Well, I will answer some of those questions, but this time with an actual experience...
Oshkosh was less than a week away, the composite department was still in the learning stage and needed much supervision, and the assembly manual was a priority. Our minds were divided onto these other projects while we were working on preparing the aircraft for the show. As a result of this, we made three mistakes which caused this whole incident.
First, we installed a new rotor/engine tachometer in the aircraft just before the fly-in. We thought the gauge was calibrated correctly. Also, we were using a new EGT gauge that was supposed to be self-compensating for temperature. The week before Oshkosh, the temperature at the factory was 95 to 100 degrees F. with 95% humidity. After making these changes, the aircraft experienced a loss in performance. Our EGT temperatures were only running about 900 to 1000 degrees F. We attributed this loss of performance to the high temperature and humidity. Using the EGT gauge as a guide, we leaned the mixture by installing much smaller main jets and lowering the needles. This brought the temperature up to 1100 and 1200 degrees F., but with no significant increase in performance. Through testing, we then learned that the rotor/engine tachometer was calibrated too low. After re-calibration, our performance returned. EGT’s were still reading normally and were left as changed. I immediately conducted a short test flight and everything seemed to be working well.
Second, we installed wear shoes on the bottom of the skids to prevent excessive wear on concrete and rocky surfaces. Our intentions were to make this an option later. These shoes consisted of eight pieces of steel, four per skid, approximately five inches long, riveted with six rivets each, evenly spaced along the skids.
Third, we did not test the skid shoes on grass or dirt to see if they would change the run-on landing performance.
Now for what happened at Oshkosh. It was the first flight on the first day of the show. I started the aircraft and hovered around the grass runway for a few minutes and the aircraft was operating normally. I then departed and entered the traffic pattern. On my first trip around the pattern, the aircraft was performing perfectly. I was keeping an eye on the EGT gauge to make sure that the temperatures were still good, since it was cooler at Oshkosh than at the factory. The temperature was still 1100 and 1200 degrees F. On my second trip around the pattern, the engine suddenly stopped. The EGT gauge that we installed was not as accurate as we thought and the engine hot seized. At the time the engine quit, I was at 300 feet AGL with an airspeed of 70 MPH. I entered autorotation and steered for a nearby clover field. The autorotation was uneventful, as was the flair and touchdown.
As I have previously said, the Mini-500 is one of the best autorotating helicopters I have ever flown. The problems began during the ground slide. Immediately upon touchdown, the skid shoes caught in the clover and soft dirt so hard that one shoe was pulled off the skid! The left skid caught and jerked so hard that the legs buckled. The legs did not buckle because they are not strong enough. They buckled from the enormous force of trying to stop 730 lbs. of aircraft so quickly. The skid shoes were the cause, not the legs. When the left skid buckled, the aircraft started to go onto its left side. As a result, one rotor blade contacted the tail boom. Part of the reason that the skid shoes caught so hard is that the normal procedure for the Mini-500 is to lower the collective all the way down after touchdown from an auto. On most helicopters with skid shoes, the procedure is to hold the collective up until the helicopter comes to a stop to prevent the shoes from digging in too badly. I am very familiar with this procedure, but failed to relate it to the Mini-500.
(2) NTSB Identification: LAX96LA150
Accident occurred Mar-31-96 at San Carlos, CA
Aircraft: Lampert Revolution M500, registration: N750GL
Injuries: 1 Minor
According to FAA airman records, the pilot did not hold a rotorcraft category rating. FAA inspectors examined the pilot's logbook and reported that he received a solo endorsement in helicopters about 1 1/2 years ago. The pilot was returning to the airport following a local area flight. About 1 mile west of the airport, the pilot began to smell something burning and said he sensed something was wrong. Shortly thereafter, he heard a "slap" sound as the helicopter transitioned through 50 feet and 50 knots about 1/4 mile from the runway. The pilot stated that he "didn't do anything [with the controls] but keep it headed for an open area between the taxi way and the runway." The pilot said he did not flare or touch the collective, and the helicopter hit hard in the open area and rolled on its left side. An FAA airworthiness inspector examined the helicopter and found the engine to transmission drive belt fragmented, with rubber transfer throughout the engine compartment. Rubber transfer on the pulleys showed a forward movement pattern of the belt off the pulley. The inspector reported that the pulley was designed without a flange or other means to keep the belt aligned.
Probable Cause
The pilot's failure to recognize a drive train disengagement and initiate an autorotation. The inadequate engine-to-transmission drive belt/pulley design, and the pilot's limited training and experience in rotorcraft operations were factors in this accident.
Full Narrative
On March 31, 1996, at 1347 hours Pacific standard time, a homebuilt experimental Lampert Revolution M500 helicopter, N750GL, collided with the ground and rolled over during landing at San Carlos, California. The aircraft was owned, built, and operated by the pilot. Visual meteorological conditions prevailed at the time and no flight plan was filed. The helicopter sustained substantial damage. The non-rotorcraft rated private pilot, the sole occupant, sustained minor injuries. The flight originated at Half Moon Bay, California, on the day of the accident at 1315 as a personal cross-country flight to San Carlos. According to FAA airman records, the pilot does not hold a rotorcraft category rating. FAA inspectors examined the pilot's logbook and reported that he received a solo endorsement in helicopters about 1 1/2 years ago. The pilot reported that he flew from San Carlos to Half Moon Bay earlier in the day and was returning to the San Carlos airport. About 1 mile west of the airport the pilot began to smell something burning and said he "sensed something was wrong." Shortly thereafter, he heard a "slap" sound as the helicopter transitioned through 50 feet and 50 knots about 1/4 mile from the runway. The pilot stated that he "didn't do anything [with the controls] but keep it headed for an open area between the taxi way and the runway." The pilot said he did not flare or touch the collective and the helicopter hit hard in the open area and rolled on its left side. An FAA airworthiness inspector examined the helicopter and found the engine to transmission drive belt fragmented, with rubber transfer throughout the engine compartment. Rubber transfer on the pulleys showed a forward movement pattern of the belt off the pulley. The inspector reported that the pulley is designed without a flange or other means to keep the belt aligned.
RHCI INVESTIGATIVE FINDINGS
RHCI was allowed to investigate the damaged aircraft with the FAA present in an attempt to discover why the belt failure occurred. It was explained to the FAA investigator how the belt alignment worked, and the flanges on the sprocket were pointed out to him at that time. They were in place and functioning. There was another Mini-500 in the same hanger built by the same person, but not yet flown. RHCI showed the FAA inspector that the belt on the crashed Mini-500 had not been properly aligned, and that the same mistake was made on the other Mini-500 he built as well. It is unknown why the inspector said the sprocket was designed without a flange or other means to keep the belt aligned, even when RHCI showed him the flanges and explained their operation, but RHCI had no influence on the outcome of an NTSB or FAA investigation. With hundreds of Mini-500 now flying, the belt alignment system has obviously proved itself if properly installed and maintained.
(3) NTSB Identification: LAX97LA150
Accident occurred Apr-16-97 at Lihue, Kauai, HI
Aircraft: Duff Mini-500, registration: N13118
Injuries: 1 Fatal
A witness stated that the helicopter appeared to be about 500 feet AGL and that he could hear a "tick-tick-tick" sound as the aircraft started yawing to the left and right. The yawing motion was followed by a left roll to an inverted attitude from which the aircraft descended nose down to the ground and crashed. At the time that the roll began, the tail rotor and gearbox were observed to separate from the tail boom. Examination of the helicopter did not disclose any pre-accident engine, fuel system, or flight control system malfunctions or abnormalities. Black paint, the color of the tail boom, was evident on the leading edge of both main rotor blades, and four impact dents were found on the tail boom. Paint transfer indicated that the upper right-hand windshield had also been impacted by the main rotor blades. Review of the student pilot's flight records disclosed that he had obtained 12 hours of helicopter dual instruction in 1991, with only 1 hour listed for autorotations. No record of additional dual instruction was found between 1991 and the date of the accident.
Probable Cause
the student pilot's improper use of the helicopter flight controls, which resulted in rotor contact with the tail boom and loss of control. Factors relating to the accident were: the pilot's lack of total and recent training and experience in airborne control of helicopters.
Full Narrative
On April 16, 1997, at 1424 hours Hawaiian standard time, a single-place Duff Mini-500 homebuilt experimental helicopter, N13118, was destroyed when it impacted the ground in the vicinity of Lihue, Kauai, Hawaii. The student pilot was fatally injured. The flight departed from the pilot's Anahole residence for an unknown destination. No flight plan was filed for the personal flight and no en route communications were received by any Federal Aviation Administration (FAA) facility. An eyewitness, who was approximately 1/4 mile from the crash location, stated that the aircraft appeared to be about 500 feet AGL, and that the engine did not sound as if it was maintaining a steady RPM. The aircraft was then observed to start yawing to the left and right, which was followed by a left roll to an inverted attitude, from which it descended nose down to the ground. At the time the final roll began, the tail rotor and gear box were observed to separate from the tail boom. The witness also stated that he heard a "tick-tick-tick" sound emanating from the aircraft at the time that it appeared to be in trouble. The helicopter was examined by an FAA airworthiness inspector from the Honolulu, Hawaii, Flight Standards District Office, with the technical assistance of the aircraft kit manufacturer's safety investigator. According to their report, which is appended to this report, the fuel system was intact and without obstructions. The system was equipped with a motorcycle fuel filter, but no debris or obstructions were found in the filter and there was no evidence of a fuel problem. All control system linkage breaks that were found appeared to have resulted from fracture and not fatigue, and all rod ends that were broken had first been bent. The engine exhaust manifold bolts and head bolts were found to be finger tight. The internal parts of the engine were in new condition and correctly assembled. One manufacturer's bulletin on the carburetor, which specified a change in jets, had not been complied with; however, the inspector stated that the engine had been running rich so the noncompliance was not considered significant. The electronic engine ignition system was intact and functional. The engine contained coolant and oil, and no evidence was found that would indicate an engine problem. The main transmission and tail rotor gear box contained lubricant. The tail rotor gear box was severed in half but the internal gears were in new condition. The tail rotor blades were bent and one main rotor blade had separated from the rotor head and was found 30 feet away from the aircraft. Black paint, the color of the tail boom, was evident on the leading edge of both main rotor blades, and four impact dents were found on the tail boom moving progressively towards the cockpit. The upper right-hand windshield was separated from the airframe with a smear of paint transfer identical to the main rotor blade color. The FAA inspector stated that the student pilot's records indicated that he had received 12 hours of helicopter flight instruction in 1991, of which a total of only 1 hour was logged for both autorotation and pattern flight. Five years later, and without any known additional instruction, the pilot obtained and assembled a Mini-500 helicopter and proceeded to train himself to fly it after a flight instructor endorsement for solo flights that the FAA stated was in violation of FAR's 61.59, 61.87, 61.189, and 61.195.
RHCI INVESTIGATIVE FINDINGS
The FAA asked RHCI to join the Investigation Team in an attempt to establish a cause for the accident. RHCI compiled information through the local police department, eye witnesses, friends of Mr. Duff, and the NTSB and FAA.
After RHCI’s examination, it is RHCI’s opinion that no mechanical failures occurred during the aircraft's last flight, and if it were not for the crash, the aircraft could be flying today. By compiling the evidence, RHCI believes that the best scenario which led to the crash is as follows:
Mr. Duff had received 12 hours of helicopter flight instruction back in 1991. Only one hour during this time was logged for both autorotations and pattern flight. Five years later, and without any further instruction, Mr. Duff assembled a Mini-500 helicopter kit and proceeded to train himself to fly it. During his third flight, and his longest cross country, Mr. Duff probably allowed his rotor blades to lose RPM to the point that the low rotor warning light and the low rotor warning horn alerted him of this situation. Without the proper experience and training, Mr. Duff overreacted and overspun the rotor system in an attempt to normalize his RPM. The aircraft yawed to the right, and then again yawed to the left as he chopped power to avoid the overspin. While the aircraft was yawing, he would have been trying to regain control of the cyclic, collective and anti-torque pedal systems. His responsibility was then overloaded and he failed to catch up with the controls and decayed his rotor RPM to the point that the centrifugal force of the blades was not great enough to hold them in their plane. The oncoming forces of airflow and retreating blade stall caused the aircraft to roll left and then invert. What RPM was left in the rotors then allowed them to contact the tail boom, striking it with such force that it broke the tail rotor gear box off of the tail boom. The rotors also folded and contacted the cockpit. The pilot lost control, and then lost RPM and failed to recover. The aircraft then impacted the ground at a speed well in excess of 100 MPH. The pilot instantly died from impact. The cause of the crash was pilot error, due to his inability to fly a helicopter.
(4) NTSB Identification: CHI97LA222
Accident occurred Jul-19-97 at Ava, MO
Aircraft: Morgan Mini-500, registration: N500XM
Injuries: 1 Uninjured
On July 19, 1997, at 1315 central daylight time, an experimental Mini 500 helicopter, N500XM, was substantially damaged during a forced landing near Ava, Missouri. The pilot reported that the engine lost power during cruise. He was not injured. The 14 CFR Part 91 flight had departed Cabool, Missouri, about 1245 with a planned destination of Ava, Missouri. Visual meteorological conditions prevailed and no flight plan was filed.
RHCI INVESTIGATIVE FINDINGS
The NTSB had this Mini-500 delivered to RHCI to help in the investigation. With the NTSB present, it was discovered that the original airplane jetting was still installed in the carburetors. The engine failed due to high EGTs from failure to follow instructions and re-jet the engine upon installation for helicopter use. The helicopter landed on the side of a 30 degree hill, and rolled over.
(5) NTSB Identification: LAX97LA269
Accident occurred Jul-31-97 at Agua Dulce, CA
Aircraft: Mitteer Mini-500, registration: N501GM
Injuries: 1 Serious
The pilot of the recently completed, kit-built helicopter, stated that the engine stopped abruptly about 150 feet above helipad elevation as he was on base leg for landing. A hard landing resulted from an unsuccessful autorotation. Examination of the helicopter revealed that the size of the metering jet installed in both carburetors by the owner/pilot was too small, and that the fuel metering pin in both carburetors was improperly set so as to create an excessively lean fuel/air mixture, which resulted in loss of engine power. The pilot reported having 50 hours total helicopter flight time and that he last practiced autorotations 22 years prior to the accident. A revised aircraft assembly manual, which added a discussion of fuel jets and metering pins, was offered to holders of the earlier manual at a reduced price; however, the owner/builder did not purchase it. An article in the manufacture's newsletter, again discussing the importance of this subject, was sent to the owner/builder's address of record.
Probable Cause
Failure of the owner/builder to obtain and comply with service literature from the kit manufacturer, which resulted in improper setting of the carburetor fuel mixture and led to loss of engine power. An additional cause was the pilot's failure to successfully autorotate the helicopter to an emergency landing. The pilot's lack of total experience in the type helicopter and lack of recent experience in performing autorotations were related factors.
Full narrative
On July 31, 1997, at 1945 hours Pacific daylight time, an experimental (amateur built) Mitteer Mini 500 helicopter, N501GM, was substantially damaged when it collided with terrain while on landing approach to a private helipad at Agua Dulce, California. The commercial pilot was seriously injured. Visual meteorological conditions prevailed for the personal flight. The recently completed helicopter departed from the helipad about 1940. According to the pilot's brother, the pilot related from his hospital bed that the engine stopped abruptly about 150 feet above helipad level as he was on base leg for landing. Because previous approaches had been at too steep an angle, the pilot was deliberately flying a flatter and slower approach, which, together with his low altitude when the engine failed and lack of a suitable landing site, made his autorotation unsuccessful. According to inspectors from the Van Nuys Flight Standards District Office, the aircraft impacted on a two-lane asphalt road about 1/8 mile from the helipad in a valley about 100 feet below the helipad elevation. Terrain slopes upward about 45 degrees on one side of the road and there are power transmission lines on the other side of the road, however, the helicopter contacted neither prior to impacting on the roadway. The impact bent both landing skids outward and the belly of the fuselage contacted the pavement. The pilot's seat structure exhibited compression failure with more collapse on the left side than the right side. The two rotor blades had minor damage on the lower surface of the tips. After impact, the aircraft rotated 90 degrees to the right and came to rest about 10 feet away from the impact mark, resting on its left side. According to the inspector, no airworthiness certificate or operating limitations had been issued to the builder/pilot by the Federal Aviation Administration. The recording hour meter in the aircraft indicated 8.4 total hours, however, the pilot told his brother that he had operated the aircraft more than those hours. The pilot's logbook indicated total operating time since new, including ground run time, of 14.8 hours. The first entry was about a month before the accident. The last entry in the logbook, for the previous flight, indicates that the pilot changed the fuel metering jets in the carburetors to "150" size. The pilot reported having 50 hours total helicopter flight time, with 18 hours in the previous 60 days. In a telephone conversation with the Safety Board in December, 1997, the pilot said that he received his helicopter training in 1975 in a Bell 47 helicopter, and that was the last time he practiced an autorotation to landing. In June, 1997, prior to first flying his Mini 500, he took 2 hours of dual instruction in a Robinson R-22, but did not perform any autorotation practice. Representatives of the company which manufactures the parts kit for the helicopter, examined the aircraft and determined that the size of the metering jet installed in both carburetors by the owner/pilot was too small, and that the fuel metering pin in both carburetors was improperly set so as to create an excessively lean fuel/air mixture in the engine. Examination of the aft piston of the two cylinder engine through the exhaust port showed scoring on the sides of the piston and evidence of "hot seizure." A manufacture's bulletin on the subject of sizing metering jets and metering pins in the carburetor to control exhaust gas temperature was issued on May 7, 1996, the same day the kit was shipped to the manufacture's dealer. The dealer signed and returned a receipt for the bulletin to the manufacturer who placed it in the file for the aircraft serial number. The kit was sold to the builder/pilot on January 13, 1997, and there is no record whether there was a copy of the service bulletin with the kit. An article in the manufacture's newsletter of March, 1997, discussed the importance of this subject again. According to the kit manufacturer, the newsletter was mailed to the builder/pilot's address of record, which was his business address. A revised aircraft assembly manual which added a discussion of fuel jets and metering pins was offered to holders of the earlier manual at a reduced price. The owner/builder did not purchase the revised manual.
RHCI INVESTIGATIVE FINDINGS
The NTSB invited RHCI to help in the investigation. With the NTSB present, it was discovered that the jetting was incorrectly installed in the carburetors to the maximum lean settings, and the EGT gauge was labeled by the pilot at a red line of 1300F. The EGT should never run more than 1150F. The engine seized due to high EGTs from improper jetting. The accident was caused from failure to perform successful autorotation. In fact, the rotor blades were nearly undamaged and not turning at the time of impact. It is believed the helicopter fell more than 50 feet, and hit on a hard paved road.
(6) NTSB Identification: IAD97LA113
Accident occurred Aug-23-97 at New Philadelphia, OH
Aircraft: Haines Revolution Mini-500, registration: N7240E
Injuries: 1 Uninjured
On August 23, 1997, at 1045 eastern daylight time, a Haines Revolution Mini 500, homebuilt helicopter, N7240E, was substantially damaged when it collided with the ground during takeoff at Harry Clever Field, New Philadelphia, Ohio. The certificated private pilot was not injured. Visual meteorological conditions prevailed for the local, personal flight that originated at New Philadelphia, Ohio. The flight was conducted under 14 CFR Part 91 and a visual flight rules flight plan was not filed. According to a Federal Aviation Administration (FAA) Safety Inspector, the pilot was taking off, and about 50 feet above the ground, the rotor RPM started to decay. The pilot said he applied more power, but the engine sputtered, and shortly thereafter the engine lost power. The pilot said he entered autorotation, but he did not have enough rotor speed to land safely, and the helicopter struck the ground. According to the pilot, he had flown the helicopter for an hour the day before, and he had refueled the helicopter the day of the accident. The fuel tank, fuel lines, fuel filter and fuel pump were examined after the accident by the FAA Inspector. According to the Inspector, the examination did not disclose any contaminants. The helicopter was moved to a hangar for further examination.
RHCI INVESTIGATIVE FINDINGS
It was reported to RHCI that the pistons had holes burnt through them, and the tongues were gone from the spark plugs. This can happen only with the use of low octane fuel or if the cylinder head of the engine has been modified to increase compression ratio. It was reported to RHCI that the aircraft was freshly refueled at the airport gas pump. The cause of engine failure was due to pre-detonation of fuel. It is suspected by RHCI that the gas used prior to the flight was less than 87 octane, which is usually the grade offered by airports in auto gas. If the gas is in the ground for a long period of time, it will lose octane, and low octane gas will pre-detonate in the Rotax engine, as explained in the Rotax manual. The cause of the accident was failure to perform a successful autorotation.
(7) NTSB Identification: FTW97LA328
Accident occurred AUG-26-97 at Huffman, TX
Aircraft: Fingerhut Revolution Mini-500, registration: N570F
Injuries: 1 Uninjured
The student pilot experienced a disconnect of the collective control system which resulted in the main rotor blades going to flat pitch while in cruise flight at 800 feet MSL. When the pilot attempted to cushion the landing by increasing collective pitch, the helicopter yawed to the left prior to touching down and the helicopter rolled over on its side. Examination of the wreckage revealed a disconnect of the collective flight control system between the collective riser block (P/N 0153), and the rod end (P/N 0600) for the collective control tube. Examination of the threaded areas of the collective riser block and the rod end revealed that the threads on the aluminum collective riser block were found to be displaced or pulled out due to inadequate improper penetration. The information supplied by the kit manufacturer was insufficient to properly rig the flight control system.
Probable Cause
The disengagement of the helicopter's collective control tube due to improper installation by the builder. Factors were the lack of sufficient information provided by the kit manufacturer and the pilot's inability to cushion the landing.
Full Narrative
On August 26, 1997, at 2000 central daylight time, a Fingerhut Revolution Mini 500 homebuilt helicopter, N570F, was substantially damaged during a forced landing near Huffman, Texas. The student pilot, sole occupant of the helicopter, was not injured. The helicopter was owned and operated by the pilot under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the local flight for which a flight plan was not filed. The instructional flight originated from a helipad at the pilot's home in Huffman, Texas at 1945. According to the pilot, he experienced a disconnect of the collective control system which resulted in the main rotor blades going to flat pitch while in cruise flight at 800 feet MSL. The pilot added that he elected to execute a running landing to a cultivated field rather that try to land in a confined helipad. During the landing flare the helicopter yawed to the left as the pilot applied collective to cushion the landing prior to touching down. The pilot added that the helicopter was not properly aligned during touch down and the helicopter rolled over on its side. The FAA inspector confirmed that the 1997 model helicopter sustained structural damage. He added that the student pilot was properly endorsed for solo flight and had accumulated a total of 50 hours of flight in helicopters, of which 28 were in the same make and model. According to the aircraft maintenance records, the helicopter had accumulated a total of 28 hours since it was assembled by the pilot from a kit. Flight control continuity was confirmed by the FAA inspector to the cyclic and anti-torque systems of the helicopter. Examination of the helicopter by the FAA inspector revealed that a disconnect of the collective flight control system between the collective riser block (P/N 0153), and the rod end (P/N 0600) for the collective control rod (P/N 0002) With the aid of 10 power magnification, the inspector examined the threaded areas of the collective riser block and the rod end. The threads on the aluminum collective riser block were found to be displaced or pulled out. See enclosed drawing showing the 0.314 inch penetration on the threaded surface of the riser block and the first 0.388 inch engagement on the rod end. The FAA inspector also noted that the control rods provided by the helicopter manufacturer were not provided with a "witness hole" so either the installer or an inspector could verify the amount of rod end penetration into the threaded control tube. Furthermore, the assembly instructions provided by the manufacturer did not stipulate the minimum amount of thread engagement required in any of the rod ends in any of the flight control tubes in the helicopter, nor did it warn the potential builder of the criticality of proper thread engagement and security. To assist with the investigation, the FAA inspector inspected a like helicopter to establish a comparison on the installation of the flight control systems. The comparison between the two installations revealed that a pronounced difference existed in the length of exposed threaded areas between the rod ends and the control rods. The owner/builder of the helicopter provided the FAA inspector with the plans and instructions provided to him by the kit manufacturer during the assembly of the helicopter.
RHCI INVESTIGATIVE FINDINGS
This Mini-500 was first owned and built by a previous person. The new owner was the pilot at the time of the accident. After the accident, the FAA reported to RHCI that a rod-end that operates the collective control had pulled out of the aluminum collective riser block due to threads stripping out of the block. The reason was improper installation by the builder. Instead of screwing the rod into the block until 1/4” of threads are visible after tightening the jam nut as the manual clearly states, this builder screwed the rod into the block only 1/4” and then tightened the jam nut. That allowed only 4 threads to enter the block and although the rod end could not turn or back out, by design, the threads finally failed in time due to applied forces through normal operation. “Witness holes” are not necessary because the manual plainly states the depth necessary for installation. RHCI points the ability of the new pilot to still maintain control of his disabled aircraft, and the ability of the Mini-500 to still be controlled even with loss of this vital control function.
(8) NTSB Identification: FTW97LA339
Accident occurred Sep-09-97 at Idabel, OK
Aircraft: Roddie Mini-500, registration: N42JR
Injuries: 1 Fatal
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On September 9, 1997, at 1500 central daylight time, a Roddie Mini-500, homebuilt helicopter, N42JR, registered to and operated by the pilot, was destroyed while maneuvering near Idabel Airport, Idabel, Oklahoma. The airline transport rated pilot, the sole occupant, was fatally injured. Visual meteorological conditions prevailed and no flight plan was filed for the Title 14 CFR Part 91 personal flight. The flight originated from Idabel Airport at 1440. A witness, who was located at the airport, reported that the pilot performed a run-up on the ground before departing. The witness stated that the aircraft was operating approximately 2000 feet above ground level and about 500 feet from the approach end of runway 35. The witness then observed the aircraft in a nose low attitude. Then he "saw pieces" of the aircraft "fly" from the aircraft. The main fuselage came to rest on its right side, 1300 feet from the approach end runway 35. The instrument panel was found 157 feet south of the main fuselage. The tail rotor, including the vertical and horizontal stabilizers, came
to rest 400 feet south of the main fuselage. A close friend of the pilot, who also assisted in manufacturing the kit helicopter, reported that new rotor blades were installed on the day prior to the accident.
RHCI INVESTIGATIVE FINDINGS
A witness reported to RHCI that the low time 50+ hours helicopter pilot was going to attempt the first autorotation in his new Mini-500. The witness warned him not to do so because he lacked experience in helicopters. The witness reported that the pilot radioed to the ground as he prepared to enter autorotation. The cause of the accident was improper entrance into autorotation due to lack of experience in a new and unfamiliar machine.
(9) NTSB Identification: LAX97LA326
Accident occurred Sep-13-97 at San Carlos, CA
Aircraft: Lampert M500, registration: N800GL
Injuries: 1 Minor
The pilot reported that the engine lost power, while he was holding short of a taxi way in a hover. The helicopter landed hard on its right skid and rolled over on its right side. Witnesses reported that they observed the helicopter at about 20 feet AGL, when they heard the engine abruptly cease. They then reported seeing the pilot release the collective control with his left hand and apply full aft cyclic with both hands. The helicopter then pitched up to an approximately 45-degree angle while simultaneously falling. The helicopter and the airframe were examined by an FAA airframe and powerplant mechanic, and an FAA airworthiness inspector. No discrepancies were noted. The pilot did not hold a rotorcraft category rating and no evidence was found that he was endorsed for solo privileges in rotorcraft within the previous 90 days.
Probable Cause
Loss of engine power for undetermined reasons, and the pilot's improper use of the flight controls following the loss of power. The pilot's lack of training/certification in rotorcraft operations was a factor in this accident.
Full Narrative
On September 13, 1997, at 1516 hours Pacific daylight time, a homebuilt experimental Lampert M500 helicopter, N800GL, crashed on the taxiway following a loss of engine power on approach to the San Carlos, California, airport. The aircraft sustained substantial damage, and the pilot, the sole occupant, incurred minor injuries. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was on file. The local area personal flight departed San Carlos at 1500 and was terminating at the time of the accident. In a recorded statement to the FAA, the pilot reported that he was inbound to the airport and was asked to hold short of a taxi way to avoid oncoming traffic. The pilot held the helicopter in a hover and complied with the hold short instructions. He said that at that time, "my engine went silent, the engine RPM dropped to zero, and the aircraft began to drop rapidly." The aircraft landed hard on its right skid and rolled over on its right side. The tail rotor driveshaft separated from the main transmission, and the T-tail separated from the vertical fin. In his written report, the pilot stated that he "could have denied a straight-in [approach] from the shoreline and entered a left-hand pattern to runway or taxiway 30 at the traffic pattern altitude thus allowing the chance of successfully deploying autorotation technique rather than the low flight with slight tailwind component thus being caught in the 'Dead Man's Curve'." The pilot also reported that on entering the autorotation he made a "slight cyclic maneuver into the wind to gain energy in the main rotors." He said that he was, "so low that I might have smacked my tail rotor when executing this maneuver." Witnesses stated that they observed the helicopter at about 20 feet AGL when they heard the engine abruptly cease. They reported then seeing the pilot release the collective control with his left hand and apply full aft cyclic with both hands. The helicopter then pitched up to an approximately 45-degree angle while simultaneously falling. Initial inspection of the aircraft at the accident site revealed that the fuel tanks were approximately 1/2 full. The helicopter and the powerplant were examined by a certified airframe and powerplant mechanic and a airworthiness inspector from the San Jose Flight Standards District Office. No discrepancies were noted during the examination. The engine was not seized and the spark plugs fired in order with hand rotation of the crankshaft. Fuel was found in the fuel tank and the carburetor bowl. A review of the carburetor icing probability chart disclosed that icing conditions were not present at the time of the accident. According to FAA Airman Records, the pilot does not hold a rotorcraft category rating. No evidence was found that the pilot was endorsed for solo flight in rotorcraft within the last 90 days. Repeated attempts were made to contact the pilot to schedule further aircraft inspection with no response. The aircraft was moved from the hangar and the owner has declined to provide its location.
RHCI INVESTIGATIVE FINDINGS
It was later reported to RHCI that the engine had no sign of stoppage. Also a witness reported to RHCI that he could hear the engine running until impact with the ground. From these reports, RHCI suspects that rotor RPM was lost, and it was not properly recovered. The pilot had low time in helicopters, and did not have a helicopter rating.
(10) NTSB Identification: LAX98LA021
Accident occurred Oct-26-97 at Long Beach, CA
Aircraft: Revolution Mini-500, registration: N7234Y
Injuries: 1 Serious
After taking off, the helicopter had climbed about 250 to 300 feet, when the engine abruptly lost power. The pilot attempted an autorotation, but said he was able to maintain only 80 percent rotor RPM, which was insufficient to prevent a hard landing. The pilot reported that the main rotor low pitch stop had recently been changed from -1.8 degree to -0.5 degree, as recommended by a factory representative. Also, the pilot stated that he was aware of a phenomenon called "cold-freeze" (engine seizure without over temp) that (according to him) had occurred with other engines of this make/model. He believed there was a possible engine seizure and that reduced settings of the rotor low pitch stops could have resulted in low rotor RPM. No pre-impact mechanical problem was found that would have resulted in loss of engine power.
Probable Cause
Loss of engine power and low rotor RPM for undetermined reasons. The factory representative's recommendation to reduce the main rotor low pitch stop (from -1.8 degree to -0.5 degree) may have been a related factor.
Full Narrative
On October 26, 1997, at 1233 hours Pacific standard time, a Revolution Mini-500 experimental helicopter, N7234Y, was destroyed and the commercial pilot seriously injured when it impacted terrain following takeoff at Daugherty Field, Long Beach, California. The aircraft had completed one circuit of the helicopter traffic pattern and landed on Helo Pad 3. It was then cleared for a second circuit of the helicopter traffic pattern. The pilot stated that on the second takeoff, the engine quit abruptly at an altitude of 250-300 feet AGL. He then attempted an autorotation, but could get only 80 percent rotor RPM which was insufficient to prevent a hard touchdown. (The pilot stated in his report that he felt this was due to a recent change in the main rotor low pitch stop from -1.8 deg. to -0.5 deg. which had been recommended by a factory representative.) The pilot also stated that he was aware of a phenomenon called "cold-freeze" (engine seizure without over temp) that had happened several times with the Rotax engine. He felt that a possible engine seizure, combined with the change in the rotor low pitch stop, were contributing factors to the accident rather than fuel starvation or mechanical malfunction of the helicopter.
RHCI INVESTIGATIVE FINDINGS
Upon RHCI investigation, it was discovered that the pilot was performing a maximum performance take off which developed low rotor RPM. It was reported that the engine did not quit, but the pilot encountered low rotor speed and failed to recover. It was also reported that upon examination of the engine there was no sign of stoppage, or failure. The pilot had very low time in helicopters. It is noted that the pilot had -1.8 degrees adjusted into his main rotor pitch. Proper pitch should be between -.05 and -1.0 degrees. Any more than -1.0 degree will tend to tuck the nose of the aircraft abruptly when entering an autorotation, and also increase the possibility of a tail boom strike. Before this accident, an RHCI test pilot flew this helicopter, performed successful autorotations, and reported that the aircraft performed properly.
(11) NTSB Identification: IAD98LA014
Accident occurred Nov-27-97 at Bluefield, WV
Aircraft: Jones Mini-500, registration: N8015E
Injuries: 1 Minor
On November 27, 1997, approximately 1430 eastern standard time, a Jones Mini 500, N8015E, sustained substantial damage when the experimental helicopter impacted the ground while maneuvering at Mercer County Airport, Bluefield, West Virginia. The certificated commercial pilot/builder received minor injuries. Visual meteorological conditions prevailed. No flight plan was filed for the local flight conducted under 14 CFR Part 91.
Full Narrative
On November 27, 1997, approximately 1430 eastern standard time, a Jones Mini 500, N8015E, sustained substantial damage when the experimental helicopter impacted the ground while maneuvering at Mercer County Airport, Bluefield, West Virginia. The certificated commercial pilot/builder received minor injuries. Visual meteorological conditions prevailed. No flight plan was filed for the local flight conducted under 14 CFR Part 91. The pilot reported that the purpose of the flight was to "balance and adjust the flight controls." While air taxiing, the pilot took off down wind and climbed to 50 feet AGL. The pilot stated that "after passing through transitional lift, the rotor began to over speed, so I reduced the throttle to maintain the rotor in the mid green." The pilot reported that he continued and as he approached the end of the runway, "I slowed the helicopter down and started a left turn with the intention of flying down runway to check the head balance." The pilot stated that, "as I started the turn I increased the throttle to the maximum, however, the rotor RPM had deteriorated and the throttle would not bring it back up." The pilot reported that he did not have sufficient altitude to unload the rotor and upon ground impact, the helicopter's left skid collapsed, rolling the helicopter onto its side damaging the main rotor, tail boom, tail rotor, and the cockpit. The pilot reported to the Federal Aviation Administration (FAA) Inspector that he had thousands of hours in turbine powered helicopters, and approximately 10 hours in reciprocating engine powered helicopters. The FAA Inspector examined the wreckage. The examination confirmed flight control continuity and no mechanical malfunction was found in the engine.
RHCI INVESTIGATIVE FINDINGS
The pilot developed low rotor RPM and did not properly recover.
(12) NTSB Identification: NYC98LA049
Accident occurred Dec-19-97 at Gettysburg, OH
Aircraft: Bihn Mini-500, registration: N727EB
Injuries: 1 Fatal
On December 19, 1997, about 1450 eastern standard time, a homebuilt helicopter, a Bihn Mini 500, N727EB, was destroyed during a forced landing and collision with terrain near Gettysburg, Ohio. The certificated airline transport pilot was fatally injured. Visual meteorological conditions prevailed for the personal flight that originated at the Phillipsburg Airport, Phillipsburg, Ohio, about 1415. No flight plan had been filed for the local flight conducted under 14 CFR Part 91. According to witnesses, the helicopter was observed in level cruise flight, at 900 to 1,200 feet above the ground, when they heard the engine noise of the helicopter decrease. This was followed by the sound of two "pops," as witnesses observed the tail of the helicopter raise up, and an object depart from the helicopter. The helicopter then descended below tree level. According to a Federal Aviation Administration (FAA) Inspector, examination of the wreckage revealed that it came to rest in an open field, 90 degrees nose down, with the forward ends of the skids imbedded about 1 foot into the ground. The tailboom was observed to have a flattened area on the upper surface. One rotor blade was separated from the main rotor hub, and was located about 900 feet back along the helicopter's flight path. The helicopter was equipped with a Rotax 582 engine. Initial examination of the engine did not reveal a reason for the decrease in engine noise. The pilot flew for a commercial airline and had logged in excess of 10,000 flight hours in airplanes. The pilot obtained his private pilot helicopter certificate during July 1997. He had accumulated 59 hours in helicopters, and all training had been conducted in the Robinson R-22. His next helicopter flight was logged in November 1997, in the Mini 500 that he constructed. At the time of the accident, it was estimated that he had logged about 10 hours of hover, and 2 hours of flight, in N727EB.
RHCI INVESTIGATIVE FINDINGS
The helicopter did not have an engine failure. RHCI was told by people involved with the low time 50+ hours helicopter pilot that the purpose for the flight was to perform his first autorotation in his new Mini-500. He was advised by these people not to practice these maneuvers, because it had been four months since he had last flown and a refresher course was needed. In the opinion of RHCI, the pilot was performing maneuvers in a new untrimmed aircraft that should have first been done by a more experienced pilot, and that the pilot needed additional instruction before attempting the maneuver.
(13) NTSB Identification: SEA98LA030
Accident occurred Jan-28-98 at Newberg, OR
Aircraft: Raser Mini-500, registration: N500YY
Injuries: 1 Uninjured
The pilot reported that he had just lifted off and attained an altitude of about 20 feet, when the engine experienced a loss of power. The pilot initiated an autorotation near the end of the airpark. The pilot stated that the helicopter was yawed slightly to the left on touchdown to a plowed muddy area. The right side landing skid collapsed and the helicopter rolled over. Inspection of the engine revealed that one of the two cylinders would not hold compression. Further inspection found evidence of overheating and damage to the rings on the piston. The pilot reported that the engine had been experiencing heating problems, and that he had also modified the carburetor.
Probable Cause a power loss resulting from overtemperature of a cylinder. The pilot's operation with known deficiencies was a factor.
Full Narrative
On January 28, 1998, at 1550 Pacific standard time, a homebuilt Raser Mini 500, N500YY, operated by the pilot as a 14 CFR Part 91 personal flight, collapsed the right landing skid and rolled over after initiating an autorotation as a result of a loss of engine power shortly after takeoff from Sportsman Airpark, Newberg, Oregon. Visual meteorological conditions prevailed at the time and no flight plan was filed. The helicopter was substantially damaged and the airline transport pilot, the sole occupant, was not injured. During an interview with a Federal Aviation Administration Inspector and subsequent written statement, the pilot reported that he had just lifted off and attained an altitude of about 20 feet, when the engine experienced a loss of power. The pilot initiated an autorotation near the south end of the airpark to a plowed muddy area. The pilot stated that the helicopter was yawed slightly to the left on touchdown. The right side landing skid collapsed and the helicopter rolled over onto its right side. Inspection of the engine revealed that one of the two cylinders would not hold compression. Further inspection of the cylinder found evidence of overheating and damage to the rings on the piston. The pilot reported that the engine had been experiencing heating problems, and that he had also modified the carburetor.
RHCI INVESTIGATIVE FINDINGS
RHCI suspects that improper jetting of the carburetors was the reason for engine failure, although the customer feels it was due to cold seizure. It should be known that a cold seizure can only occurr in two ways: One way is due to an insufficient warm up period upon starting, and the other could be due to a sticking thermostat that would release cold water to the engine head shortly after take off. This would be indicated by a high water temperature reading in a hover, and then a sudden drop in water temperature, causing shock cooling to the engine.
(14) NTSB Identification: MIA98LA137
Accident occurred Apr-20-98 at Lakeland, FL
Aircraft: Bennett M-500A, registration: N105WB
Injuries: 1 Uninjured
The pilot stated he was on base turn to final for a fly bye, when he experienced a 1 to 1 vertical vibration. He informed the tower that he was going to land, and started a deceleration. The helicopter veered to the right, and the pilot applied left antitorque pedal. The nose started to tuck down, then the helicopter collided with the ground and rolled over on its right side. Examination of the helicopter flight control system revealed a hex nut backed off the cyclic flight control push rod bolt, and the bolt became disconnected from the control yoke teeter block. This resulted in a loss of cyclic control.
Probable Cause
A hex nut on the cyclic flight control pushrod bolt had backed off for undetermined reason(s) and allowed the bolt to become disconnected from the control yoke teeter block, resulting in a loss of cyclic control and subsequent roll over during an emergency landing.
Full Narrative
On April 20, 1998, at about 1230 eastern daylight time, a Bennett M-500A, N105WB, experimental helicopter, registered to a private owner, operating as a 14 CFR Part 91 personal flight, crashed on landing at the Lakeland-Linder Regional Airport, Lakeland, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The helicopter sustained substantial damage. The commercial pilot reported no injuries. The flight originated from the Lakeland-Linder Regional Airport about 1 hour before the accident.
The pilot stated he entered the traffic pattern landing to the south at Chopper Town. He made a base turn and continued to final for a fly by, when he experienced a 1 to 1 vertical vibration. He informed the tower that he was going to land, and started a deceleration at 50 feet. The helicopter started to veer to the right and he applied left antitorque pedal. The nose started to tuck down, estimated at about 50 degrees nose down. The helicopter collided with the ground in a nose down attitude and rolled over on its right side.
Examination of the helicopter revealed that a flight control pushrod became disconnected (hex nut backed off the attaching bolt) from the control yoke teeter block, resulting in a complete loss of cyclic and collective control of the main rotor system. Review of aircraft logbooks revealed no maintenance had been performed on the flight control push rod since assembly of the helicopter 106 hours before the accident.
The manufacturer for the Mini 500 stated the registered owner sent a fax request ordering 20 Teflon DU bushings (part #0562) and 20 Teflon washers (part #0101) that are used in the flight control system. The request was made and filled on March 25, 1998, on invoice #25969. The manufacturer stated in order for the registered owner to remove the bushings and washers that it would be necessary to remove the MS21042L4 nut (part #0470) and the NAS144 bolt (part #0434) to replace the bushings and washers.
The registered owner stated that he ordered the parts that were listed on invoice 25969. He ordered the nuts to comply with Revolution Helicopter Airworthiness Directive (AD) #3101998 dated March 10, 1998. He elected to replace the control yoke (part #0024), bushings (part #0562, 2 each) and the Teflon washers (part #0101, 4 each). The replacement of these parts is accomplished by removing bolts #0365, and the control transfer plate #0023. It does not require the removal of the suspect bolt and nut assembly. Review of the Mini-500 Aircraft Assembly and Maintenance Manual Sub-Assemblies instructions verified the registered owner's comments.
RHCI INVESTIGATIVE FINDINGS
It was reported to RHCI by the builder and a person assisting him that all the Teflon DU bushings in the control system had been replaced prior to the fly-in. Just enough DU bushings and other parts were purchased from RHCI for this purpose. To comply with AD# 3101998 only requires two DU bushings be replaced, while the builder purchased 20. The failure of the control system occurred because a permanent all metal locking-nut came loose from a non-rotating area. It is suspected that the nut and bolt were reused or not tightened at all, because of the fact that all parts were purchased and replaced except for the nuts and bolts. These certified nuts and bolts simply do not come loose unless they are reused.
(15) NTSB Identification: MIA98LA161
Accident occurred May-13-98 at Villa Rica, GA
Aircraft: Revolution Mini-500, registration: N355RM
Injuries: 1 Uninjured
On May 13, 1998, about 1630 eastern daylight time, a homebuilt helicopter, a Revolution Mini-500, N355RM, registered to a private individual, operating as a 14 CFR Part 91 personal flight, crashed during a precautionary landing at Stockmar Airport, Villa Rica, Georgia. Visual meteorological conditions prevailed and no flight plan was filed. The helicopter received substantial damage, and the ATP-rated pilot was not injured. The flight originated from a private helipad at Cedartown, Georgia, about 45 minutes before the accident.
Full Narrative
On May 13, 1998, about 1630 eastern daylight time, a homebuilt helicopter, a Revolution Mini-500, N355RM, registered to a private individual, operating as a 14 CFR Part 91 personal flight, crashed during a precautionary landing at Stockmar Airport, Villa Rica, Georgia. Visual meteorological conditions prevailed and no flight plan was filed. The helicopter received substantial damage, and the ATP-rated pilot was not injured. The flight originated from a private helipad at Cedartown, Georgia, about 45 minutes before the accident. The pilot stated that while in cruise flight, he noticed a "high frequency vibration/buzz sound," together with increasing coolant and exhaust gas temperatures, and elected to land. His intention was to perform a run-on, precautionary landing onto the single runway at Stockmar Airport, but the runway was in use, and he used a grassy area adjacent to the runway. The pilot further stated he chose the grassy area because it appeared to have been newly "bush-hogged"; however, while in the landing flare, he realized too late that the mowed level of the grass was high enough to conceal small obstructions. The left landing skid collided with a large, partially hidden rock and the helicopter rotated counterclockwise abruptly about its vertical axis approximately 240 degrees. During the ground gyration, the main rotor severed the tailboom and the tail rotor assembly separated from the helicopter. Postcrash inspection of the aircraft revealed that less than a full quantity of engine coolant was contained in the reservoir. The pilot stated the cooling system is a closed system, and he is at a loss to explain the leakage. He states, "It should be noted that prior to flight on this date, (accident date) the aircraft was parked inside a hangar on a concrete floor at 7GA9, (Whitesburg, Georgia) and no visible evidence of a leak was noted on the floor. Further, the aircraft was landed on a concrete pad at the private residence at Cedartown, GA and no visible evidence of a water leak was noted on the concrete pad."
RHCI INVESTIGATIVE FINDINGS
A hose clamp was not properly tightened, and the engine lost coolant, causing the engine to overheat. If the water level is allowed to lower to the cylinder headcover of the engine, the engine could overheat. A small leak may occurr while under pressure, but not leak while sitting on the ground.
(16) NTSB Identification: FTW98LA234
Accident occurred May-20-98 at Grove, OK
Aircraft: Revolution Mini-500B, registration: N6144S
Injuries: 1 Minor
On May 20, 1998, at 0925 central daylight time, a Revolution Mini-500B experimental helicopter, N6144S, owned and operated by the pilot as a Title 14 CFR Part 91 personal flight, was destroyed during a forced landing near Grove, Oklahoma. Visual meteorological conditions prevailed, and a flight plan was not filed. The private pilot, sole occupant of the aircraft, sustained minor injuries. The flight originated from the Grove Municipal Airport, about 25 minutes before the accident. According to preliminary information, the helicopter experience a malfunction with its clutch or the clutch's drive belt. The pilot initiated a forced landing to a high school parking lot, and during the attempted landing, the helicopter impacted a pickup truck. The helicopter was destroyed by a post crash fire.
Full Narrative
On May 20, 1998, at 0925 central daylight time, a Harding Revolution Mini-500B experimental homebuilt helicopter, N6144S, owned and operated by the pilot, was destroyed during a forced landing following the loss of the main rotor drive near Grove, Oklahoma. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 CFR Part 91 personal flight. The private pilot, sole occupant of the aircraft, sustained minor injuries. The flight originated from the Grove Municipal Airport, about 25 minutes before the accident.
The pilot reported that he had adjusted the alignment of the main drive belt and engine. During the ensuing personal/test flight of the helicopter, while at a cruising altitude of 1,350 feet MSL, he felt a "sudden hesitation and [smelled the] odor of smoke." While he was "determining if [a] serious malfunction existed," the helicopter experienced a loss of main rotor drive and altitude, "along with a stronger burning odor." The pilot initiated an autorotation to a field adjacent to a school. However, prior to reaching the intended landing area, the helicopter struck a parked pickup truck, "flipped over, landed in [the] field and started on fire." The helicopter was destroyed by the postimpact fire. The pilot had accumulated a total of 59 flight hours in helicopters, of which 14 hours were accumulated in his homebuilt helicopter.
RHCI INVESTIGATIVE FINDINGS
The helicopter did not have a clutch failure. The drive belt was not properly aligned, causing a belt failure. Information about proper alignment was supplied on the Service Information Letter #040196.
(17) NTSB Identification: NYC98LA154
Accident occurred Jul-26-98 at Shermans Dale, PA
Aircraft: Johnson Revolution Mini-500, registration: N805JJ
Injuries: 1 Uninjured
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On July 26, 1998, about 1800 Eastern Daylight Time, a homebuilt Revolution Mini-500 helicopter, N805JJ, was substantially damaged during a forced landing at Yost Airport (32PA), Shermans Dale, Pennsylvania. The certificated private pilot was not injured. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. According to the pilot's written statement, after about 45 minutes of flight, he entered the traffic pattern at his destination, and descended during both the base leg and final approach. While on the final approach, at 20 to 30 feet of altitude, the engine "stopped dead ... no sputtering, no sign, just nothing." The helicopter landed hard, the left skid collapsed, the main rotor struck the tail boom, and the helicopter rolled over on its left side. According to a Federal Aviation Administration (FAA) Inspector, the fuel tank was approximately 1/3 full, and there was fuel in the glass bulb along the fuel line. There was sufficient engine oil in the oil tank and the throttle linkage was intact.
RHCI INVESTIGATIVE FINDINGS
From RHCI’s investigation and after discussing the accident with the pilot, the cause of engine failure was seizure due to improper jetting. Customer was experimenting with the different sizes of jets, and at the time of the accident, he had installed 155 main jets. If the proper needle jet and needle position are not installed according to RHCI’s instructions, AD’s and advisories, the engine will seize, and most likely this would happen in a descent where the improper needle jet arrangement will tend to lean the mixture the most.
(18) NTSB Identification: IAD98LA092
Accident occurred Aug-11-98 at Northampton, PA
Aircraft: Austin Revolution Mini-500, Registration: N2XK
Injuries: 1 Fatal
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On August 11,1998, at 1832 eastern daylight time, a homebuilt Revolution Mini 500 helicopter, N2XK, was destroyed during collision with terrain following an uncontrolled descent near Northhampton, Pennsylvania. The certificated commercial pilot was fatally injured. Visual meteorological conditions prevailed for the maintenance test flight that originated at Bangor, Pennsylvania, approximately 1800. No flight plan was filed for the flight conducted under 14 CFR
Part 91. In a telephone interview, one witness stated his attention was drawn to the helicopter because it sounded unusual. He said the helicopter was maneuvering approximately 200 feet in the air. The witness said: "I saw it circle around but it didn't sound too good. I heard it making these weird noises. It stopped in the air and then turned towards my house. I heard it go 'pow' then another sharp 'snap'. It sounded like a gunshot. Then I saw this piece flying. The helicopter rotated approximately one-quarter turn, the tail came up, the nose dropped, and then the aircraft fell out of sight." In a telephone interview, a second witness said his attention was drawn by the sound. He stated: "It sounded like a helicopter, but it had a funny sound, it had a rat-a-tat-tat sound. I couldn't see it, then I saw him make a right hand turn heading due west gaining altitude. I heard a 'poof-poof'...Just the sounds of the rotors didn't sound normal. I heard the lighter 'pop' and then the louder 'pop'." The witness stated the helicopter then descended behind a tree line out of view. The wreckage was examined at the site on August 12, 1998, by a team of Federal Aviation Administration (FAA) Aviation Safety Inspectors. All major components were accounted for at the scene. According to one Inspector's statement: "The helicopter wreckage showed a vertical impact where the aircraft wreckage remained within a very confined area. No wreckage was more than a few feet from the fuselage. The only part of the aircraft not within the main fuselage was one main rotor blade which was discovered over 400 feet from the aircraft. Upon further investigation of the crash site, I observed that the pitch horn (a casting) was fractured on one of the main rotor hubs and disconnected. The blade yoke was still attached but only about twelve inches of the blade was attached. This part matched with the blade assembly that was over 400 feet from the wreckage. The rest of the hub assembly was found intact and all control rods and assemblies were attached. The mast showed no signs of mast bumping or deformation. The tailboom assembly and tail rotor assembly showed no signs of main rotor blade contact nor prior damage before impact...the pitch change rod to the hub with the missing main rotor blade was loose and the jam nuts to the rod and bearings were loose and not torqued at all." On August 12, 1998, the Inspector visited the location where the helicopter was hangared and maintained. He found the construction manual for the helicopter opened to the section for the rigging and balancing of the rotor system and a copy of the "Revolution Helicopter Airworthiness Directive (AD) #09031997...New Dynamic Main Rotor System Balancing Procedures." According to Revolution Helicopter Corporation, Inc., the AD was "...Urgent (Must Be Complied With Before Further Flight)." The FAA Inspector interviewed the pilot's son regarding any work performed on the helicopter and the purpose of the flight. According to the Inspector's report: "His son informed me that he was assisting his father with rotor tracking by holding the tracking flag and his father was adjusting the blade track with the pitch change links. The son left prior to his father finishing the ground portion of the checks and when he returned the aircraft and his father were gone." Portions of the main rotor system were forwarded to the NTSB Materials Laboratory in Washington, D.C. for further examination.
RHCI INVESTIGATIVE FINDINGS
RHCI was told by the NTSB that they found the pitch change rod to the hub with the missing main rotor blade was loose and the jam nuts to the rod-ends and bearings were loose and not torqued at all. The pilot didn’t finish tightening the jam nuts on the pitch link change rods. The pilot took off to make a run, and in forward flight, the rod-ends screwed loose causing the blades to go so far out of track that the aircraft could no longer be controlled, causing rotor failure.
(19) NTSB Identification: MIA98LA236
Accident occurred Aug-30-98 at Hattiesburg, MS
Aircraft: Hall Revolution Mini-500, registration: N9GH
Injuries: 1 Uninjured
On August 30, 1998, about 1500 central daylight time, a Hall Revolution Mini 500 homebuilt helicopter, N9GH, registered to an individual, landed hard at Hattiesburg, Mississippi, while on a Title 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The airline transport-rated pilot was not injured and the helicopter received substantial damage. The flight was originating at the time of the accident.
Full Narrative
On August 30, 1998, about 1500 central daylight time, a Hall Revolution Mini 500 homebuilt helicopter, N9GH, registered to an individual, landed hard at Hattiesburg, Mississippi, while on a Title 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The airline transport-rated pilot was not injured and the helicopter received substantial damage. The flight was originating at the time of the accident.
The pilot stated that as he hovered forward at a brisk walk, he heard the low rotor RPM horn and reduced the collective control. The helicopter descended rapidly and touched down on the "toes" of the skids. The helicopter bounced back into the air and the cyclic control grip separated from the cyclic control stick. The cyclic control stick moved to the full aft position and the main rotor blades contacted the tail boom.
RHCI INVESTIGATIVE FINDINGS
The pilot allowed the aircraft to enter into a low rotor RPM condition from which sufficient lift could not be obtained to slow the aircraft’s forward speed and cushion the landing. According to the pilot, the cause of damage was control grip separating from the cyclic control stick which moved uncontrollably to the aft position, allowing the rotorblades to contact the aircraft tail boom. If this was the case, then damage may have been adverte if the cyclic grip had been glued in place as called for in the assembly manual.
(20) NTSB Identification: CHI98LA334
Accident occurred Sep-08-98 at Eden Prairie, MN
Aircraft: CulverMini-500, registration: N6269R
Injuries: 1 Uninjured
On September 8, 1998, at 1900 central daylight time (cdt), a Culver-Revolution Mini 500, N6269R, piloted by a private pilot, was substantially damaged when it collided with the ground shortly after a total loss of power while hovering. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot reported no injuries. The flight departed Eden Prairie, Minnesota, at 1850 cdt.
Full Narrative
On September 8, 1998, at 1900 central daylight time (cdt), a Culver-Revolution Mini 500, N6269R, piloted by a private pilot, was substantially damaged when it collided with the ground shortly after a total loss of power while hovering. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot reported no injuries. The flight departed Eden Prairie, Minnesota, at 1850 cdt.
The pilot said he had been hover-taxiing the helicopter between the approach end of runway 36 and the south taxiway for runway 09R. He said he had been hover-taxiing for about 10-minutes when "...the engine stopped unexpectedly [and it] settled to the runway and rolled over."
The on-scene investigation revealed no anomalies with the airframe, engine or control system that would prevent flight. Examination of the fuel system revealed a silicon-type sealant had completely blocked the supply side of the fuel filter.
According to the pilot/builder, he had used this material as a seal between the helicopter's fuel tank filler neck flange and fuel tank body. The helicopter's kit manufacturers instruction states that the builder is to "Place a 1/8-inch bead of MA300 from the adhesive kit around [the] hole circle through the centerline of [the mounting] holes." A copy of these instructions are appended to this report.
The kit manufacturer was contacted regarding the accident and pilot/builders use of the silicon-type material. The manufacturer representative was asked if there were any warnings in the construction manual against the use of the silicon-type sealant as the builder had done. He said there were no warnings, only instructions to use the MA300 material. He said the MA300 is an epoxy- type glue/sealant that does not break down when contacted by gasoline. He said the silicon-type sealant will dissolve when contacted by gasoline. The IIC suggested the company publish a manual change or communicate the need to use only the sealant recommended by them. The company agreed and said they would put a notice in the next builder's newsletter. A copy of the company's December 1998 newsletter is appended to this report.
RHCI INVESTIGATIVE FINDINGS
This report was taken by phone from Randy Culver on Thursday, September 10, 1998, by Rick Stitt, RHCI Project Engineer.
The aircraft was in translational lift with an indicated airspeed of 15 MPH. The engine lost power and the aircraft landed hard on the back of the skids and rolled over. The pilot did not receive any injury. The customer determined engine power loss was caused by silicone installed on the metal flange of the fuel tank neck, that came loose and plugged the fuel filter. The RHCI instructions (Sect. 5 page 21, Assy Instruction #4) recommend using MA300 in a 1/8" bead around the flange through the center line of each hole and securing with rivets and washers.
(21) NTSB Identification: CHI98FA353
Accident occurred Sep-19-98 at Cahokai, IL
Aircraft: Barklage Revolution Mini-500, registration: N611AB
Injuries: 1 Serious
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On September 19, 1998, at 1330 central daylight time (cdt), a Barklage Revolution Mini 500, N611AB, operated by a commercial pilot, was destroyed when on initial climb, the helicopter's engine lost power. During the subsequent emergency landing, the helicopter impacted into a soybean field. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under 14 CFR Part 91. There was no flight plan on final. The pilot sustained serious injuries. The cross-country flight originated at Cahokia, Illinois, at 1323 cdt, and was en route to St. Charles, Missouri.
RHCI INVESTIGATIVE FINDINGS
It has been reported to RHCI by the NTSB and Rotax that a foreign object was dropped into the crank case, and worked to the top of the piston and failed both spark plug tongues causing the engine to quit. It was reported to RHCI that upon take off the Mini-500 climbed to an altitude of 200 feet, and when crossing over a power line complex experienced a power lost. The pilot had not gained enough altitude to clear the wires, and needed to extend his autorotation in order to reach a suitable landing site on the other side. This maneuver used all available rotor inertia, causing the rotor system to slow in RPM to a point where the autorotation could not be continued.
(22) NTSB Identification: LAX99LA004
Accident occurred Oct-04-98 at Moorpark, CA
Aircraft: Burson Mini-500, registration: N418MB
Injuries: 1 Fatal
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On October 4, 1998, at an unknown time, a Burson Mini 500, N418MB, crashed in hilly terrain near Moorpark, California. The aircraft was destroyed, and the private pilot, the sole occupant, suffered fatal injuries. Visual meteorological conditions prevailed for the afternoon of the flight and no flight plan was filed, nor were any ATC services provided. The pilot's daughter reported that she accompanied the pilot to the takeoff/landing site and helped reinstall the main rotor blades, which had been removed to trailer the helicopter. She stated that her father reported that he would fly over the park where she was playing baseball, and would subsequently fly over the family residence, in approximately 45 minutes. She left the site at 1417. The daughter further recalled that the pilot reported that he would be flying for 1 1/2 to 2 hours. She never saw or heard him fly over the park, and he was not seen over the family house. The pilot's wife reported the pilot as missing and an ALNOT was issued at 2040. The Ventura County Sheriff located the wreckage at 0300 on October 5, 1998.
RHCI INVESTIGATIVE FINDINGS
RHCI was told that the pilot had recently completed his helicopter training, and at the time of the accident had flown his Mini-500 for 33 hours. His total helicopter time was less than 100 hours. It was reported that the pilot was flying through a canyon in Southern California during gusty conditions. Upon investigating the crash, it was found that all controls were intact, gas and oil were in the tanks, carburetors and engine were running and had no signs of seizure. It is suspected that the gusty conditions blowing over the canyon walls caused the low-time pilot to over control the aircraft, causing the accident.
(23) NTSB Identification: MIA99LA017
Accident occurred Oct-26-98 at Hickory, NC
Aircraft: Reinhold Revolution Mini-500, registration: N500GQ
Injuries: 1 Uninjured
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On October 26, 1998, about 1615 eastern standard time, a Reinhold Revolution Mini 500, N500GQ, registered to an individual, made a hard landing following loss of engine power near Hickory, North Carolina, while on a Title 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The helicopter received substantial damage and the airline transport-rated pilot was not injured. The flight originated from Hickory, North Carolina, the same day, about 1600. The pilot stated that the engine lost power do to a seized rear cylinder. While making a forced landing in a field, the helicopter touched down on uneven terrain and the main rotor blades contacted the tail boom and ground.
RHCI INVESTIGATIVE FINDINGS
The engine was not taken apart to determine the reason why it quit, therefore, engine failure is undetermined. It is known that shortly before this accident, this engine had failed earlier. It was then sent to a Rotax overhaul facility, and found to have a hole burnt in the pistons, due to pre-detonation from low octane fuel. It is believed that the pilot obtained fuel from the same source as before, causing the second engine failure.
(24) NTSB Identification: CHI99LA026
Accident occurred Nov-06-98 at Clinton, MN
Aircraft: Tomschin Mini-500, registration: N316AZ
Injuries: 1 Uninjured
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On November 6, 1998, at 0923 central standard time (cst), a Tomschin Mini 500, N316AZ, piloted by a non-certificated individual, sustained substantial damage when while in cruise flight, the helicopter struck a power line. The helicopter subsequently impacted into a farm field, 4 miles east of Clinton, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under 14 CFR Part 91. No flight plan was on file. The individual operating the helicopter at the time of the accident reported no injuries.
RHCI INVESTIGATIVE FINDINGS
Pilot was performing flight testing for forward balance. He was flying about 70 mph in a hazy overcast. He flew into a power line which contacted the aircraft on the mast, between the main blades and turtle deck. Pilot was able to stay in control until he was about 4 feet above the ground and 500 feet from the contact point. Aircraft landed on the skids and sustained blade and tail boom damage.
(25) NTSB Identification: IAD99FA023
Accident occurred Nov-29-98 At Midland, VA
Aircraft: Armbruster Mini-500, registration: N500GH
Injuries: 1 Fatal
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
On November 29, 1998, about 1515 eastern standard time, a homebuilt Mini 500, N500GH, was destroyed during a collision with trees near Midland, Virginia. The certificated private pilot/owner/builder was fatally injured. Visual meteorological conditions prevailed for the local flight that originated from the Manassas Airport (HEF), Manassas, Virginia. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. A family member reported the pilot missing after not returning from his normal 40 to 45 minute flight. The pilot's vehicle remained parked outside his hangar the next morning, and the Federal Aviation Administration issued an Alert Notice. The Civil Air Patrol's search discovered that tower personnel at HEF recorded the helicopter taking off at 1400. Witnesses stated that they saw the helicopter near Leesburg Airport, Leesburg, Virginia, about 1430, and near Nokesville, Virginia, about 1500, on November 29th. The helicopter was located on December 2, 1998, about 1530, in a wooded area approximately 1/4 mile north/northeast of the Warrenton-Fauquier Airport, Warrenton, Virginia. A survey of the debris field discovered that the initial impact point was the top of a 50-foot tall tree. Tree limbs, measuring 4 to 6 inches in diameter, were cut horizontally and found near the base of the tree. One of the helicopter's rotors was lying on the ground near the tree; the other was snagged on a fracture tree limb about 30 feet above the ground. The main wreckage was lying on its left side between two trees 5 feet apart, and about 35 feet south of the initial impact point. All major components of the helicopter were found at the accident scene. Examination of the flight controls revealed continuity at the time of impact. The engine logbook indicated that in August 1998, at 200.4 hours on the Hobbs meter, the owner replaced both pistons, rings, wrist pins, rod bearings, thermostat, and head o-rings. The Hobbs meter in the wreckage read 218.7 hours. Inspection of the engine revealed two different types of spark plugs were utilized, one of each type in the two cylinders. The spark plugs were wired such that one magneto fired one type of spark plug. Rotation of the crank shaft revealed 4 point scuffing on the cylinder and the Power Take-Off (PTO) piston.
RHCI INVESTIGATIVE FINDINGS
The pilot had installed his Mini-500 “Power Enhancement Package” (PEP), and against RHCI’s severe warnings, chose not to use the provided jet package containing a 2.76 needle jet. Instead he installed a 2.78 needle jet which meant that he needed a 155 main jet to achieve the proper EGT in hover. RHCI informed the pilot that the engine would seize with this small main jet, when at high-power settings it could not supply sufficient fuel to the engine, causing it to heat and seize. The main jet should have been a 165 or 170. Also, he had erroneously set the needle in the third position on the cylinder that seized; the other was correct in the fourth position. He was flying over a forest when the engine seized, and autorotated into a 50-foot tall tree. The impact broke the mast and the aircraft fell and landed upside down on the ground.
Unreported Accidents
The following is a summary of unreported accidents and incidents not only in the U.S., but also in foreign countries. These accidents were reported to RHCI by the pilots, witnesses, and friends, but not to the NTSB, FAA, or the legal authorities in each respective country. Therefore, in order to protect the privacy of those involved, RHCI is only providing a description of the events.
Report 1
Conditions Day
Wind Unknown
Temperature 85 deg. F
Elevation 300 ft
Pilot stated that he was demonstrating the aircraft for someone. He had been flying several traffic patterns and had come to a 10 ft. hover. He suddenly lost tail rotor control. The aircraft hit the ground hard while still spinning to the right. One skid collapsed and the aircraft rolled onto its side. The aircraft sustained typical roll over damage. Pilot received no injuries.
Pilot had reinstalled the tail rotor assembly after trailering the aircraft from Oshkosh. He forgot to tighten the jam nut that secures the tail rotor push pull control cable to the tail rotor gear box mounting plate. When the jam nut finally worked its way off, tail rotor control was lost.
Report 2
Conditions Day
Wind Unknown
Temperature Unknown
Elevation Unknown
The designated pilot for this aircraft failed to make sure there was enough fuel before taking off. After flying for a while, pilot realized he was out of gas and was forced to make an emergency landing. Pilot failed to autorotate successfully, and therefore, aircraft sustained typical rollover damage. Pilot received no injuries.
Report 3
Conditions Day
Wind Gusting to 20-25 mph
Temperature 80-90 deg. F
Elevation 200 ft
There was a witness to the incident. The witness stated that they were doing track and balance. The pilot was hovering the aircraft and the witness was working the balance equipment. The witness said that the aircraft started to oscillate from side to side a couple of times and then rolled over. The aircraft actually sustained less than typical damage. Probable cause of the incident is that the pilot was hovering the aircraft in winds that exceeded his experience level. The aircraft has now been repaired and is again flying. The pilot had accumulated 50+ helicopter hours and received no injuries.
Report 4
Conditions Day
Wind Unknown
Temperature Unknown
Elevation Unknown
Pilot stated that he was returning to the airport and was on a long final when he started to lose rotor RPM and could not recover. The aircraft hit the ground short of the airport at an estimated 20-30 mph. The aircraft rolled three times and broke into several pieces. The aircraft received heavy damage as would be expected. Pilot received no injuries.
Pilot tried to blame the transmission for the loss of rotor RPM. The transmission was shipped to RHCI and no damage other than crash related damage could be found. Further conversations with the pilot indicated that he let his rotor RPM get low and panicked. He said that he applied full throttle but the RPM would not recover. He could not remember ever lowering the collective. More than likely, he saw the ground rushing up at him and raised the collective.
Report 5
Conditions Day
Wind Unknown
Temperature Unknown
Elevation Unknown
The details of this accident are a little sketchy. We have heard two different stories. One, that the controls jammed, and the other that the pilot lost rotor RPM and could not recover. We may never know the truth. The aircraft did land hard and roll over, sustaining typical rollover damage. The pilot was a low-time pilot and received no injuries.
Report 6
Conditions Day
Wind Unknown
Temperature 85 deg. F
Elevation 200 ft
The second-hand word from a spectator is that the pilot was on take off and let his RPM get low and could not recover. He landed hard, collapsing a skid and the aircraft rolled onto its side. Aircraft suffered typical rollover damage. The pilot had accumulated 59 helicopter hours and received no injuries.
Report 7
Conditions Day
Wind Unknown
Temperature Unknown
Elevation 1000 ft
Pilot stated the aircraft had approximately five hours of flight time. The pilot was practicing slide on landing from a hover to the grass beside the runway. One of the skids got caught on an aircraft tie down that was hidden in the grass. The aircraft tipped forward and the main rotor blades contacted with the ground. The aircraft came to rest on its left side. The aircraft sustained typical rollover damage. The pilot received no injuries.
Report 8
Conditions Day
Wind 8 to 12 mph
Temperature 80 deg. F
Elevation 300 ft
The pilot stated that he departed from a local gas station after refueling. He saw power lines in his departure path and decided to do a 180 degree turn. In doing so, he turned downwind and experienced settling with power from about 20 feet and failed to recover properly. On impact the helicopter’s right front leg bent enough for the main blades to strike the ground. The aircraft did not roll over and no injuries occurred.
Report 9
Conditions Day
Wind 25 to 35 mph
Temperature 75 deg F
Elevation 142 ft
The low time pilot had just hovered his helicopter onto a trailer with no incident. As the engine and blades wound down, a gust of wind struck the ship from the side and blew it off the trailer. The aircraft sustained typical rollover damage. No injuries occurred.
Report 10
Conditions Day
Wind Unknown
Temperature Unkown
Elevation Unknown
The pilot stated that while in cruise flight at about 300 feet above rough terrain the engine suffered a "partial" power loss. (There is no such thing as "partial" power loss in a piston engine, and therefore, RHCI feels that the pilot allowed the rotors to lose RPM). The pilot spent some time trying to recover power before setting up for an autorotation. He made a 180 degree turn on the way down. He flared early and ran out of rotor RPM at about 15 feet above the ground. The machine landed very hard on sloping ground and then rolled over. The aircraft sustained typical rollover damage. No injuries occurred.
Report 11
Conditions Day
Wind Light
Temperature Unknown
Elevation Unknown
The pilot had just completed his Mini-500. While he was hovering the helicopter for the first time to break in the engine, he drifted off the tarmac onto a grassy area. One skid caught a mound of grass that was protruding up. The helicopter experienced dynamic rollover and sustained typical rollover damage. No injuries occurred.
Report 12
Conditions Day
Wind Unknown
Temperature Unknown
Elevation Unknown
While practicing autorotations, the low-time pilot inadvertently let the rotor RPM wind down at the bottom end of the auto. There was not enough time to regain RPM before touchdown. The aircraft impacted then rolled over. The aircraft sustained typical rollover damage. No injuries occurred.
Report 13
Conditions Day
Wind 10 mph
Temperature 80 deg. F
Elevation -11 ft
The 50+ hours helicopter pilot stated that after fueling the aircraft, he departed, and then immediately turned 90 degrees left into a crosswind for a two-hour trip. Just before he reached translational lift at a height of about four feet, he let the rotor RPM wind down to where he was behind the power curve and starting to lose lift. He thought about doing a slide-on landing, but decided to do a quick stop instead. At that point he did not have enough RPM to successfully execute a quick stop. The aircraft slammed down bending the right skids and then rolled over. No injuries occurred.
Report 14
Conditions Day
Wind 3 to 5 mph
Temperature 80 deg. F
Elevation Unknown
On approach the low-time pilot let the rotor RPM wind down to the bottom of the yellow. On landing, the helicopter impacted hard enough to bend the landing gear causing the aircraft to roll over. The aircraft sustained typical rollover damage. No injuries occurred.
Report 15
Conditions Day
Wind 20 mph
Temperature 59 deg F
Elevation 2000 ft
The low-time pilot reported he was in very slow flight down wind at about 30 feet when he let the rotor RPM deteriorate. He lowered the collective for an autorotation, then misjudged the time to raise the collective. The aircraft impacted the ground hard enough to bend the legs and then rolled over. The aircraft sustained typical rollover damage. No injuries occurred.
Report 16
Conditions Day
Wind Unknown
Temperature Unknown
Elevation Unknown
The pilot decided to go flying one afternoon, but misplaced his ground wheels and could not remove the aircraft from the garage. He thought he could fly it out, without harming anything. As the helicopter reached the door, the down wash pulled the door down on top of the rotors. No pilot injuries occurred, but the helicopter sustained typical garage door damage. (There have been more than five different stories about this accident, and therefore, RHCI feels that the truth is not completely known.)
Other Accidents:
1) Pilot landed in a field with several other Mini-500s coming in behind for landing. Pilot got out of his aircraft while engine was running and blades were turning, and did not tighten the collective friction. He was motioning to the others where to land, and much to the pilot’s surprise, the aircraft took off by itself, and crash. It is recommended that any aircraft never be unattended when the engine is running.
2) Builder failed to change the center of gravity of the aircraft after a much heavier pilot finished flying. When he picked the aircraft up to a hover, the tail rocked back and the tail rotor struck the ground. Minor damage to one tail rotor blade.
3) Builder failed to remove the packing material from inside the tail boom after trailering the aircraft. While in a hover, the packing material became entangled in the tail rotor drive shaft and severed the drive shaft. The aircraft landed hard and bent the landing gear and tail boom supports.
Non-Flight Related
The following were incidents non-flight related, and they have only be included to provide you with helpful information as to what to watch for when you are on the ground and not flying your aircraft:
1) The pilot reported that while trailering his Mini-500 home one evening, his car collided with a large deer. The deer flew over the top of the car and impacted the front cabin section of the Mini-500, causing extensive damage.
2) Builder claimed that he was cleaning the engine compartment with a flammable solvent. He then claimed that he dropped a screwdriver into the engine compartment, and then went to the house for something. He said he then heard the electric starter of the aircraft making noise, and then saw flames coming from the aircraft. The customer claimed that the screwdriver made contact with a solonoid causing sparks and the electric starter to turn, and the aircraft was destroyed by fire. It is noted that the aircraft was fully insured, and the customer had been advertising it for sale.
3) Pilot reported that he landed and exited the cockpit and was waiting for a friend. At the same time, a Piper Warrior Pa 28 was parking, and its right wing collided into the left side of the Mini-500. The Piper's wing, weighing about 550 pounds with a fuel tank, knocked the Mini-500 four feet from where it was parked. The only damage found in the Mini-500 was a dent above the collective side in the main cockpit structure side wall and between the two left front door hinges. The Piper Pa 28's right wing was a total loss.
End of report.
