Accident Germany

[PTKay]

German only:

http://www.mittelbayerische.de/SID_9a7866e3afd391d57b7572f87b2c916f/nachrichten/polizeimeldungen/polizeiuereg/meldung.shtml?rubrik=afp&id=338266

Translation:

Pilot dies with crash of light aircraft SCHÖNBERG, LKR. TRAUNSTEIN.. At the private airfield SCHÖNBERG near Trostberg fell on Thursday, 15.03.07, from an unsettled cause a light aircraft. The 46-year old pilot died thereby. At 15 o'clock started the man from the district Rosenheim with its two-seat so-called autogyro on the small airfield of a flier association. According to first testimonies the aircraft fell briefly after the start from approximately 50 meters height nearly perpendicularly into the depth. Only the machine in an adjacent field broke open and smashed few meters after the end of the airfield thereby perfectly. The arriving aids of the BRK and the emergency surgeon could not help the pilot any longer. It might have immediately been dead.

Sorry, Babel...

[PTKay]

Another link:

http://www.chiemgau-online.de/lokalnachrichten/tt_text.php?id=13493

Looks like MT-03...

http://www.chiemgau-online.de/lokalnachrichten/bild.php?bild_id=13493&bild_no=0

The pilot bought, reports the autogyro only approximately one month ago eye-witness Werner Frister, which operates a flight school at the airfield lain between comfort mountain and Emertsham for three years: "it was perhaps its second or third flight." The man from the district Rosenheim, which had flight experience with ultralight aircraft according to Frister already and was in the possession of the necessary licence, had the Gyrocopter in one resounds in beautiful mountain stored. Against 15 o'clock it started, and the Gyrocopter flew upward according to police and testimonies about 30 to 50 meters, before he leaned to the rear, fell perpendicularly and about two meters beside the airfield area in a field smashed

[enewbold]

The rest of the story translates to this:

----------------------

Of the two-seat open autogyro, costing, according to Werner Frister, around 50000 euro, only rubble remained. The kriminalpolizei, a flight accident of editor of the police inspection Comfort Mountain and two consultants of the Federal Office for Flight Accident Investigations took up immediately the determinations, in order to find course of events and a cause out of the crash. A flight error, a technical defect, or also health problems - these three reasons would be applicable in principle, said a speaker for the police.

The Schnaitseer flight instructor Werner Frister, which had already given instruction in conventional closed ultralight aircraft to the 46 year old Jaehrigen, was a witness to the misfortune. "As it was, it looked like a possible a technical defect at the control, because on his part a pilot would never set to so a looping to the rear."

----------------------

Another very sad loss to the world-wide gyro community. My condolences to the pilot's family.

Ed Newbold

[twistair]

There is some more information in German language at http://www.ebnetluftsport.com/index.php?id=aktuelles0

(can be translated with Babelfish.altavista.com )

[iconnary]

My German is rusty at best, but here are the relevant details from that last article :

===

A note from the manufacturer.

According to eyewitnesses the crash occurred from a height of 50m immediately after flying past at 10m followed by a rapid climb.

Claudius (the accident pilot) had been tinkering with the machine directly before the flight. He had taken apart and reassembled the entire control system after attempting to repair a stuck PTT switch from the previous week.

The ultimate cause of the accident will be revealed by the investigators.

I'm writing this message for two reasons.

First I want to quell any unfounded speculation.

Secondly I want to encourage everyone to be responsible in their operation of their gyros. This includes a 100-hour inspection of your machine, as well as refresher flight instruction after winter break.

Further information regarding Claudius - ignoring the advice of his flight school, he did not have his license and had not completed his flight instruction before flying his machine. (It's not clear to me if this was the case when the accident occurred, or at some previous time - Iven)

====

[twistair]

I received a bunch of detailed photos from a crash site - don't know if it is correct to post them here. If not - let me know I'll remove'em.

Fly safe,

[PTKay]

According to eyewitnesses the crash occurred from a height of 50m immediately after flying past at 10m followed by a rapid climb.



Bunt-over or rotor flap on top of climb at 0 G ????



Further information regarding Claudius - ignoring the advice of his flight school, he did not have his license and had not completed his flight instruction before flying his machine.


Why must it happen all around the world...
No training, no license...

:(

[EI-GYRO]

Looks like SOME training, no licence. A common feature of fatals.

The recent El Mirage accident is more typical of a NO training, no licence
event. Not usually fatal. Hadnt learned enough to get high enough to kill
himself.

[jos]

Given the heavy deformation on the hub bar rotor rpm was not the cause.
Probably during ground struck a blade got ripped of.
No damage on the vertical surfaces on the tail points also not directly in rotor rpm loss.
So what got the machine on the ground? Control loss? Seems to have hit on the nose.

JOS

[Mark Sanders]

My German is rusty at best, but here are the relevant details from that last article :

===

A note from the manufacturer.

According to eyewitnesses the crash occurred from a height of 50m immediately after flying past at 10m followed by a rapid climb.

Claudius (the accident pilot) had been tinkering with the machine directly before the flight. He had taken apart and reassembled the entire control system after attempting to repair a stuck PTT switch from the previous week.

The ultimate cause of the accident will be revealed by the investigators.

I'm writing this message for two reasons.

First I want to quell any unfounded speculation.

Secondly I want to encourage everyone to be responsible in their operation of their gyros. This includes a 100-hour inspection of your machine, as well as refresher flight instruction after winter break.

Further information regarding Claudius - ignoring the advice of his flight school, he did not have his license and had not completed his flight instruction before flying his machine. (It's not clear to me if this was the case when the accident occurred, or at some previous time - Iven)

====
He just couldent wait the Bigest thing I learned during flight training was patience and It Is Hard To just exept time going by and not to get exited. Even when you have the training you have to exercise patience. Make sure the weather is withen your limits and take extra time pre flightiing. Look it over slow and through you just might find somthing.

[gyropilot]

the Bigest thing I learned during flight training was patience and It Is Hard To just exept time going by and not to get exited.All it takes is killing yourself once, and you quickly learn LOTS of patience as you relax for all eternity!

John L.

[Friendly]

Looks like SOME training, no licence. A common feature of fatals.

The recent El Mirage accident is more typical of a NO training, no licence
event. Not usually fatal. Hadnt learned enough to get high enough to kill
himself.

Could you direct me to the link of the recent El Mirage accident.

PTKay
If this was a bunt over wouldn't the tail be damaged and the rotors folded downward?

[Doug Riley]

Jos, an aircraft with normal tail surfaces will always impact nose-first if it free-falls a distance. The Lawn Dart principle.

[Vance]

What is a Lawn Dart?

What is the Lawn Dart Priniple?

How does this Principle apply to aircraft?

Thank you, Vance

[enewbold]

What is a Lawn Dart?
What is the Lawn Dart Priniple?
How does this Principle apply to aircraft?
Thank you, VanceLawn darts (also called Jarts or yard darts) is a lawn game for two players or teams. A lawn dart set usually includes four large darts and two targets. The game play and objective are similar to both Horseshoes and Darts. The darts are similar to the ancient Roman plumbata; they are typically 12 inches long with a weighted metal or plastic tip on one end and three plastic fins on a rod at the other end. The darts are intended to be tossed underhand toward a horizontal ground target, where the weighted end hits first and sticks in to the ground. The target is typically a plastic ring, and landing anywhere within the ring is considered a point.

[Doug Riley]

Vance, you may remember Lawn Darts as a game marketed to kids some years ago. The darts were, in fact, objects built much like regular dartboard darts, but several times as big. Very fat arrows, you might say.

Like horseshoes, you tossed them toward a target on a lawn. The noseweight and tail feathers made them track downward, nose-first, to the target, as a bomb dropped from a plane does. The nose had a spike that caused the dart to stick where it fell.

There was a fuss over the safety of these sharp weighted objects when tossed around by children.

The name "Lawn Dart" became aircraft slang for an aircraft that crashes steeply nose-first. Any aircraft with conventional tail feathers will, upon entering free fall, nose in like a Lawn Dart if it has time to get oriented to the airflow.

My point was that for the German gyro to have crashed nose-down, the cause of the fall did not have to be an event that would itself create a nose-down attitude; the gyro can assume such an attitude as result of the subsequent fall if it's high enough.

[Vance]

Thank you Ed.

What is the Lawn Dart Princple?

How does it apply to aircraft?

Thank you, Vance

[Vance]

Thank you Doug.

I had not seen Lawn Darts.

I need to learn to type faster so that things don't cross in the mail.

Thank You, Vance

[ckurz7000]

I am in contact with the manufacturer and some local people on site of the accident. According to them, several eye witnesses report that the gyro was doing a loop and had it about 80% complete when running out of height.

The rebuilt control stick handle was apparently not found to be responsible for the accident. Neither were local weather conditions. Eye witnesses also report that the initial climb did not appear too steep, thereby making a push over accident appear less likely.

It may be hard to believe, but according to this information it is the conclusion of the manufacturer that the pilot actually tried to fly a loop in his gyro!

Mind you, even though it sounds crazy, it is not impossible. Pictures exist showing a gyro fly a successful loop (don't try this at home, gents :-)!

-- Chris.

[Doug Riley]

This accident is remarkably similar to one that occurred in a Magni a couple of years ago. There, too, the pilot apparently attempted a low-level loop and didn't make it.

Loops and rolls are possible in gyros, but are unusually hazardous. Low-level aerobatics are quite hazardous in any aircraft.

[Mike Schallmann]

Not trying to be disrespectful --but IMHO --this might qualify as a stupid or idiotic act-- get the scissors out -- I can feel the pain as the Administrators hit the DELETE button----

[Dave Fairbrass]

Why would a low hours student pilot attempt a loop maneuver? Why even go near this territory, I doubt his instructor ever put him in this situation of unusual attitudes so close to the ground being a low hours pilot.

I honestly can’t believe a low hours guy would attempt such a thing. Would be interesting to know his previous flying experience.

Rule 1 – Gyros are not aerobatic

Regards UK Dave

[Timchick]

.......Rule 1 – Gyros are not aerobatic

Regards UK Dave

Could someone please inform Jim Vanek.

[EI-GYRO]

PTK, the el mirage thread is at http://www.rotaryforum.com/forum/showthread.php?t=12015

[Mark Sanders]

My rotor blades came with a video that shows their gyro's and the guy is doing loops and rolls but not low to the ground and its a small single Im not sure i think its called a vortak or vortex not sure on that nice little gyro but the pilot is a professional at stunts when you come out of a flip you got to know were and whin to straighten out. sorta like doing a back gainer off a diving bord for the first time ouch!

[Fl90]

My congrats to the succesful aerobatics in a gyro. That is not the kind of enjoyment I seek from a gyro. There are plenty of craft around that are more suited for aerobatics. My first attept at aerobatics was a disaster with a total loss of equipment. I truly enjoyed that Toyota. Living through that taught me, "the right tool for the job". I would be amazed at the lack of understanding by this individual, if he really was attempting aerobatics while learning to fly anything.

Phil.

[dragonflyerthom]

My congrats to the successful aerobatics in a gyro.Quote Phil


I just love to do aerobatics in my rc's but not in MY Gyro. Seems there was a failure to communicate there in Germany.

[Ron E]

The allegation of aerobatics could be just a ruse to cover for the true cause which might be embarrasing to a manufacturer. But who could really know the true cause of this so soon after ?

[Friendly]

Why would a low hours student pilot attempt a loop maneuver? Why even go near this territory, I doubt his instructor ever put him in this situation of unusual attitudes so close to the ground being a low hours pilot.

I honestly can’t believe a low hours guy would attempt such a thing. Would be interesting to know his previous flying experience.

Rule 1 – Gyros are not aerobatic

Regards UK Dave

Dave, I agree with you . I don't think a low time pilot would attempt a loop. Maybe a shape turn and landing like their video demostrates.

[Dave Fairbrass]

Jim Vaneck is one talented experienced pilot who spent years practicing manoeuvres leading up to the loop. The down side is the risk for error is zero

For me even getting close to loop territory is an area I don’t want to investigate.

Once in my RAF I gave 3 rides to passengers within the space of a couple of hours. The last passenger weighed the least. Wanting to impress my audience each take off was more spectacular. On the last take off I had 90mph in ground effect instead of easing back the stick and let all the excessive speed levitate the gyro & climb, I pulled the stick back a little to aggressively. In an instant I was heading skywards with no horizon for attitude reference. My initial thoughts were what a stupid **** I was for putting myself & passenger in this situation. Then my training kicked in I stayed with the machine eased back on the power, next thing I was at 500ft with little airspeed & recovered in the normal way.

I now put this down to experience but if I had pushed over it would have been a classic accident.

Perhaps the MT03 pilot had lots of speed in a lightly loaded aircraft & entered a way too steep climb & froze? Any tragic accident is bad news & a total waste of life, I’m sure he has left many grieving friends & relatives. If only he had thought out the consequences of his actions

Just my thoughts - Dave

[Ron Marlett]

I think the loop hypothesis is an attempt to divert attention, possibly perpetuated by uneducated bystanders mistaking a rapid climb as the start of a loop. The scene pictures don't indicate an impact after running out of altitude performing a loop. If you have seen the Sportcopter video or done any aerobatics, the back side of a loop is a dynamic place with a lot of airspeed, peaking at the bottom of the loop. If that craft had had much forward momentum, it would most likley have tumbled on impact. Those pictures indicate to me a near vertical decent with a slight nose low impact, engine pushing mast and structure forward and tailfeathers relatively undamaged with tail support structure bent to the ground. If he had failed at any other portion earlier in a loop, I doubt the craft would have landed upright.

Those pics look like the craft was pulled up into a hover and held behind the power curve untill impact, but I am no expert. If a low time pilot, his brain understanding may have been that back stick = up. When it peaked and started to go down, a beginner, who is way behind the aircraft at this point, may have let his brain take over and do what it knew to be right, which is continue to hold the stick back. Or he may have had a control malfunction that locked the stick to the rear. This of course is pure specualtion on my part based on the 3 pics posted.

RIP

[karlbamforth]

Ron,

I agree, the pics seem to show an aircraft with lots of vertical speed but not much in any other direction.

Just speculation on my part but if he climbed rapidly overdoing it getting it vertical and frightening himself, maybe he was reluctant to lower the nose as this would unload the rotor. I am sure he will have heard that pulling back on the stick would load the rotor and maintain rotor rpm, preventing a bunt. In a matter of seconds he would have started what would appear a loop from the ground.

I find it difficult to accept that anyone would deliberatly attempt to do a loop so low with so little experience. The sort of ppl that crash while doing aeros too low are mostly trained, experience pilots that misjudged things.

[C. Beaty]

On the other hand, a vertical descent at zero airspeed is normally survivable. I have some first hand experience at that.

But I agree the loop hypothesis is silly.

[bpearson]

Are there any contributors on these forums that know the workings of the German accident board ? The Magni crash that was on here over a year ago happened I think in Germany and no news.

The accident of MT-03 where the pilot survived has still not been reported on. Maybe the survivor cannot recolect anything about it. In the UK it can take forever before we get the AAIB report.

[Harry_S.]

You might say I survived a vertical descent from about 30-40 ft. with a DEAD engine and very little rrpm.

Only got a small scratch on my lower leg. Lucky...you bet. Hurt pride and hurt pocketbook, tho.


Cheers :)

[Udi]

This accident reminds me of Alan Coat's accident in a GyroBee. The most plausible explanation to Alan's accident, in my opinion, was that he lost power with a nose-high climbing attitude, then he lost airspeed very quickly and, as a new pilot, he jammed the stick forward to regain airspeed. This brought him to a very steep nose-down attitude, which he was not able to recover from given available altitude.

The way this MT03 pod is crumpled tells me the gyro hit the ground at a very steep nose-down attitude - not necessarily high speed.

Udi

[bpearson]

I would have thought after 15 hours the word AIRSPEED would still be ringing in his ears.

[ckurz7000]

I agree that the notion of a beginner intentionally entering a loop is a bit hard to swallow. He might have done a climb that was steep enough to scare him into believing the shorter way was to finish the loop. He also might have frozen on the stick. Apparently, though, witnesses saw him hitting terra firma with 80% of the loop finished. That'd be shortly after the vertical descent portion, with the nose pointing down steeply and the airspeed not yet at its max.

The gyro being registered as an UL, German authorities are not required to investigate (but may do so if they choose).

Just for the records: for FW ppl's converting to gyros the minimum training requirement in Germany is 25 hours. For a pedestrian they are higher, though I don't know how high.

-- Chris.

[C. Beaty]

Chris, I don’t know the roll axis moment of inertia of an MT 03 but steep nose up attitudes during full throttle climb out can reduce rotor thrust sufficiently to allow engine torque to snap the machine inverted and create something resembling a loop.

Perhaps the rough equivalent of a departure stall in a FW.

[Hognose]

This accident seems to resemble the Alan Coates and Tom Monard mishaps in the USA in its dynamics. Especially the Monard RAF mishap -- he was seen to zoom-climb, then descend vertically to impact. Something eerily similar seems to have befallen Claudius.

I discount talk of an intentional loop. According to Otmar Birkner, Claudius was at 10m altitude before zooming to 50 -- I would think even the rudest of beginners would know that this is not the altitude range where one explores aerobatics.

Flying is energy management. A zoom climb lets you convert forward (and stored rotor-inertia) energy into energy stored in the form of altitude. However, you must discontinue the zoom while you still retain enough energy to maintain straight and level flight; or you will be descending on the backside of the power curve, and whether you live to take the benefit of the lesson hinges on just how high you are at apogee and how quickly you can turn that energy into RRPM and forward flight.

Because your absolute altitude at apogee and the amount of time it takes you to freefall that distance (from 50m, under four seconds assuming no lift, which is an unreasonable assumption but simplifies the arithmetic) is all you have left to recover to level flight.

cheers

-=K=-

[Gyro_Kai]

I can only follow the jargon partially, but here is what I experienced (still in training):

During the climbout I pulled the pneumatic trim which is like slowly tightening a spring that pulls the rotor backwards. Due to distraction by gales I forgot to let go the trim, so that finally I had a strong spring pulling back the stick. It can be overcome by pushing hard, but it is quite weird if you do that for the first time. Luckily my instructor sat in the back telling me what to do and stopping the stick from going back too far before I reacted.

The unfortunate pilot here had left instruction early, probably never made this experience before.

Kai.

[Aussie_Paul]

Can anyone tell me how the pneumatic trim works on the MT03? There does not seem to be a trim spring involved.

Aussie Paul. :)

[greeny]

.. Just for the records: for FW ppl's converting to gyros the minimum training requirement in Germany is 25 hours. For a pedestrian they are higher, though I don't know how high ..
For PPL- or UL-pilots, its 25 hours, minimum 5 of them solo.
For newbies, it's 30 hours, at least 10 of them dual.

.. The gyro being registered as an UL, German authorities are not required to investigate (but may do so if they choose) ..
These investigations are performed by the DAeC (Deutscher Aeroclub), not the LBA (the equivalent of the FAA). If ever there are any results, they seem to be kept as a state secret. I contacted them and tried to find out about the Magni accident (Mr. Glanzmann) - to no avail. Didn't even bother to call me back although promised several times ..

.. Apparently, though, witnesses saw him hitting terra firma with 80% of the loop finished ..
With due respect to all who contibuted an opinion here, to suppose that anyone wanted to do acrobatics during a climbout after the start is - well - rather far feched. He was a beginner, yes, but had soloed before.
Eye witnesses usually are not worth to be asked. They do not tell what has happened but they interprete what they think they did see.
Now, probably, they were not pilots. And even if, they most likely hadn't seen a gyro before. So, how would they know what the pilot was doing or intending? From what angel did they see the gyro turn - or 'loop'?

The most likely cause is the equivalent of a stall after take off: getting behind the power curve and freeze on the stick instead of gaining speed. A typical beginner's reaction.

Peter

[gyroplanes]

Rule 1 – Gyros are not aerobatic

Regards UK Dave

And tell Johny Miller as well (and the guy in Florida that used to do barrell rolls)

GYROS CAN DO AEROBATICS, but they are probably THE most unforgiving aircraft to do them in.

[Ron Marlett]

Can anyone tell me how the pneumatic trim works on the MT03? There does not seem to be a trim spring involved.

Aussie Paul. :)

Paul
From the pics I have seen of the MT-03 rotorhead, I would guess that the air in the pneumatic cylinder IS the spring. The cylinder appears to be in tension from the back side of the mast up to the rotorhead, probably with a heim joint at the end of the rod to allow the head unrestricted roll movement. By varying the pressure in the rod end of the cylinder, you change the air springs tension holding force. The force applied is a factor of the piston surface area X PSI and the rate is a factor of the cylinder length. By carefully choosing the cylinder size and limiting the maximum air pressure available to be applied to the spring/cylinder, you can control the maximum force available out of the air spring to keep it within the limits of the pilot to overcome with the control stick.

[Gyro_Kai]

Paul
From the pics I have seen of the MT-03 rotorhead, I would guess that the air in the pneumatic cylinder IS the spring. The cylinder appears to be in tension from the back side of the mast up to the rotorhead, probably with a heim joint at the end of the rod to allow the head unrestricted roll movement. By varying the pressure in the rod end of the cylinder, you change the air springs tension holding force. The force applied is a factor of the piston surface area X PSI and the rate is a factor of the cylinder length. By carefully choosing the cylinder size and limiting the maximum air pressure available to be applied to the spring/cylinder, you can control the maximum force available out of the air spring to keep it within the limits of the pilot to overcome with the control stick.

You are absolutely correct in every detail. Very good eyes, Ron! ;)
The pressure to overcome the trim is maybe 5 kg as opposed to a normal steering pressure of 50grams.

Kai.

[gyrogreg]

Just a thought:

This accident, and the one in the Magni in Switzerland (German pilot?) look an awful lot like inadequate height-velocity to avoid hitting the ground. Such an accident would likely hit the ground in a nose-low attitude without a lot of forward speed.

Such accidents can come from not properly respecting the height-velocity curve ("Dead Man's curve"). Tyoically the height-velocity curve defines the combination of height and velocity required to recover to a safe landing IF the engine quits.

However, inadequate height-velocity can lead to ground impact even if the engine is running. I half-way experienced this same situation a student put me in once (in a Magni). A low level rapid zoom to a nose-high, below the power curve airspeed, might cause force or excite the pilot to rapidly lower the nose to convert their height into enough velocity to pull out before ground contact. Many pilots apply the analogy of recover from the same situation in a FW - where you don't have rotor RPM to affect the regaining of flying airspeed. In a FW, the energy exchange from height to velocity is direct. With a gyroplane, the rotor gets into the energy exchange and mucks up the intuitive perspective.

In a gyro, the nose-down pitch input (to recover from a low and slow and nose-high attitude) can severely slow the rotor. This slow rotor requires some altitude loss to simply regain that RRPM - the result is initially you drop like a rock. The rotor, if it is not already in precession stall or severe flapping from the low RRPM, will be at a poor RRPM to quickly regain full flying RRPM once it is presented with full relative wind again - in the nose-low dive to the ground. Again, the result is a rapid altitude loss - much more so than intuition of FW recovery would lead you to expect. in otherwords, what looks like enough altitude to recover, in a gyro might not be!

I've done this often at safer, higher altitudes. But, my scary experience with this was when a student (a helo commercial pilot!?!), took off with a steepwhy not to be doing this!) - and then he cut the power at about 50 -100 ft. I immediately went full power as I lowered the nose to regain airspeed - but, by then we were deep below the power curve. The predictable rapid loss of altitude occurred, and I had just enough RRPM and airspeed to level the nose for a hard flat landing. (I washed that student out at that point - and had to repair my prop!) But, I could easily see the same fatal wreckage results as on this accident - and on the Magni accident a few years ago.

This does make me wonder if all gyro pilots are getting adequate instruction on the height-velocity curve. This is something that a lot of transitioned FW instructors might not even consider. I would not recommend operation within the height-velocity curve at any time - the engine could quit. But, steep nose-high climbs that decay airspeed below the power curve within the height-velocity curve should be especially avoided, because recovery from these is also very quiestionable - even if the engine continues to run. The rotor exagerates the needed altitude to regain flying RRPM - more than just getting airspeed back!

- Greg Gremminger

[gyro-3xio]

Greg,

Would you happen to have a simple graph of a height-velocity curve for us to look at?

I'm just trying to picture this.

Jim.

[karlbamforth]

Greg,

That's kind of what I was getting at but put forward the possibility that a low time pilot might be reluctant to lower the nose knowing it would reduce rotor RPM. The alternative being to freeze, or continue pulling to maintain a load on the rotor. Of course either way the situation would be getting worse very quickly.

[Doug Riley]

Karl, running out of altitude and airspeed at the same time is bad news -- but given the choice, I'd rather pancake in from a vertical descent than arrive nose low at 60 mph. Frontal crashes are not a pusher aircraft's forte.

Greg's advice is excellent. The lag in the gyro's ability to pull out is eye-opening; there's a period of freefall that amounts to helplessness. A heavy rotor will give you more "hang time," but you'll pay for it at the bottom with more lag before recovery.

If you must do a zoom climb (after you get some experience), bank at the top of it before you run out of airspeed, to rev up the rotor.

[Harry_S.]

This does make me wonder if all gyro pilots are getting adequate instruction on the height-velocity curve. This is something that a lot of transitioned FW instructors might not even consider. I would not recommend operation within the height-velocity curve at any time - the engine could quit. But, steep nose-high climbs that decay airspeed below the power curve within the height-velocity curve should be especially avoided, because recovery from these is also very quiestionable - even if the engine continues to run. The rotor exagerates the needed altitude to regain flying RRPM - more than just getting airspeed back!





A good salient point, Greg.

I would wonder if some newbies even heard of the Height-Velocity Curve.


Cheers

[Doug Riley]

It's in the FAA Rotorcraft Flying Handbook, which is a must-read for every gyro pilot.

[karlbamforth]

I agree completely Doug, was just guessing at why a zoom climb turned into an apparent loop and crash as seen by the witnesses.
A reluctance to push the nose down or an attempt to pull the machine into a steeply banked turn could appear to be a failed attempt at a loop from certain angles.

[C. Beaty]

I was once having a slow flight contest with Van Houten and being a dammed fool, ran out of gas; I suppose at 15 mph and 20 ft. My old Bensen with oxcart suspension thumped in pretty hard but nothing broke.

Slow flight is much better on a nearly empty fuel tank.

[Doug Riley]

Was it Doug O'Connor who augered in flat after his rudder locked up during a vertical-descent pirouette from altitude? His Snobird was demolished but he hobbled away with cracked vertebrae. One of our more tech-savvy Forum posters did the same thing in a Dominator and was not hurt at all, just mad at himself.

A 1200 feet/minute vertical descent is only 20 ft./sec., or 13.6 mph. That's much better than a frontal crash at 60 or better -- and there's more crushable structure under you than in front of you in a pusher gyro.

[gyrogreg]

Greg,

Would you happen to have a simple graph of a height-velocity curve for us to look at?

I'm just trying to picture this.

Jim.

Jim, attached is a page from the Magni M16 Flight Manual. As Doug suggests, this whole subject is explained in the Rotorcraft Flying Manual (FAA-H-8083-21) - available from on-line bookstores or downloadable from the FAA. Anyone flying gyros should be familiar with the gyroplane sections of this manual! (It actually has decent introduction to gyroplane stability issues as well - if done so in a PC manner!)

The height velocity curve is similar to the same for helicopters - but helos usually have a much higher curve - starting around at least 500 ft above the ground. Helicopter pilots often, perhaps more aptly, refer to this as "dead Man's curve" - for obvious reasons! The typical gyroplane H-V curve starts at around 200 ft, but may be lower for lighter gyros with lighter rotors.

This HV curve should be provided by the gyro manufacturer - who has presumably tested to determine the curve. You can determine this - at altitude - by simply checking the altitude loss loss from zero power required to recover enough airspeed for a safe landing. Add a little safety margin to account for the delay upon surprised reaction if the engine suddenly quits. Usually, the curve is a straight line triangle as shown on the attached - so determining the airspeed recovery altituded required from zero airspeed - power off - is what you would need to determine - the top of the triangle at zero airspeed. The "nose" of the triangle would be the minumum airspeed at which the gyro can be landed safely from initial flare height above the ground - 5 ft or so. Note, that there is an area closer to the ground where you are allowed to fly slower - if you are close enough to the ground so that, upon engine failure, you can still make a safe landing. This lower line can usually be assumed to taper to zero height at minimum safe touchdown airspeed - the flare and touchdown sequence in a landing.

This H-V curve is required information in a gyroplane Flight Manual - and a Flight Manual is required to be on board any U.S. Experimental aircraft. This H-V curve is just one of the flight performace properties that are should be determined during the 40 Phase I flight test hours on a newly certificated Experimental gyro.



- Greg Gremminger

[dragonflyerthom]

This is some eye opening info. Some of this is new to me and I bet to a few others. I believe I have discovered some nuggets. A lot of this isn't taught to newbies. I would imagine it would constitute an overload to most newbie as myself. We need a book that show all of the stupid pilot tricks not to do. Thanks to all

[Vance]

When I was training in helicopters the height velocity curve was paramount. I watch helicopters fly in the movies and they take off straight up. We would go from a hover taxi, drop the nose and accelerate to around 70 mils per hour before beginning a climb out. When my instructor would cut the power the reason for this was clear. We would do a quick stop that would trade forward speed for altitude and rotor rpm and then level the ship and set her down.

I feel that the height velocity curve is often ignored in helicopters. I see people hovering at 300 feet AGL or taking off straight up. We had a special procedure for a short take off and it was still not straight up. I haven’t had to read very far in the NTSB reports of helicopter crashes to understand how speed and altitude are your friend.

When I have mentioned the height velocity curve as one of the challenges of a jump take off in a gyroplane, I have, in my opinion, been dismissed as over cautious.

One of the things that I love about gyroplanes is their shrunken height velocity curve.

Thank you Greg for pointing out the potential challenge and limited options when the height velocity curve is ignored.

I know that gyroplane pilots love to show off how fast they can climb by trading forward speed for climb, but I feel that when they get to the top, their energy bucket is empty and their tolerance for the unexpected is diminished. Pushing over with a teeter rotor was discouraged in all of my rotary wing training.

I have had the falling elevator feeling, but always with plenty of altitude. I am grateful for my helicopter training and the respect for the height velocity curve it gave me and I am grateful for my gyroplane instructors and how by the book they were. I am not sure why there seems to be a resistance to the concept.

Thank you, Vance

[C. Beaty]

The deceleration of a gyro in a vertical descent depends upon the stroke of the landing gear.

a = V²/(64*s)

a = deceleration, Gs when landing gear stroke (s) is feet and V (descent velocity) is ft/sec.

For 1200 fpm and a gear stroke of 1 foot, the landing force is 6.25 Gs with optimum spring rate and damping. Most gyro gear will collapse at that level but the pilot should be able to walk away.

A rate of descent of 600 fpm, again with optimized gear, only results in a 1.563 G deceleration.

Soft springs combined with dampers having square law response (resistance = square of velocity) are near optimum.

[JEFF TIPTON]

As a newbie I will take the time to read the Rotorcraft Flying Manual (FAA-H-8083-21).

Any suggestions on the next book a newbie might want to read.

[Doug Riley]

Vance, you're right that the H-V concept is critical to jump takeoff. H-V is simply energy management in a situation where energy inventory and flow are strictly limited in the short run -- and where the short run is the only run of interest!

By overspeeding the rotor, however, we create a fourth source of energy.* This extra inventory and flow move the whole curve down and to the left, in some cases dramatically. If we manage energy properly, we can stay inside the (RRPM-enhanced) H-V curve. A conservative jump takeoff might still involve no ground roll, but would also feature a transition to forward flight before RRPM decays to cruise (or lower!).
__________________
* The other three are the engine's real-time output (but =0 in a deadstick), aircraft height and airspeed.

[barnstorm2]

As a newbie I will take the time to read the Rotorcraft Flying Manual (FAA-H-8083-21).

Any suggestions on the next book a newbie might want to read.

Yes!

Books by Paul Abbot

Homepage: http://www.abbottcompany.com/

The gyroplane flight manual.

Excellent, book. If you get no other Abbot book get this one. Good for beginners through old salts.

How to license a Homebuilt Aircraft.

Fantastic book for anyone building there own aircraft of any kind.

Understanding the Gyroplane by Paul Abbot, ( see www.abbottcompany.com for info ) More detail for the beginning designers and technical fans.

From Autogiro to Gyroplane by Bruce H. Charnov

The first and only history of the autogyro and gyroplane. A must have for any rotorcraft aviation fan. Well written and researched.

A Dream of Flight by Dr. Igor B Bensen

I have yet to read this book. ( see www.abbottcompany.com for info )


Rotorcraft Flying Handbook by the FAA (as mentioned)

and more:


http://www.prachapter34.com/toppage9.htm

http://www.prachapter34.com/libary.htm


.

[Vance]

Thank you Doug,

I mentioned jump take off only because of the response to my concerns. There didn’t seem to be much concern that rotor rpm was decaying and there was little airflow over the control surfaces.

The thought in my helicopter training was that there are three buckets of energy; altitude, forward airspeed and rotor rpm and you could move energy from one bucket to another with different flight maneuvers. It was considered important to not run all three buckets out or be in a position to not perform the flight maneuvers to transfer the energy when one of the buckets was low. Low rotor rpm was to be avoided as a non-recoverable event. The Robinson 44 has a lot more energy storing capability in the rotor that any gyroplane I have flown so I feel that rotor rpm in a gyroplane is a smaller bucket.

I love the way gyroplanes fly and they seem so forgiving of mistakes. I suspect that I feel Thom’s response is typical and it comes after formal training.

My gyroplane training has, in my opinion, been quite good with respect to the height velocity curve, best rate of climb, rotor management, climb out procedures, traffic avoidance procedures, communication and emergency procedures. Not everyone here has had the good fortune I have had and I feel this is a worthwhile subject. Most people here seem to get it, but for those who don’t, the height velocity curve is a trap with unpleasant consequences.


Thank you, Vance

[Udi]

I had a very good FW flight instructor who worked with me on all aspects of emergency procedures. When I started flying gyros I wanted to cover emergency procedures just as well. It's easy to fly a gyro but are we ready to handle an emergency at the worst times during the flight?

When I came to practice with Greg Bradley in the tandem Air Command just before soloing my new single place Air Command, he was surprised that all I wanted to do was practice emergency procedures. At some point Greg told me - I think you are ready for this -- and he pulled out the power 40 ft high right after takeoff (arguably the worst time to have an engine out). He was right - I was ready and the landing was smooth and uneventful.

If your instructor doesn't take enough time to go over emergency procedures in all phases of the flight - ask him to give you more. The instructor is working for you and you should make sure you get the training you need to handle any situation when your instructor is not there with you. Even experienced pilots can benefit from practicing emergency procedures with a flight instructor once in a while.

With regard to pilot protection during a vertical crash I found the following interesting power point presentation (http://155.178.136.36/2004Conference/files/crash/S.Desjardins_Energy_absorption-helicopter_seats.ppt) about seat design in helicopters.

Udi

[bpearson]

I was always concerned about how agressively the nose could be lowered when the engine quit on takeoff. If you have airspeed should'nt be a problem but I remember a case years ago where this happened and the pilot managed to slow the blades enough so there was nothing for the flare. Or so the report at the time said.

I always thought a vertical descent to the ground was not a life threatener in itself if no fire.

[gyro-3xio]

As a newbie, I feel somewhat reluctant to respond here.
(New guy,... stupid question syndrome!!)

First, thanks to Greg and Chuck B. The graph, as they say is worth 1,000 words. Makes a lot of sense. Chuck B, now that is a formula I had to copy into my notes. That makes a lot of sense too.

From this thread, 'my' observation would be:

a) This region that is "inside" the H-V curve would be as equivalent to a stall region on a FW. (in a crude sense)
The airfoil on the rotor is not actully stalling, but will slow down to the point where lift no longer exceeds weight. (and height is not there for recovery.)

b) What else comes to mind here, correct me if I'm wrong with this, a gyro doesnt' stall,.. like a FW does. But,... it has it's own serious characteristic that deserves the same amount of attention as a stall would in a FW.

Is that correct?

Reason why I make point b) is to dismiss this myth from some gyro groups that "gyro planes are much safer than FW because they never stall."
Maybe,.. but 'other' serious factors come into play instead.

Am I still missing the big picture?
Jim.

[Udi]

...From this thread, 'my' observation would be:

a) This region that is "inside" the H-V curve would be as equivalent to a stall region on a FW. (in a crude sense)
The airfoil on the rotor is not actully stalling, but will slow down to the point where lift no longer exceeds weight. (and height is not there for recovery.)

b) What else comes to mind here, correct me if I'm wrong with this, a gyro doesnt' stall,.. like a FW does. But,... it has it's own serious characteristic that deserves the same amount of attention as a stall would in a FW.

Is that correct?...
a. no, b. yes.

The H-V curve represents an area in the flight envelope where the gyro does not have sufficient airspeed to perform a landing flare. The rotor, even inside the "bad" region in the H-V curve is always supporting the weight of the gyro.

A landing flare is when the gyro is converting kinetic energy for additional lift in order to stop descent and usually slow forward speed before touchdown. When the gyro is coming in too slow for landing, it has not enough kinetic energy to trade for lift - so it just flies into the ground without flaring.

Believe it or not, FW airplanes have a similar region in their flight envelope. Come in to land in a plane at the stall airspeed and you cannot flare - but the descent rate of a plane is normally much slower than the descent rate of a gyro or a helicopter in autorotation, so it would sustain less damage.

Many trained and experienced FW pilots are killed every year as a result of stalling and crashing. Flying behind the H-V curve should not cause any deaths as long as the pilot doesn't do something stupid like unloading the rotors and diving into the ground. This is a very very rudimentary error that shows a complete lack of training and experience. Normally gyros are much more forgiving than stalled airplanes.

Udi

[ferranrosello]

Jim, I think there is a big difference between a FW stall and autogyro H/V curve limitation.

In gyro you are able to climb after take off or to descend prior to landing keeping away from the H/V prohibited area. In a fixed wing you cannot avoid the danger of flying at very low heights.

If you have an engine failure immediately after take off you will be in a perfect landing position if you are flying an autogyro properly.

In a single engine FW you will probably crash. Another big difference is that the gyro has always a full control capability which is independent from air speed. An stalled FW cannot be controlled.

The only thing (and this an easy one to comply with) is that you need to maintain a safe speed when flying close to the ground.

A key question is to perform adequate landing an take off profiles. We only should climb after gaining a safe airspeed, and we only should reduce AS at very low level prior to the landing. In this video is shown a safe take off profile.

http://www.youtube.com/watch?v=6ETwMPIhpb4&mode=related&search=

[ckurz7000]

To return to the original topic of this thread:

I just received new information about the fatal gyro accidend in Germany: the pilot did indeed attempt a loop and made it almost all the way around. The gyro crashed onto its wheels, alas at an incredible rate of descent and thereby killing the pilot instantly.

Whether the apparent loop was intentional or not we'll never know, however -- and that's the new bit of information -- an autopsy revealed that the pilot must have been high on marihuana. So far there's no indication that the gyro malfunctioned.

Eye witnesses who were only 30 meters to the side of the crash site report that the pilot did several low passes at 150 km/h. After the last high speed pass he climbed steeply and never eased out of the climb.

-- Chris.

[dragonflyerthom]

Drugs and flying just don't mix. No matter how they are mixed. Thanks Chris for the update.

[Fl90]

Wow!.....I'm speachless/typeless

[Hognose]

Good God in heaven.

Cannabis was found in about 10 fatal mishaps a year in the US, according to a study of accidents in the mid-nineties that is quoted here (http://www.skyaid.org/Skycar/GA_Problems.htm) (I haven't seen the actual study; the site looks like it's promoting the perpetual-vaporware Moller Sky Car).

In connexion with an accident study in 2004 (of a 2002 mishap -- a pilot made all the wrong calls when an engine failed on an island takeoff, killing himself and a planeload of passengers, including children and one-half of a honeymooning couple), the Australians have done some comprehensive literature surveys on impairment caused by cannabis. They also did a comparison study on alcohol... I wasn't surprized that alcohol was a worse problem, but I was surprized at how bad cannabis really is.

I don't use the stuff (I get high on wings and rotors instead!) but the users I have known have mostly turned into passive, listless drones, rather than wild out-of-control barbarians. But the medical literature says it's an extremely bad idea to go flying on it.

Here's a news story on the accident (I know I wrote one for Aero-News but didn't find my story, here's Russ's from AvWeb):
http://www.avweb.com/avwebflash/briefs/186940-1.html

Here's the ATSB's report on the Cherokee accident (gee, I wish our NTSB would [1] put the images in the reports like this, [2] investigate GA accidents this thoroughly, which they only do if there's a celebrity on board now, and [3] hire somebody who can spell.

http://www.atsb.gov.au/publications/investigation_reports/2002/AAIR/pdf/aair200204328_001.pdf

Here's a coroner's inquest into the same mishap. Note on p. 21 (p.23 of the .pdf) the comments on drug use by pilots. They indicate that Mr Morris may not have been "stoned" at the time, the THC was merely in his system from before.
http://jp.justice.qld.gov.au/courts/coroner/findings/hamilton0906.pdf

The cannabis study is here:
http://www.atsb.gov.au/publications/2004/Cannabis_pilot_performance.aspx
One interesting note: "Significantly, the modern dose of cannabis is much more potent than in the past, when the majority of the research was conducted." I just read that in Britain (and maybe elsewhere in Europe?) there is a new crop of weed that is more potent than in the past and it is landing people in drug rehab.

The alcohol study is here:

http://www.atsb.gov.au/publications/2004/Alcohol_and_human_performance.aspx

(These pages lead to abstracts... there you can download the pdfs).

The take-away from both these reports is -- while many people enjoy these common drugs, they impair one's ability to fly more than is commonly thought, and for longer after using them, especially under high-workload or high-stress conditions, than is commonly thought. "Eight hours bottle to throttle" (and I don't know what's the dope equivalent, "eight hours from rolling papers to rolling-for-takeoff?") may not be enough for your judgment to recover from the effects of these things.

Loop at nought feet in a gyroplane. Lord love a duck. Do you guys have any idea how many hours of sweat in aerobatic practice a Jurgis Kairys or Patty Wagstaff has amassed, and how many loops safely conducted at altitude, to attempt this kind of thing? Not to mention that they do it in a purpose-built airplane that is stressed to +12/-12G?

No new accidents, unfortunately. New pilots having the same old accidents.

cheers

-=K=-