I Crashed My Gyro Butterfly G095

[Greg Mitchell]

G'Day Gents,

Here is a link to the Aussie Forum, where I have detailed my accident.

http://www.asra.org.au/forum/topic.asp?TOPIC_ID=1095

Mitch.

[Heron]

Aw c'mon man you did not!!!!
Sorry to hear that.
Heron

[barnstorm2]

Crap. The important this is you are ok. It is just metal and you will have it back together soon I hope.

You should be able to get some flight time in at Mentone, so there is something to keep up your spirits as you start the rebuild!

[Friendly]

Glad your ok Greg! Can you cut and paste your post on this forum?

[scottessex]

Glad you are OK, crashing sucks! I hope you will rebuild and enjoy many happy years of flying. I'm glad I didn't quit after mine!

[ventana7]

Mitch,

What a bummer.
I read your post and it seems you have a full grip on how not to make the same mistake twice-- that's all we can ask-- that we learn from them.
See ya in Mentone.
Rob

[Greg Mitchell]

Sorry Mark,
I should have realised the link would not let you access our accident thread. Hey join our forum too. Obviously there are comments being posted on our accident thread that may be of interest to you. Lot of Aussies on here now. Well here it is.


Dumb, Dumber and DUMBER!!!!!

Saturday 18th June, 2005 at 1300 hrs, I drove through two fences at the Northern end of runway 32 at high speed with not enough rotor speed (blade flap)and forwarded somersaulted gyro. Requiring an extensive rebuild of the front end, rear keel and tail.

This accident was the result of my stupidity and has nothing to do with the design or effectiveness of the Butterfly gyroplane OR gyroplanes generally.

DUMB.
1. I deviated from a flying schedule I had set myself for the next four days, which covered the period of the Opps Mgr comming to Tassie Mon 20th - Tues 21st, to meet the local crew and effect BFR's. After recieving a phone call Saturday morning at 1030 hrs, I attend at the airfield on short notice.

DUMB.
2. I took my kids with me and whilst they were locked in the club house and being look after by others, with strict instructions that my kids not be let out till I returned..,..the stress levels exceeded levels normally experienced when kids are not present.

DUMB.
3. Last time I flew, Butterfly flew fine, though I thought there might have been a little more stick shake than was acceptable. Because I had an old benson hub bar with irregular worn holes fron the cotton reels on sides of hub block, I had previously shimmed these to get correct tolerances. I decided to rotate the head 180 degrees.
I also adjusted the trim string for some more nose up as hands free she gentle noses down and to the left.

DUMBER.
4. Whilst back tracking runway 32 I thought the blades had not come up to rrpms consistent with previous experience (as limited as that is 15 1/2 hrs solo). So when I turned around for take off on runway 32 slight N/W 10 to 15 knots, I placed her into the wind and spun up again. I held the disc at full back stick and used some thrust under brake to give additional airflow to help bring them up.
I began to taxi, by the top of the first rise the blades were not comming up as I would have expected or liked.
By the second rise in the runway again not quite cooking. This should have been my abort point. Another peek and the blades looked good to go.

STUPID.
5. During the last seconds of course I realised I was in trouble. I thought the nose had come up and ordinarily I would have been off and away. Whilst all this was going on I have strayed left of my track and clipped a tyre marker (not known till later observing the site). Later it was suggested this might have popped me into the air, however after going back and looking at the site, I found my wheel tracks and they continue on past the tyre.
Approximately 4-5 mtrs before the first fence the wheel tracks disappear.
I tried to horse the gyro over the fence. I felt the right to left knocking on the stick, indicative of flap as a result of not enough rrpm. The first fence flipped me sommersaulting forward. I thought I had then rolled left and then right comming to rest on the right side of gyro nose gear burried into the soft ground.
It seems that the first full tumble resulted in a roll left landing on left mains, which has then bounced me back onto the right side of gyro comming to a sudden halt. The gyro travelled approx 26 mtrs from the point where the wheel tracks finished to final resting point.

Classic case of series of poor judgements and decision processes.

The high rider configuration of the gyro (Note I did not say CLT Hey John.)I believe with its tall front strut and instrument tube and pod, saved me from getting cut.
The extremley strong front end keel configuration saved my legs and upper body from contacting the ground.

I apolagise to every member for my stupidity and very poor decision making processes effected on this day.

This accident in no way reflects on the general discussions about the safety of gyroplanes. THIS WAS PILOT ERROR.
Gyroplanes are the safest aircraft to fly and operate, given rational, sensibile approaches to the sport, which I was sadly lacking on the day.

Damage....Front end/rear keel/left push rod/tail/blades/prop/torque tube/jesus bolt/bearing/lower rear engine mount plate/head plates (maybe)instruments and instrument pod. I figure about $4000-$5000 will get me up again. Looks like I'm giving up smoking after 30 years.

There was no visible damage to the mast or engine mount tube to mast arrangement. I have been told that there may well be a twist in the mast but the left head plate may have prevented the twist as it is slightly deformed. Yet to be determined.

I am rebuilding and will always be involved with gyroplanes. Fortunately I will get to fly with some good blokes whilst in the US (PRA/OSHKOSH Conventions) and my Mate Nigel will take me up in his tandem trike periodically to satisfy my need for flight whilst I rebuild.

This was a scary event and I truely hope that you new blokes comming in will see this accident for what it is. Major case of Pilot error. This will not happen to you if you take your time and slowly bring your blades up and make sensible decisions to abort at pre-determined points. Never assume your blades will do what you think they should, let your blades tell you when they are ready. Dont get ahead of what your aircraft is telling you.

Fly Safe

Mitch.

[Greg Mitchell]

Cheers Gents,
It's good to be in a position to rebuild, albeit, slowly. Looking forward to 'unwinding' in the USA.
Mitch.

[Doug Riley]

Mitch, what type of blades do you have? Some are more ornery than others about getting into late-stage flapping.

[B8MFlorida]

Mitch-
Been there, done that, got the T-shirt!
Good Luck on your rebuild!
Thank God-those powerful forces that were plenty strong enough to bend those tubes like tooth picks, stayed away from your bones.
John
Pittsburgh

[Brian Jackson]

Sorry to hear that, Greg. But we're all very glad you're unhurt. The crumpling of the airframe instead of your bones is a testament to the ship's good design. I hope your rebuild goes well and you can get her back in the air again.

[Harry_S.]

Golly...what a sad turn of events, Greg. I believe it when you say, you'll be back.

If I were going to Mentone, you would be off the ground with me...for a couple hours or so. Wishing you the best. ;)

.

[PW_Plack]

If stick shake was increasing and the machine tried to pull left, could that have been a sign of a bearing binding in the head? Could the bearing eventually have been binding enough to make attaining flight RRPM difficult?

[Greg Mitchell]

G'Day Gents,

Doug, Blades were 30 year old original Benson Blades 21' 9" and hub bar.
Paul, the bearing did not bind in the head. Only felt the stick knocking right to left as it left the ground. I recollect maybe two or three knocks, by this time I was going through the first fence.
This was no fault of the gyro.
Pilot Error all the way down the line.

Hey Doug,
Off Topic.
I read an excellent thread once about the pros and cons of different tails, which I remember you were contributing to. There some discussion in Oz at the moment about flat spins and recovery methods. I seem to remember you detailing your thoughts on the free flying tail but I can't locate the info, could you point me in the right direction.

Thanks Fella's appreciate the fellowship.

Cheers,

Mitch.

[REDHORSE556CES]

Thanks to God, Shiva, Bhudda, Allah, Wakantanka or what ever deity any of us happen to believe in that you are o.k. From the looks of it, it could have been much worse.

From the pics it appears that since half of the propellor is missing it struck something during the mishap. Do you think it might have done anything to the crank or connecting rods when the prop struck whatever?

[stuart]

Glad you weren't hurt Greg; good luck with the rebuild.
Doug, Which blades are bad about late-stage flapping? thanks, stuart

[Doug Riley]

Stuart, Dragon Wings are notorious for flapping at fairly high RPM. A good prerotator and judicious throttle use solves the problem.

Bensen blades set on the original stock scribe marks are at 1.5 degrees pitch and aren't very flappish. Many of us used to increase the pitch to 2 deg. or more, which also increased the tendency to flap. Bensen may himself have increased the setting of the scribe marks at some point, too.

I had post-liftoff flapping on my Rotordyne-equipped Gyrobee once. I did what's normally advised -- added some forward stick pressure and waited for a recovery. It worked. Luckily I didn't have a fence right in front of me. Rotordynes are fairly forgiving, as a rule.

Mitch, I can't recall a specific thread about all-flying tails; it's come up several times. Their major advantage is that they are simple to build. They can't generate as much lift per square foot (for a rudder, lift is sideways) as a conventional fixed fin and moveable control surface. In theory, they require an anti-servo tab to have a fully normal control feel; without one, they either have no feel or have a moveable neutral point that lines up with the direction of the gyro's travel (even in a slip). The moveable-neutral problem can be reduced through the use of centering springs.

In practice, the all-flying rudder on my Air Command seemed to fly fine to me, despite the theory. I don't know how others may feel about it. The Butterfly rudder looks like it's the same as the A.C.

[stuart]

Thanks Doug, stuart

[Gyro-nut]

Looking on the bright side, 3 good things came from this accident:

1) You walked away

2) You've learned from you mistake and posted to this forum so that others may learn from it as well

3) You've found your motivation to quit smoking :)

[Greg Mitchell]

Hi Doug,
I didn't think the bensons were all that troublesome. I'd had a little flap once or twice early on, usually by starting my roll with two much throttle, immediate stick forward and shut the throttle worked fine.
Honestly don't know what the pitch was set at. Bought the blades for $500 AUD.

The tail is an AC with a stiffener tube up through it to carry the HS support struts. It faired very well considering and I have been given advice on glass repair. The question re: the free flying tail inquiry came out of recent discussions in OZ as to the recovery methods used to get out of flat spins. And I seemed to recall you mentioned something once about the effectiveness of variously configured tails given this situation.

I'm going to cut and paste some further comments I made on the OZ forum re the accident and would appreciate any feed back and advice, from members.

"""Revisiting the accident (as you do), I'd just like to clarify the possible significance of rotating the head 180 degree.

Having shimmed the worn side faces of the hub block (30 years of cotton reel wear and to different depths) and got the block centred, when I rotated the head the hub was likely no longer centred, contributing to out of track, reducing the likely hood of bring the blades up at expected rates and the onset of late stage flap due to the excessive forward ground speed.

Another thing I thought may be helpfull in the analysis, given previous threads, is that once arriving at the second rise (essentially the abort point), the ground then drops away about 7 degrees. Wind is comming at me off my left hand side. Once I head down hill still with full back stick, I now have more like 11 degrees instead of 18 degrees. This would have put me further behind the 8 ball again. I make the assumption that the wind is parrallel to the ground as the ground is dead flat in the paddock at the end of the down section of runway. And given the relative short distances involved."""

Cheers,

Mitch.

[Doug Riley]

I suppose that a badly out-of-track rotor would be harder to get spinning, since it you'd have a one-per-rev vibe all the time that might make the 2/rev flap harder to detect at first.

A downhill runway slope makes it harder to control your speed.

I'd initially suspect that the Bensen blades were pitched up more than the old factory spec. At stock pitch, they're the brand least likely to flap of all. They're not prone to late-stage flapping unless you REALLY horse them around. I wonder if some prior owner re-worked the hub or otherwise increased the pitch.

One anti-flap technique is to keep the prerotator enggaed during the first part of the takeoff run. This provides an extra RPM boost and governs the engine to make overspeeding less likely.

[Hognose]

Mitch,

Glad you're OK. I can't make Mentone this year; if I don't catch you in the UL/gyro area at Oshkosh, make sure you stop in and say hey at the Aero-News mobile office (one of those construction office trailers, in the parking lot at the media centre).

Same goes for all of you. If I'm not there tell Jim or Pete or whomever, that I owe ya a cold water or coke. (grin).

cheers

-=K=-

[Greg Mitchell]

Kevin,
Will do, looking forward to it. Just look for an ugly bloke with a 'gotee' wearing something with Aussie insignia.
Doug,
Thanks for the feedback. No pre-rotator on Butterfly, been spinning up to 50 -60 rrpm from the seat.

[StanFoster]

Greg: Sorry to hear about your mishap. I will be looking for you at Mentone.


Stan