Smuz RAF 2000 GTX SE - No Injuries

[WN]

NTSB Identification: SEA05LA044
14 CFR Part 91: General Aviation
Accident occurred Thursday, February 03, 2005 in Puyallup, WA
Aircraft: Smuz RAF 2000 GTX SE, registration: N26AV
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 February 3, 2005, at approximately 1000 Pacific standard time, a Smuz, RAF 2000 GTX SE (Sparrow Hawk), amateur-built gyroplane, N26AV, was substantially damaged when it rolled onto its right side during a hard landing at Pierce County-Thun Field, Puyallup, Washington. The airline transport pilot trainee, the sole occupant in the gyroplane, was not injured. Latah, Inc., was operating the gyrocopter under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the local, instructional-solo flight, that had originated approximately 15 minutes before the accident. No flight plan had been filed.

The pilot said that he had approximately 2,000 hours of flight experience in helicopters, and was a flight instructor for the army. He was adding the gyroplane rating. He had 13 hours of training, and this was his first solo flight. He said that on his third landing, he was performing an autorotation. He said that he flared several feet high, and he added a little power to "smooth out" the touchdown. When the power came in, the engine torque rotated the nose of the gyrocraft to the right. The right main gear hit the ground, and the craft bounced back and fourth on its main landing gear. Subsequently, the gyroplane rolled onto its right side bending its blades, mast, and horizontal and vertical stabilizer.

[chuter]

He said that on his third landing, he was performing an autorotation. :D :D

It's a good thing he was autorotating on that landing......... :p


(I'm laughing at the report, not the pilot's misfortune. Sorry to hear of anyone crashing their machine)

[GyroRon]

Sorry big time to hear about that. That was the machine known as Ruby I think..... Used in the Sparrowhawk flight school up there. $hit happens :(

[Harry_S.]

I hate to hear/read about those reports too, Ron...but I can hear 'em comin'...[FONT=Arial Black]"It had to be the RAF's fault. Poor design."[/FONT
Very little will be said about experience or training in gyros.


.

[Brian Jackson]

I hate to hear/read about those reports too, Ron...but I can hear 'em comin' "It had to be the RAF's fault. Poor design." Very little will be said about experience or training in gyros.
It saddens me too, but I'm thankful nobody was injured. I know a lot of folks like to rag on RAF, but this was clearly not a design fault. It could have happened to anybody. I suppose there's a humorous side to this... I couldn't help but fall out of my chair laughing at the line "he was performing an autorotation." Good thing he lowered the collective in time, eh?

Sorry, I'm not making light of this in any regard. But it does field-demonstrate a lack of understanding of Gyroplane physics on the part of NTSB. Are the reporters just not aware of how they fly? I'm truly curious.

Thanks,
Brian Jackson

[PW_Plack]

Remember this report when you're tempted to get crabby about the hourly cost of flight instruction in gyros, or bash a CFI who won't let students solo in the trainer.

I'm grateful that dual instruction is still available at any price.

And Brian, you're right..."The pilot reported a suden loss of power to the rotor..." :)

[KenSandyEggo]

Harry, it wasn't an RAF anymore. It was a Sparrowhawk conversion, which means it was CLT and had a huge HS. This accident had nothing to do with the type of gyro being flown. It would have happened in just about any one. Is it just my imagination, but do a lot of gyro accidents seemingly involve fixed-wing or helicopter ATPs?

[Chopper Reid]

Harry, it wasn't an RAF anymore. It was a Sparrowhawk conversion, which means it was CLT and had a huge HS. . Is it just my imagination, but do a lot of gyro accidents seemingly involve fixed-wing or helicopter ATPs?

Ken, this has been something I have posted on here and on the Ozz forum and that FW pilots tend not to make good gyro pilots and the more hours they have and being a jet jockey seems to make the situation worse. No doubt over time they may soften their touch. I am a FW pilot and I tended to overcontroll and not have a good touch first off. Their is a lot more "feel" involved in flying gyros !!
Just my opinion.
'

[BSAFER]

While I don't have my gyro yet(SH), nor my training, I'm compiling lists of questions and issues to address with my trainer. Many based on this site. Things like this will certainly be questions on how to handle or what to expect. I don't want to build my craft and go through the training and have something like this happen (although I know things happen). I guess I would expect this type of issue to be covered in training as a norm.

Is there a book (I learn lots from books) that covers the issues so I can be as prepared for training as possible? I see quite a few books on Gyro's sometimes tacked on with Heli's, some get into a few dollars. Appreciate advice.
Brent

[Mayfield]

Good morning all,

I suspect that most of us remember our first solo in type. The ones that started off in fixed wing probably heard something like this from their instructor as he got out of the airplane:

"Ok, show me three good full stop landings. Taxi back to the runway after the first two. Bring the aircraft back to the FBO after your third one. Relax, take it easy. If it does not look or feel right: go around."

Mr. Creech's third (and final) landing approach is analogous to making the third landing, in a first solo flight, a power off approach and landing in a fixed wing aircraft. Our instructor would have had our guts for garters if we had done something like that.

It does not matter how much time the gentleman had in fixed wing aircraft or helicopters. His first solo flight in a gyroplane was not the right time to practice power off landings.

In my opinion, humans react to sensory input based on instinct or reflex. Reflexs are trained responses. This gentleman has 2000 hours in helicopters.

I suspect, that he set up a very nice, stable power off approach. Everything looked good. Then I suspect he started a nice gentle "full down" autorotative flare at about 40 feet. The aircraft began to settle at a high closure rate. I suspect that he did not recognize the high closure rate until he was within 15 feet of the ground, sinking at about 500 feet a minute.

He then probably went to full power. By then he was so far behind the power curve that almost infinite power could not fully arrest the descent.

I suspect that as this situation developed and became a helicopter "full down" in his mind, that he was desperately trying to corollate what was happening to him with 2000 hours of experience in another aircraft type.

I was not there. I am being a Monday morning quarterback. But for you folks getting ready for your first solo: take it easy!

Learning new reflexes takes time. There is no reason to rush it. I apologize if I sound harsh, but this appears to be the case of ADM resulting in the crash of a perfectly good aircraft.

R/S

Jim Mayfield

[Harry_S.]

Yes Ken, I knew it was a convert. I was just making light of any forecasted bashes. I agree with you, as I have mentioned several times in the past...some high time F/W and Helo pilots seem to have a problem with transitioning to gyros. EGO...maybe?!

Back in the 60-70's we had too many incidents and accidents, and a good percentage of them were by the more experienced pilots. Myself, being F/W rated, went into gyros with an open mind. We started a PRA Chapter and built a glider. I had several hundred hours flying the glider before I had the opportunity to buy a MAC powered BM7. I had learned blade control with the towed glider, so the only big problem I had with the BM7 was getting used to the power...but I digressed. I remain adamant on the proper gyro training for anyone...regardless of ones aviation background. 'Nuff said.

Brent:
Your approach to gyros is refreshing. Read all you can...ask questions of everyone, even another student...and obtain instruction from a certificated instructor. Your dreams will be realized. Keep us posted.


Cheers :)

[barnstorm2]

While I don't have my gyro yet(SH), nor my training, I'm compiling lists of questions and issues to address with my trainer. Many based on this site. Things like this will certainly be questions on how to handle or what to expect. I don't want to build my craft and go through the training and have something like this happen (although I know things happen). I guess I would expect this type of issue to be covered in training as a norm.

Is there a book (I learn lots from books) that covers the issues so I can be as prepared for training as possible? I see quite a few books on Gyro's sometimes tacked on with Heli's, some get into a few dollars. Appreciate advice.
Brent

Brent, here are a few books and downloadable reading materials:

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

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

http://www.prachapter34.com/toppage4.htm

[BSAFER]

This website has alot of information. Just passing time mostly waiting for the parts to start showing up!

Thanks for all the info and help!
Brent

[pwendell]

I'm very sorry to hear about 26AV. I had several hours in her and she flew well. I am very glad the pilot was unharmed. It's hard to believe the pilot would attempt a power off on his third solo landing. If I had done that, Terry would have grounded me for life.

What was he thinking?

[ScottTinnesand]

Peter,
Dave Creech will be posting soon about the accident in Ruby.

You said, "It's hard to believe the pilot would attempt a power off on his third solo landing. If I had done that, Terry would have grounded me for life. What was he thinking?"

Being intimately familiar with the accident, I can tell you that he flew the first solo flight exactly as briefed between he and his CFI in Washington. I mention this only to help you understand that your comments, which I didn't take as very constructive, may be misguided.

Dave Creech does visit this forum and will post soon, as I mentioned above. Seeing how I have flown as an instructor with both of you, I feel that I can jump in here to keep things in perspective. My recommendation is to not be too harsh with your public responses to an accident that you know nothing about (yet). Comments like, "What was he thinking?" and "It's hard to believe..." aren't going to do anything except irritate those involved. The response that Jim typed is a well thought-out response from a CFI/DPE's perspective.

Now, before my post becomes non-constructive, let me add that there are many lessons to be learned/re-enforced with this accident. I do feel several errors were made that day and I've already had the luxury of debriefing both the CFI and Dave Creech. Is the first solo the time to practice simulated engine failures? No, I don't think it is, however, the CFI and student did come to that decision. Peter, I think you'll enjoy the post Dave is going to make as he spells-out his thoughts on the accident.

As Terry would say, "Keep smiling". Look for Dave's post soon.

Scott

[Vance]

It certainly sounds like something I would do. I don't always flair at the proper height and the modified RAF I have been flying doesn't go straight when I add power to mitigate my decent rate. I think that people underestimate the effects of the rotor. When my landing is less than perfertct (always) I wonder how close to the edge I came. It has been my experance that when I am in the middle of something with a poor outcome it is very different than trying to imagine it. I do like to point my finger and say that I wouldn't have done that, but I have not found that sort of self delusion productive. Thank you, Vance

[Mayfield]

Thanks Scott,

I look forward to reading David's thoughts on the mishap. He was the closest to the scene and can describe what happened best.

I believe that dispassionate dissection of the decision cycle can help all of us. As you and I were both taught: "A mishap is the last event in a long causal chain."

If the chain can be broken at any point up to impact, the mishap can be averted.

David's willingness to share his (and others) decision cycle may prevent a similar mishap.

Thanks Scott,

Jim

[dwcreech]

Hello all,

I’m the pilot who balled up N26AV (a.k.a. “Ruby”). There are a couple of speculations from the posts above that I would like to address. Hopefully, there are a couple of learning points that can prevent such a similar occurrence.

1. The NTSB report says “on his third landing, he was performing an autorotation.” In MY report I said that on my third landing I was performing a power-off (idle) 180 autorotation. Yes, every landing in a gyro is an autorotation and I am aware of that. Any gyro pilot would have known what I meant, but it was a poor choice of words for the NTSB report. Sorry about that.

2. “… but I can hear ‘em comin’… ‘It had to be the RAFs fault. Poor design.’” I won’t comment on the RAF design here, but as was pointed out, this was a modified RAF with CLT and a large vertical stabilizer. To use a popular phrase, I suppose I could say, “It wasn’t my fault, it wasn’t the RAF’s fault, it was the asphalt.” But in actuality it WAS my fault and I recognize this. Whether it was something unexpected that happened, or poor habit transfer, or a combination of factors may never be known with certainty. I will try to explain what I experienced and hope that we can learn from the mistakes of the past.

3. “Is it just my imagination, but do a lot of gyro accidents seemingly involve fixed-wing or helicopter ATPs?” I doubt that the ATP part has anything to do with it. Sure, there are some negative habit transfers involved and fixed-wing pilots as well as helicopter pilots must be broken of those bad habits (regardless of the rating or certificate held). I had some bad habits early in the training. Here are a couple that I can think of so you CFI types out there can be on the lookout for them:

(a) Helicopter = higher flare. As Jim Mayfield pointed out. I’ve done touchdown autos in a UH-1 (Huey) and, though we don’t practice touchdown autos in the Blackhawk (UH-60), we do get a lot of them in the simulator. Either way, round out or initial flare begins at 75-100 feet… bad ju-ju for an autogyro.
(b) Helicopter = centered cyclic on touchdown. For autos or roll-on landings in the UH-60 Blackhawk, the cyclic MUST be centered when the mains touch down. Otherwise, you risk lopping off the ALQ-144 transmitter (a very expensive infrared countermeasure) or, worse yet, the tail boom. Again, bag ju-ju for an autogyro.
(c) Fixed-wing = very different glide ratio = very different angle of approach to maintain best glide (Max L/D ratio). I had a little trouble at first getting used to the pitch angle on approach.
(d) Fixed-wing = higher flare and longer glide.

4. “His first solo flight in a gyroplane was not the right time to practice power off landings.” Although it may be said in hindsight that my first solo flight was not the right time to conduct a power off landing, I had already demonstrated multiple power off landings – straight in and 180’s – and had become quite good at them. As a matter of fact, I like them better than the normal landings! That being said, I suppose there is some wisdom in holding off on this maneuver a while longer.

5. Okay, now to the nitty-gritty…

I had just demonstrated three good landings to my instructor – one of which was a power-off 180. I was feeling very confident in the aircraft and he decided it was a good time for a solo. We did not have any ballast where we were and so we discussed how the gyro might react differently with 215 lbs less weight in the front. We talked about how the gyro would try to leave the ground sooner, so watch the rotor rpm. We talked about how the rate of climb would be faster and how the rate of descent would be slower (because of the reduced weight). We also talked about the tendency to balloon in the flare – if you get accustomed to the flare with 400 lbs up front, it should be less dramatic with 200 lbs, etc.

My first two solo patterns were great and I thought my landings were some of the best I’d had. On my third landing I killed the throttle abeam the numbers and began an immediate turn to the runway. Scanning runway – airspeed – runway – airspeed – runway – airspeed, everything was working out great. I lined up with the runway and began an initial flare (roundout) that I felt was a couple of feet higher than it should have been. Had I done nothing at that point, I am convinced I would not be posting this message. I would have landed a little harder than I would have liked to, but nothing more. However, I decided to add power to “cushion” the landing. I had done this on a few occasions with my instructor and those landings worked out fine. Looking back on this I think one of the critical factors was the exact point in time that I actually applied the throttle.

There is a brief period in the initial roundout when you try to hold the gyro parallel to (and just a couple of feet off of) the ground. As the kinetic energy in the rotor system dissipates, groundspeed drops rapidly and then you get that proprioceptive feeling of the gyro beginning to “settle.” At that point, about a foot off the ground, is the point of the full cyclic-in-your-chest flare. In my case, instead of being a foot off the ground, I was perhaps 2-3 feet. By the time I applied power I was at about one foot. It was not full throttle – remember, I just wanted to cushion the touchdown – but it may have been more throttle than I needed. At any rate, I did not anticipate the rotation of the cabin about the longitudinal axis when I applied power. This was due, of course, to the torque effect of the prop… something that had probably been dampened by the extra weight in the front when I’d used this technique before.

On this occasion, however, I was taken completely by surprise and the result was that the right main landing gear touched down first. Almost like a basketball, the gyro bounced to the opposite main. I had already applied left cyclic to compensate for the momentary roll of the fuselage to the right (just like on takeoff). This resulted in the left main landing gear touching down even harder than the right. The gyro again bounced to the opposite main landing gear – these were small bounces initially, but grew very rapidly in magnitude. This could be an example of the first lateral PIO in a gyroplane???

Now picture this happening several times, with the gyro essentially “walking” down the runway. Each time this happened the nose was displaced off-center and when it finally came down it was off-center enough to roll the aircraft. The fact that the nose took a while to come down makes me think that I kept the cyclic full aft. However, it is entirely possible that with partial power applied I “relaxed” some of the aft cyclic. This would have only served to compound the problem.

I expect that as more people, like myself, stumble upon this great secret called gyroplanes, there will be large numbers that will either want to own one or fly one. I also expect that if this could happen to me, it could happen to someone else. There are certainly some lessons to be learned here about ballast, power-off landings, etc. Perhaps these are lessons that have been learned before but not adequately addressed or disseminated. Who knows for sure, but it will be forums like this that will help educate. Keep up the good work.

I leave it in the very capable hands of you gyro experts out there to decide what happened and what can best be done to keep it from happening again.

[pwendell]

Scott and Dave,

I truley apologize. I read more into the preliminary report than I should have and jumped to a conclusion before I had all the facts. I should know better. My comments were also not very constructive, as Scott pointed out and would have been better left unwritten in any case. Again, I apologize.

Thank you Dave for sharing your story so that we can all learn from it.

[Mayfield]

I, for one, appreciate you taking the time to post your first hand view.

You were first at the scene so I believe your take on what happened has great credibility.

One of the challenges that has faced every attempt to "legitimize" gyroplanes has been finding suitable training. Randy Coplen, Scott, and a bunch of others are trying to help. Recruiting professional pilots like yourself can only improve the gyro training situation.

We learn from the mistakes/mishaps of others and hopefully from our own survivable mistakes.

You, by the way, are not the first to enter a lateral PIO. Scott Tinnesand and I experienced a roll/yaw coupled PIO in the first ground effect flight of the H6.

The aircraft was fine. The pilot (me) was to blame.

Thanks again for posting David. The more people can know about the chain that led to a mishap the better off we will be.

I hope to see you for your Commercial and CFI ride soon.

R/S

Jim

[Vance]

Thank you David, That was very well written and described everything in a most usefull way.

I am glad you were uninjured.

Do you plan to continue to fly?

It sounds like a frightining experance as you watched controll slip away. I love gyroplanes, but I have yet to have anything but positive experiances so I haven't stood in your shoes. I hope you will continue in the sport and continue to share you knoledge. Thank you, Vance

[gyropilot]

Thanks for taking the time to share your experience with us David. Those who are smart will pay attention and learn, not only their own mistakes, but those of others. I've been where you are and my heart goes out to you and the aircraft owners.

Regarding power-off landings...

Having never flown anything but military helicopters before I took up gyroplanes, the lower flare and faster timing of a power-off landing definitely took some time to get used to. Early in my training I *always* flared too high.

Now that I've gotten accustomed to flying these tiny little aircraft, what's worked well for me... no matter what make / model/ weight of gyro (and your mileage may vary of course)... is a light progressive initial flare at 25-50 feet to "test" the sink rate and gyroplane control response, followed by a final flare at 6" to 12" of whatever magnitude is needed to make a soft touchdown. My initial instructor Scott Malone taught me this technique.

Obviously when in a heavily loaded gyro at a high density altitude, the final flare will have to be quite aggressive and can be a bit of a surprise to someone not expecting it (namely your instructor if not briefed). Someone used to a more aggressive initial flare and a less aggressive final flare might not understand the slightly higher closure rate a few feet above the runway.

The reason I don't like a more aggressive initial flare is this: If it's overdone, then you might find yourself out of airspeed and rotor rpm for the final flare. Of course what works for me might not for others and I'm not trying to insinuate your technique was wrong. I'm not an instructor. I'm just sharing what works for me.

I do feel though that power-off landings are a "one-chance-to-get-it-right" advanced maneuver that should be worked into very carefully... especially by low time-in-type pilots. Anytime you change aircraft, or the aircraft configuration, it's best to approach such maneuvers cautiously over several hours.

Hang in there!

John Landry
PRA Chapter 30
Shoreline, WA

[Harry_S.]

David:
I sense that you are a very strong individual. I also sense you will overcome this crucible. God bless.


Cheers :)

[C. Beaty]

I can recall two helicopter pilots flying my old round tube Bensen with no prior training. They had of course spectated for quite a while.

Neither had any problem managing the rotor or flying the machine but both flared too high and thumped in without bending anything.

But spring landing gear can cause a problem depending on geometry and damping.

If wheel travel isn’t vertical, it can cause some pole-vaulting.

I saw a Dominator destroyed in similar circumstance when the pilot thumped in and got it dancing from one wheel to the other.

[Harry_S.]

Chuck B.: That cleared a thought in my mind. :o
I have thumped mine a couple times...it bounced from one wheel to the other wheel and then settled.


Cheers :)

[dwcreech]

Vance, yes I do plan on continuing my training.

I will admit here, and I'm not trying to be melodramatic or anything, that I got on the plane to leave Seattle with more than just a heavy heart. With over 2,000 hours of accident-free flying under my belt I'd just balled up a perfectly good aircraft belonging to a dear friend. On top of that I’m saying to myself, “You just took what is most probably the safest aircraft on the planet to fly, and turned it into a pile of rubbish on the runway. You don’t deserve to be flying these things!”

While on the plane on my return trip to Clarksville, TN, I was absent-mindedly flipping through one of their magazines and ran across this phrase… “Courage does not always roar. Sometimes, it is the quiet voice at the end of the day saying, ‘I will try again tomorrow’.” It was as if that saying was meant just for me and I said to myself, “You know what… I will try again tomorrow!”

I also remembered that I’d felt about the same way back in 1985 when I was involved in a car crash. I didn’t want to go near a car for several days but that didn’t keep me from driving again and, truth be told, I am probably a better, safer driver today because of it.

I cannot say enough good things about Randy Copeland, AAI, and others that are using their own time, money, and business expertise in an attempt to revolutionize the gyroplane industry. For an industry evolving around experimental aircraft, I was totally impressed by the level and quality of maintenance, the attention-to-detail in the training syllabus, and experience of the flight instructors. Believe me when I say that I’ve been to some Part 141 flight schools that did not come even close to this level of professionalism!

I understand that there is a mind-set, a paradigm if you will, about gyroplanes. I’ve been there myself, as many of you probably have at one point or another. When I first heard “gyroplane,” I was thinking about a lawn chair strapped to a powerboat fan, and dangling under a rotor system. I thought about the scenes from Mad Max and the “Gyro Captain.” If you fly one of these I’m not trying to bash you in any way but I think we are on the verge of breaking through this paradigm – something that is often referred to as a “paradigm shift” – and opening the eyes of a lot of people about this wonderful new (although really not new) experience, and I see all of you on this forum as pioneers in making that happen.

John, thanks for the advice… definitely good points to consider.

Jim, looking forward to a checkride with you would be like looking forward to brain surgery! ;) But, if one must have brain surgery, it might as well be from the best brain surgeon out there. I don’t mean this in a negative way at all, I’ve just heard that you are very thorough and that my ducks better be “dress-right-dress” – which is where they need to be.

[KenSandyEggo]

David, thanks for sharing all that info. About ATPs, I didn't mean to cast any aspersions toward you, but as I recall, when a monthly RAF crash was the accepted standard, before anyone was using a horizontal stab, a lot of the accidents seemed to include an ATP-rated pilot.

[ventana7]

David,

First off we're all glad your in one piece. Secondly we're all sorry you had an accident, damaged Ruby (which I also got much of my training in) and put a blemish on your flying record. Mostly I want to congratulate your courage to put up with the public scruitny of your worst moment in aviation. Your detailed post and willingness to discuss the incident will certainly help others of us make the same mistake.

Thanks.

Rob

[PW_Plack]

David,

Thanks so much for your post. Too often, we all seek to avoid embarassment by withholding accounts such as this which could help others be safe. Your contribution is appreciated.

I don't think the ATP paradox is caused by ego. I still think ATPs with tens-of-thousands of hours have been conditioned to assume their equipment won't bite.

Long-time fixed-wing pilots conditioned to smaller planes are accustomed to quick responses to pitch and roll inputs, which may make them candidates for PIO when adapting to laggy gyroplane controls.

[KenSandyEggo]

Rob posted, "Your detailed post and willingness to discuss the incident will certainly help others of us make the same mistake."

Rob, it's already been done. You don't have to do it too! :eek:

[birdy]

Thanx David.Not only have you got the balls to post that to a world audience,but you still remember nearly everything that happened.That takes nerve and understanding. ;)
All I can suggest to all newbys is ,read David's post a few times and try to understand how it'd feel when you get into a situation of brain overload.
Give yourself time,too much too soon will confuse if things go astray.

Thanx again David,and now get back on and give it hell mate. :D

[Jazzenjohn]

I just want to add my thanks for your detailed and descriptive account of the accident. The Ideal is to learn from others mistakes, though in reality it's not such an easy task. It's impossible if no one is willing to discuss what happened.
If you had read a similar account of an accident before you went on that flight do you think it would have kept you from making a similar mistake? Once the bouncing started from one wheel to the other what could have averted the outcome?
Thank You, John Anderson

[Chopper Reid]

Daves post proves the fact that it doesnt matter what you have flown previously or how many thousands of hours you may have etc, a gyro is a totally diferent kettle of fish to fly. I'm still finding it dificult to believe that a instructor would let you do more than one solo circuit before congratulating you, having a cuppa and then going out and do some more. Also, I'm amazed that you didnt have to do some up and down the strip balancing on the main wheels, getting used to the controlls /power/rudder etc .
Anyway, Dave, I'm pleased you are okay and I'm sorry about the prang, most of us have had a mishap of some sort at one time or other and if anyone hasnt had a ding yet then its only a matter of time !!
I wont retract my comment about ATP's or high time FW pilots not making good gyro pilots cause its true, it takes a lot of hours in a gyro to break the FW /helicopter mentality. Its not a crime, just a fact of life.

[teiland]

The roll-over in Randy’s plane is very unfortunate, but I think it is useful to be reminded just how easily this can happen to any of us. As I have circulated in the gyro community I have been astounded to learn how frequently roll-overs occur. My experience is in RAF’s and Sparrowhawks, but I know of many such incidents in other machines as well. Until a pilot gets really experienced, I believe this type of accident is only a small mistake away.

I spent 4 days this week with a 2000 hr. helicopter pilot, who had been here a month ago. He had similar problems flaring. I had difficulty getting him to land with the stick in his chest. He finally got it though and then did extremely well. It took him a while to “re-calibrate”.

While I am a fan of the medical issue benefits of Sport Pilot, I fear that the low hours required for this new rating has the potential to lead to an increase in roll-over incidents. The burden on the instructor is even greater here, in my opinion. It just doesn’t take much of an error or wind gust to make us vulnerable to a roll-over.

[Dean_Dolph]

The roll-over in Randy’s plane is very unfortunate, but I think it is useful to be reminded just how easily this can happen to any of us. As I have circulated in the gyro community I have been astounded to learn how frequently roll-overs occur. My experience is in RAF’s and Sparrowhawks, but I know of many such incidents in other machines as well. Until a pilot gets really experienced, I believe this type of accident is only a small mistake away........

While I am a fan of the medical issue benefits of Sport Pilot, I fear that the low hours required for this new rating has the potential to lead to an increase in roll-over incidents. The burden on the instructor is even greater here, in my opinion. It just doesn’t take much of an error or wind gust to make us vulnerable to a roll-over.Terry, I made a post in the Training forum that I hope you and every instructor that visits here will respond too.

Bless you all for getting that certificate!

[GyroRon]

I will understand if this question goes un answered, but I just gotta ask.... Who is going to pay to fix Ruby? The Student.... The Owner.... The insurance company.....????

[ventana7]

Ken,

I made a mistake in my typing- because I meant to type "NOT" make the same mistake"-- - is it clear as mud now?

Rob

[KenSandyEggo]

Rob, I know what you meant, but I just got this irresistable urge to tug your chain a little. :D

[Lotchik]

I was told about this forum only a couple of days ago and have already enjoyed reading many of the posts.
This accident really strikes home since I am a 1700 hour Army helicopter pilot, former instructor at Fort Rucker in Cobra's and currently building my first Aircraft - an RAF 2000. I am definitely going to remember this as I get started in my Gyro transition for real. I was once told that the most dangerous pilots are those reaching the next 500 hours - 500, 1000, 1500, 2000 etc. We (pilots) tend to feel invincible as our safety record improves. And while I am still without accident I have plenty of "nearly accidents" to say that very humbly. And yes most of those nearly accidents did happen fairly near a multiple of 500.
Through this forum and Dave's unselfish admission as to how he got into this, we are all benefactors to something I call a good accident. It is good because he walked away and we are all going to benefit from this reminder of just how quickly everything can go wrong. Thanks Dave and all the rest for your wisdom and sincerity.

Thanks for starting this great forum. I can only imagine how difficult this kind of info was to share even ten years ago.

[Chuck Roberg]

I sort of had the reverse flair height problem. I started in gyro's first then last year I got my Helicopter add on.

My instructor kept reminding me on my auto's to flair higher. He was concerned I would drag the tail boom on the ground.

I was used to flairing a lot lower in my gyro. I perfer an auto in a gyro a lot more than an auto in a R-22. :D

[Steve McGowan]

Don't worry bout the small stuff Dave, now your thru it and will be ok from now on. WE ALL learn from Mistakes. Machines can and will be rebuilt. Your the Most Important part of the pieces that make a gyro fly.

I was 7' tall when I began (SELF TEACHING) to fly gyros, now I'm 5' 12". So DON'T feel bad, You'd have 4 more to roll up before your even with me.

As " Bill Parson's " would say... " Ya Done Good Boy " now lets get back on and fix it..

me&BOOters

[Vance]

Some of you on this forum may not have had the helicopter autorotation experance, so I well share mine to round out the picture. Robinson 44. Without warning the instructor cuts the engine as we are on down wind, 1000 feet agl, eithty knots. I drop the collective and began to manage the rotor speed, too much and I pull a little collective, too little and I drop the colective. I pull carb heat, so the power recovery works. I manage airspeed at 70 knots and search for a place to land, aim for the place and continue to manage rotor speed and airspeed. Call the emergancy procedure. Continue to manage rotor speed air speed and aim for the spot. I am blind in one eye, so my depth perception is limited. At forty feet I hall back on the cyclic and it feels like the tail is going to dig a trench. Shortly there after I level the ship and if we are practicing to the ground the whole ship feels like it wants to roll foward. I find that this experance gets my full attention. If I flair too low I will dig a trench, it I overspeed the rotor and I don't die, I have wrecked some very expensive parts. If I allow the rotor speed to decay, it is a non recoverable event. If I allow my foward airspeed to decay, the flair won't work very well. Leveling the ship is an important part of the flair in a Helicopter.

Back to Autogiros, if I flair at forty feet and lose my foward speed I don't have much time to drop the nose, give it some power and try to slow my decent. I had a lot of trouble learning the speed of the flair and to keep pulling back instead of leveling the ship by centering the cyclic. I still have trouble with the height of the flair. I can land a helicopter by feel, this doesn't work so well in Autogiros. Jim Logan overestemated my skill level as he watched me fly his ship into the runway so I could get get a "feel" for the cabin height. This is only my experance, if I am doing something wrong, someone please correct me, because I love rotors and flying and I will continue to fly both. Thank you, Vance

[r.coplen]

Gyro Ron,

You asked the question, "who is going to pay to fix Ruby" I get to answer that question sense I own Ruby. The real answer is I do. I have not insured Ruby for hull insurance and if it were available I probably still would not have insuranced it for hull damage. The reason is that liability insurance is so important for a flight school that the cost of repairing a damaged machine is better covered by me than turning to the insurance company and risking cancillation. Hull insurance is available for individual owners of the major centerline thrust gyros through AIG insurance.

The take home, for me, from this event is: I will make sure students fly much longer with the instrutor before they solo. High time helicopter and fixed wing pilots both have automatic reactions that have to be overcome for gyroplane operations with longer dual flight time. If they solo, I will try to make it in their machine if possible. (And hopefully a SparrowHawk) If they solo in one of my aircraft, I will have a sign off that they will be responsible for some of the damage that could occur to the aircraft and if and possible all of the damage. Our flight school is in operation with Mariah (my black SparrowHawk)

Ruby is a good bird and you will see her in the air again. At present I am building another SparrowHawk that will be used by Moose Moore, my partner in Tennessee. David Creech will end up being the CFI for Moose and I know he will be a great a CFI. Our SparrowHawk for Tennessee is called the Hornet and she's a fine looking yellow and black SparrowHawk.

The event that happened to David Creech is a rear event. I have never seen it happen in the eight years I have been envolved in gyroplanes. I suspect I will never see it again. I think it is an issue that needs to be talked about but that is not a big issue in the overall view of gyroplane use. It will cost me some bucks but in the long run I don't expect to ever see this issue again. Our school will prevent it by dual training longer, using more balast, and making beginning solo flights very simple. Three normal landings and you stop and have a post flight review.

Attached is a picture of the "Hornet" in progress. David Creech will be the CFI flying this SparrowHawk and I know he will be a great asset to the gyroplane community.

[birdy]

Vance,
A common mistake people make if they're having trouble 'greasing it on' is their visual referance for altitude when close to touching down.
In a copter,you focus on the SPOT your intending to land on,coz you'v no choice but land with no ground roll.
In a gyro,you should start with some ground roll at landing till you get the 'feel'.And don't look at the point of intended contact, but at the horison.This'll give you a better hight perception.
If this is obvious just tell me to shutup.

[Chopper Reid]

Thats very good advice Birdy, basic but essential !!
R Coplen, instead of soloing your students in a beautifull expensive gyro, why dont you build or buy a second hand stock gyro thats reliable and easy to fly, that way if someone stuffs up then you havent lost such a big outlay and the amount of downtime is nil.
For what its worth Randy, I reckon one trip around the patch on the first solo is enough, bring them in for a cuppa and a chat then give them some more dual before sending them solo again. Thats just my opinion and exactly what my FW instructor did for me and I reckon its a good instructing. It gave me a chance to come down of my high of the solo and get more reinforcement of the basics and time in the aircraft. Adding ballast is a very good idea as well plus watch those high time FW and helo pilots.
I might add, I'm not an instructor.

[Dean_Dolph]

.....R Coplen, instead of soloing your students in a beautifull expensive gyro, why dont you build or buy a second hand stock gyro thats reliable and easy to fly, that way if someone stuffs up then you havent lost such a big outlay and the amount of downtime is nil.
.............Interesting suggestion! However, I think there is value in a new pilot being transitioned into a machine that is similar to what he owns and will be flying. So if a pilot owns a SparrowHawk then it makes sense to me that the solo needs to be done in a SparrowHawk. And if a person owns one then why not solo in the pilot's machine?

On the other hand if the AAI flight centers will be training pilots to fly other makes of gyros then it seems prudent to own other gyro examples. That doesn't reduce the opportunity to roll one over!

I also believe that a student should be discouraged from taking a full training course until the student acquires a gyro to fly. I can't help but feel that a large time lag between training and flying a personal machine has a built in potential for disaster.

PRA Chapter 62 had a grandoise plan to build a tandem two place trainer for local club training with the thought in mind that eventually a single place would be available for rent so people could build hours, gain experience, polish techniques and maintain currency while building.

Either machine could have been used for solo, depending on the type of personal machine they would be transitioning too. Alas, the plan has been slow to unfold with the trainer still being worked on.

[GyroRon]

Well Randy thanks for the Reply. I have just wondered who would be held accountable when something like this happens. In fixed wing training the plane usually has some insurance but normally not hull or not enough hull to fix it.... therefore Renters insurance is very popular with students and non owners.

I will have to admitt, I have made negative comments pertaining to instruction and gyroplanes, but the one thing I have never complained about - to the best of my memory - is that most CFI's don't solo you in their gyros. The least this rollover accident could cost is a set of blades, a new rotorhead bearing and a new prop. That alone is at least 3500$ but more likely it is double or triple that. Not to mention the downtime on the machine, which costs the CFI more money and costs the other students in time.

If I ever get my CFI rating you can plan on bringing your own gyro to do your solo in!

Again Randy thanks for the reply and I am very sorry this happened. But please don't be foolish and assume it won't happen again, If it can it will. What does Steve McGowan say?...... Murphey is out to get ya!

[Vance]

Thank you David, I guess I am doing the helicopter wrong. I always look as far out as I can so I don't get focused on the little picture. I don't do well if I focus near. I do the same thing in an Autogiro, I line up on the spot and then look as far as I can down the runway.

Next time I am in a hellicopter I will try looking closer. I am always a little confused visualy because of my monocularity.

In a gyroplane I like to come in with power so I can use the ground effect to calibrate my picture. When I come in with the engine off I pass thru ground effect a little fast to calibrate the picture. Thank you, Vance

[Udi]

...The event that happened to David Creech is a rear event. I have never seen it happen in the eight years I have been envolved in gyroplanes. I suspect I will never see it again...
Randy - I would second Ron's opinion that you should plan on it happening again. This is not a rare event - rollovers happen relatively often in gyros. In fact, this is the second such accident in a SH. This (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20031029X01824&key=1) was the first. Pretty similar circumstances, when you think about it. I am really surprised that you are willing to take this kind of risk on yourself. I wouldn't let students fly my gyro solo if it was uninsured.

I am not at all critisizing the SH as a trainer - I am just saying that thinking this kind of accident is a fluke is naive.

Udi

[The Rock]

Udi,

Randy didn't say it was a "rare" event he said it was a "rear" event. You know like a pain in the ass. :) :)

[Udi]

Yeah Cliff, I have noticed the interesting spelling... He also said this kind of accident never happened in the past 8 years and it will probably never happen again... It reminds me of a boss I used to have but that's another story.

Udi

[r.coplen]

Udi and Rock,

The event we experienced was the hopping on mains from one side to the other that was a leading cause of the rollover. I haven't seen that before.
I have seen rollovers at flyins but none of this type.

I guess my secrets out, I am strongly dyslxic and can't spell well. At least you knew what I was trying to say.

My goal is to train so that there is never a rollover. We have to get to that level. Fixed wing flight schools don't except flipping an aircraft as something that just happens.

[Cobra Doc]

Dave;
Great post. Let me know when you are ready to instruct. I think it would be interesting to "crew" for you again, this time in something in something a hair smaller than a Black Hawk. :D

[automan1223]

I feel for everyone involved here.

In my early training back with Bill Ortmayer I had a similiar problem that started at about the 7 hour mark, just when I thought I should be able to fly the darn thing. I would come in for a touchdown and bark and dribble the tires on the runway. If it was a higher machine there is a good chance I could have tipped it over. Then later in my training with maxie wildes I did the same damn thing out of no where. Dont ask me how, dont ask me why... in fact it was the most disturbing thing in all of my training. To screw up an important thing like a landing and NOT KNOW WHY !!! ... SO I stuck with it and then I learned how to dribble the machine from nose wheel to tail wheel. I had fully mastered the GYRO DRIBBLE 101. I could hop the airframe like a pogo stick. Most embrassing when eyes are on you too!!!

Now thankfully I out grew it and have made my approaches with less and less power. But it took time. It just did not come to me overnight. Dramatic changes in the flight envelope when you change weight so you have to be ready for the ship as it will throw you a curve ball when you least expect it.

Jonathan

[dwcreech]

Cobra Doc,

I was a "Snake Doctor" in a former life (67Y), and then decided it'd be more fun to fly helicopters than to repair them. I was right!

I don't recognize the name "Cody McCormick," though. Have we flown together before?

[asmuzsr]

Well this has not been a good birthday for me First I find out a good friend was killed in a plane crash after takingoff from our airport, now I find out my baby has been damaged. I know Randy owns her now but I had her first.
Glad your ok though and sounds like she can be fixed. Unfortunately for my friend, well we all weight the risks and go from there.
Thanks for the birthday wishs MJ.

[birdy]

The only time I'd let anyone fly either of my machines is after they'v handed over a cheque,equal to the replacement cost of the machine.
Bring the machine back without any more scratchs and they get their cheque back.


Even the experts are human,and I can't opperate without my babies.

[Aussie_Paul]

.... I transitioned Mark, my current gyro student, from my Hybrid into my 503 powered open frame single seat gyro. Mark conducted some balancing on the mains, then some strip runs at approx 5' and 10', finally finishing with 2 trips around the pattern. This was conducted throughout the day in 5 sessions.

Mark rang re training and asked if he could solo without bringing his machine?
Mark has a half share in a an almost identical machine. He lives more than 1300 miles from me and did not want to drag his gyro down, he would rather fly airline.
I told him that I could supply a similar gyro for him to conduct the required solo hours in. Today was the culmination of that phone call a few months ago.

A great day with another solo student to add to my collection. I just love this job!!!!! :D

O.B. Aussie Paul. :)

[Chopper Reid]

[QUOTE=Dean_Dolph]Interesting suggestion! However, I think there is value in a new pilot being transitioned into a machine that is similar to what he owns and will be flying. So if a pilot owns a SparrowHawk then it makes sense to me that the solo needs to be done in a SparrowHawk. And if a person owns one then why not solo in the pilot's machine?

No problems there Randy, if the student has a RAF then let him solo in his.

On the other hand if the AAI flight centers will be training pilots to fly other makes of gyros then it seems prudent to own other gyro examples. That doesn't reduce the opportunity to roll one over!

Thats true but it does make the cost of rebuilding it so much cheaper .

I also believe that a student should be discouraged from taking a full training course until the student acquires a gyro to fly. I can't help but feel that a large time lag between training and flying a personal machine has a built in potential for disaster.

I,m in total agreement with you there Randy!!

[Chopper Reid]

Great stuff Paul, The way you transitioned Mark is the way I reckon it should be done !! Well done !
Sorry about the big letters there guys .I'm not shouting, just the edit didnt work so well.

[Texas Armadillo]

PRA Chapter 62 had a grandoise plan to build a tandem two place trainer for local club training with the thought in mind that eventually a single place would be available for rent so people could build hours, gain experience, polish techniques and maintain currency while building.

Had a Grandiose plan? Hey, we're still working on it! Just for that, you don't get a lollipop at the next meeting!

We just spent 2 grand on a re-drive, and Greg put the new wheels on it last week. We be makin' progress.

[Cobra Doc]

Dave, I'm not sure anyone ever knew my last name. As a "cobra doc" I was always SP4 Mac, B-5 TC, 101st. After that I was SGT/SSG Mac or Mike Kilo, ATC at Bragg, Korea, Rucker. I know I've run into you somewhere, I just don't remember where.

[thallett]

Jonathan, this is just a comment on power-off landings when I was "training back with Bill Ortmayer": we ALWAYS did power-off landings. I never tried a power-on / run-on landing until much later. In Bill's machine, I recall several reverse roll-outs! Dave, glad you're oK with it: been-there done-that too.

[Lotchik]

Cody, Don't remember your name specifically but I flew Cobra's at Bragg Korea and Rucker. I was in Cobra Hall as an IP for 3 years. In those days I was a LT/CPT

Ken Cerney

[Doug Riley]

I teach the same way Tinkerin' Tom learned. All student finals and landings are at idle power (except for the ones that are ignition-off). It worries me to see so many pilots -- including FW ultralighters -- dragging machines in with power. If your airport's procedures require this, then perhaps you apply your aviation decision-making and accept the risk. Still, your "default" final approach should be at idle, IMHO.

This technique will provide you with a reasonable simulation of a deadstick with every landing you do. It also will allow you to get back to the field should your engine die for real.

Landing gears with simple swing axles that slope uphill toward a central hinge are subject to the kind of sideways hiphop that happened here. The harder you hit on one wheel, the more likely it is that the resonance will start.

I had the pleasure of demonstrating this charming phenomenon last summer with a lady student in the tandem Dominator. It was a somewhat windy day, and we dropped into a sinkhole right as we came over the threshold.
We dropped almost straight down, landing rather firmly on one main. I had taken back the controls by then, and we hip-hopped back and forth several times before things settled down. It's hard to know in retrospect if my control inputs made the situation better or worse.

Swing axles that are more or less parallel to the ground don't do this so readily. You have to add extra structure to a "high rider" gyro, however, to provide low attachment points for both the axle and the diagonal drag link that usually braces it. Arguably, a training aircraft should be designed to resist this kind of predictable problem, even if there IS a weight penalty.

[Udi]

Doug,

I think that the tendency of some gyro models to "hop" from one wheel to the other is more involved than just the axle swivel point. Common fixed wing airplanes like the C-152 and C-172 have their landing gear bending outwards, and you don't ever see them doing this hop from wheel to wheel. This problem has two more reasons that you have not mentioned:

One reason some gyros do this is because their suspension system does not provide adequate damping. When the gyro lands on a single wheel the suspension is absorbing, and storing, the vertical energy of the gyro. If it were to dissipate this energy - that side of the gyro would not hop back into the air - it would stay on the ground. Due to lack of damping, these suspension systems release the energy back to the gyro, hopping it back into to the air.

The second reason, which may not have been mentioned in this context here before, is the lateral proximity of the gyro's CG to the landing gear. A tricycle plane is more stable on the ground than a tail dragger because the CG of the tricycle plane is well ahead of the main gear. A gyro in the tilted-back landing position has its CG almost exactly above the landing gear. If you touch down crabbed - with the lower wheel ahead of the CG, you have negative yaw stability. That is why tail dragger airplanes are much more prone to ground looping than a tricycle gear planes. That is also the reason Ruby’s yaw excursions intensified from one hop to the next in Dave's accident.

Due to the nature of gyros and the need to balance on the mains during takeoff (which is not absolutely required by the way), we are kind of stuck with the CG close to the mains. But we have much room to improve the suspension, and provide better damping. This can be done with a simple auto-type shock absorber, or with a fancy g-force type suspension.

Udi

[Cobra Doc]

Ken C and Dave: More than likely I ran in to you guys at Rucker when I was the GCA Chief at TOI. We also had a lot of aviation support at FOC North And FCC Evenreach. Looks like there are a few of "snake charmers" hanging around this board. Since we are talking AH-1s and not AH-64s, there isn't much chance we could have NOT met in the Army!

[Doug Riley]

Udi : I agree in part and differ in part. The Cessna flat-spring gears have no built-in dampers at all, but the outward splaying/scrubbing of the tires IS an effective (sacrificial) damper -- as long as there's an appropriate amount of friction between the ground surface and the tire. The Cessna system doesn't work on ice, for example. I'm told that a Cessna will hop forever if you plunk it down firmly on ice, thanks to the absence of damping.

I would think that the Cessna gears would produce less sideways thrust when they flexed than does the rigid swing axle. The Cessna gear leg is all spring, and it's tapered, so it bends in a curve along its entire length. This should tend to shorten the distance between the wheel and the central attach point and somewhat counteract the outward motion. The typical gyro gear leg, OTOH, is rigid -- more like an early VW rear end, as Chuck Beaty has colorfully pointed out.

Whether the gyro has damping or not, the swing axle produces a sideways force as a necessary by-product of the rotary nature of its motion. It's going to cause a sideways acceleration even if perfectly damped. The only way to eliminate the sideways acceleration would be to eliminate the circular motion - - either make the gear perfectly rigid or use a more complex gear assembly that allows pure up-and-down motion with outboard springs/shocks. This would be heavy and draggy, though.

That said, the better the damping, the less likely that the inevitable sideways tossing action will become resonant and build up into a tipover.

[Udi]

Doug,

I wanted to see how much sideways movement there actually is due to the suspension in a SH/Dom-type gear, so I made some calculations. Unfortunately, I don't have a SH or a Dom at my disposal so I had to come up with some dimensional estimates. I used a construction photo that appears on the AAI website and I eyeballed the gears. This is what I came up with:

Bottom struts plane is about 3 ft long and at about 30 degrees from level.
Telescopic (upper) strut is about 4 ft long and at 60 degrees from level.
Maximum compression is about 3".

Doing some fancy trig I found that, at full compression (3”), the wheel would move up 2.55" and out 1.3".

So the outward movement of the wheel is in the neighborhood of 1.3". Assuming some surface slipping and tire deformation (throughing half a ton of aluminum and flesh around doesn't come so easily) -- I would think that the gyro is probably not moving sideways more than 1 inch.

We may be splitting hairs here, but I can't see how shifting the gyro 1 inch sideways can lead to this hopping from wheel to wheel. And how do you explain the oscillatory diversion? This is obviously an indication of an unstable system. What is the source of instability (other than maybe inadequate pilot inputs)?

A system that is oscillatory divergent must have 1. negative stability and 2. lack of damping. You can break the cycle by adding stability (moving the gear back) and damping.

Udi

[Doug Riley]

Udi: Well, dynamic/oscillatory instability comes from positive STATIC stability and -- as you say -- too little damping. Also needed, however, is a flow of energy into the system.

I doubt that the swing gear is dynamically unstable in itself, even with zero damping. I don't see how it could be. To build up divergent oscillations, a body needs transfusions of additional energy. A power-off landing is USUALLY a one-way street from the energy point of view. The body of the aircraft has X kinetic energy and can do nothing but either bleed it off or fail to bleed it off. It can't build UP kinetic energy without a source of such energy, which a gliding aircraft doesn't have.

Usually. A rotorcraft does have a reserve pool of energy in the rotor. I suspect that a pilot's manipulating the stick in phase with the hopping of the gear is involved when this hopping leads to larger and larger oscillations and a capsize. The pilot is unwittingly adding energy to the system from the rotor. An application of throttle could also feed in new energy that might find its way into the oscillations.

So the aircraft landing on one wheel isn't itself dynamically unstable, but the aircraft-pilot system is. This in turn suggests that, with this gear geometry, we need a "pilot damper" as much as a landing gear damper! (Of course, turning the pilot into a good damper is what training pilots to fly unstable aircraft is all about.)

The 1" side-toss seems to be enough to trigger this pilot-machine system, based on various people's experiences. Ernie warns customers about its possibility in Dominators -- or at least he did me. It really would be better -- since pilot damping is an advanced skill -- to avoid this particular design arrangement on a beginner machine. I'm not sure that a damping device can cure the swing-gear hip-hops.

[Udi]

I didn't completely consider the dynamics of this type of landing gear when I wrote my last reply. What I neglected to consider was the location of the sideways force vector. The gear is pushing sideways through the lower two struts. These struts are connected to the frame about 2-3 ft below the CG. The upper strut is more in line with the CG.

Since the sideways force is much lower than the CG, the gyro is not moving sideways at all - rather it is accelerating angularly around the roll axis.

If the gyro were landing on the right wheel, the sideways movement of the gear would roll (or accelerate) the gyro to the right. When it hops back into the air... well… I don’t know. I can't visualize that yet. It's pretty complicated.

Udi

[Udi]

...I doubt that the swing gear is dynamically unstable in itself, even with zero damping. I don't see how it could be. To build up divergent oscillations, a body needs transfusions of additional energy. A power-off landing is USUALLY a one-way street from the energy point of view. The body of the aircraft has X kinetic energy and can do nothing but either bleed it off or fail to bleed it off. It can't build UP kinetic energy without a source of such energy, which a gliding aircraft doesn't have...
The instability I was referring to is due to the CG being (maybe) behind the wheel in contact with the ground. I have seen a tail dragger plane doing a similar hopping dance after landing. The tail dragger is certainly yaw-unstable on the ground due to the fact that its CG is behind the wheels. I think the same thing happens to gyros that start hopping like that after landing and end up rolling over -- they had enough kinetic energy to feed this unstable ground maneuver.

Udi

[Doug Riley]

Good point about the line of action of the sideways thrust vector passing below the CM. The OTHER reaction force vector that passes up through the gear to the gyro creates a moment in the OTHER direction, though (it's a roughly straight up-and-down reaction that imposes a pure compression load on the vertical strut, its line of action being clearly located well to one side of the CM). This one tries to level the gyro. If the gear weren't restrained to a circular motion by the swing axle and instead could travel straight up-and-down, this reaction would be the only one applied to the gyro when the gear contacted the ground.

I'll have to chew on how all this sorts itself out (or fails to).

[gyropilot]

I teach the same way Tinkerin' Tom learned. All student finals and landings are at idle power (except for the ones that are ignition-off). It worries me to see so many pilots -- including FW ultralighters -- dragging machines in with power. If your airport's procedures require this, then perhaps you apply your aviation decision-making and accept the risk. Still, your "default" final approach should be at idle, IMHO.

This technique will provide you with a reasonable simulation of a deadstick with every landing you do. It also will allow you to get back to the field should your engine die for real.Doug,

I agree wholeheartedly with you about the benefits of being proficient in engine-idle (simulated dead-stick) landings. It sure paid off last summer when I had that very engine seizure in my gyro. All the practice engine-idle landings I'd made prior to that unexpected event paid off and it was just another (albeit quiet) landing... not even exciting. There's no better way to become proficient at them unless you practice, practice, practice... and every landing is a good place to do it!

However, there's another type of landing situation where I feel it's much better to keep partial power applied until the wheels touchdown... that would be when you must land with a stiff crosswind. The added rudder authority is essential for adequate yaw control, and the greater airspeed reduces the crosswind component to a manageable level.

It's all about managing risks... trading one for another. Good old Aviation Decision Making.

Fly safe,

John L.

[GyroRon]

John, good advise for those flying gyros with short tails. Tall tail people need not ride the power in even with Cross Wind, the tail will do fine with just the slipstream.

[birdy]

I can't understand why anyone needs to land cross wind in a gyro.??????
Even if I'm landing on a 10' wide road in a 40k CW, I'll land into it.
You wash of AS and rotor rpm while traveling CW down the road, but as you flare,you kick rudder and a little stick and bring the nose round into the wind, with 0 ground roll.

I don't fly a tall tail,for obvious reasons,and I'v never been caught without effective rudder responce.
When I do a power off 180* turn spot land ,starting from 40',I'v still got plenty of rudder responce,with or without wind assist, and my rudder ain't that big.

[ventana7]

Birdy,
Can you be a bit more specific. Do you fly down the runway (road) crabbed or cross controled then kick the rudder just before touchdown to land sideways to the runway and into the wind?

I'd appreciate any clarification.

Thanks,
Rob

[Chopper Reid]

Birdy, I got into trouble suggesting the boys over there, land into the wind as lots of them have to land at proper airports on the designated runway so they dont have the liberty like we do of landing however we like in the paddock !!!

[birdy]

Which ever your more comfortable with Rob. :) Crab'n is easer,and almost automatic,but if you fly into a 'hole' in the air when your crab'n 2' off the road,you could get into trouble when it touches the ground if you still have 'ground' speed. ;)

I never land crosswind,only land in wind that's blow'n cross the road, [more like landing cross ground :D ].IOW, touching down with the machine pointing into the wind and no roll. :rolleyes:

[birdy]

Why can't they just float down the RW till there're opposite the exit,then land and drive in???
No different to wot we do.

[ventana7]

Birdy,

I still can't picture it-
You are over the road going in the direction of the road with a 90 degree x wind- so you make a normal approach and at the last second you kick in the rudder- it seems unless your timing is PERFECT you'll stuff it up.

If you kick the rudder too early you are going to go off the narrow width of the road before you touch down- which means you are in the ditch or fence or whatever lines the road and if you kick too late and don't stop your rudder input before touch down you are going to touch down with lots of sideload and it will want to rollover-

sorry if I am being dense.

Rob

[birdy]

Hmmm.............maybe I should'a prefexed that comment with, "don't try this at home".

No offence Rob, I just didn't think it would'v been that hard.

[Udi]

If you want to turn into the wind just before touchdown, kicking the rudder is not enough. You have to change the direction of flight (momentum) of the gyro from parallel to the runway to into the wind. Kicking the rudder all by itself isn't going to change the direction of flight - it would only make you crab even more. You have to actually TURN into the wind.

I used to do that kind of landing alot with a hang glider. The idea is to turn into the wind until you can't feel any more crabbing. This is very similar to doing a crossed-controls x-wind landing, but instead of using the stick to keep the gyro over the centerline and the rudder to keep the nose aligned with ground tracking, you use the stick to stop any crabbing. If you feel that you are drifting to the right, turn left. If you are drifting to the left, turn right. It's really easy in a hang glider, but I have never tried it with a gyro. Rob is correct, you would need to time it right if you have a limited runway width to land on. But that is not really a problem when you have the whole Oz outback to land on... ;)

Udi

[birdy]

you kick rudder and a little stick and bring the nose round into the wind,

I did mention the stick origionaly Udi.

Rob is correct, you would need to time it right if you have a limited runway width to land on. But that is not really a problem when you have the whole Oz outback to land on...

I'm talk'n bout spot landing in a X wind Udi,o area needed.

[Udi]

That was a joke, Birdy... I know that you can spot land anywhere you want, but not everyone is Birdy!

Udi

[Chopper Reid]

That was a joke, Birdy... I know that you can spot land anywhere you want, but not everyone is Birdy!

Udi


Thats correct Udi, you do have to be very proficient in flying a gyro to do the landing Birdy is talking about plus fly a reasonably light machine. Heavier gyros obviously have more momentum and therefore take a little more stopping precisely and it depends on the speed of the wind, the stronger it is, the easier it is to have no ground roll and be precise in where you land it.
A good idea would to select a paddock to practise in till you get it right !!
You also have to be able to stop any drift of the gyro before touching down which might catch anyone trying to duplicate Birdy's CW/landing.
You are right Birdy, it isnt difficult to do but most people including myself like to be into the wind earlier so that the approach is under control at an earlier phase of the landing and wind speed /sheer/turbulence can all be calculated, even then it can be daunting to be flying into a 'one way area' and be looking at a shed or trees right in front of you with no escape route available. I found this to be a problem in my early days coming from a FW backgound.

[Chopper Reid]

Birdy, I owe you an apology, I didnt read the 40k cross wind part before, I take it all back, nearly anyone should be able to do that landing pretty well !!

[birdy]

I'll just shadap,it'll save alot of confusion. :rolleyes:

BTW Brian,I land the RAF on the 'G' spot, the same as the ferel :D .Just gota allow for the extra wieght. ;)