Bent the Golden Butterfly's Rotors

Doug Riley

Platinum Member
Joined
Jan 11, 2004
Messages
6,320
The reason I told students to do crow hops (AFTER they demonstrated that they could fly my trainer without my help) is that most were transitioning to open single-place gyros.

An open single-place gyro grosses at HALF the mass of a light gyro trainer. It also has a far lower mass moment of inertia. Both these things make it MUCH quicker in pitch than my tandem was -- even when the tandem was flown solo.

I intended the balancing exercise to get them used to the relative twitchiness of even a well-behaved 1-place, compared to the stretch limo they trained in.

It is not the ideal solution, for just the reasons we've seen here. Skittering about at almost-flying speed is a twitchy situation in its own way.

The correct thing to do when you pop off is to fly the aircraft (not necessarily LAND the aircraft instantly). Close the throttle gradually and settle in gradually, once you have the machine pointed in the direction it's travelling.

Don't do any of this in ANY cross-wind.
 

fiveboy

I FLY THE JUNGLE JET!
Joined
Jan 28, 2007
Messages
2,324
Location
Panama City Central America
Aircraft
AC Tandem Elite F30
Total Flight Time
Almost 200 hours
I was taught by a great CFI (Burgess). The training included having to balance on the mains for the length of the runway - demonstrated dualand solo and repeatedly. The reason (to my mind) that this is important is because in my take off procedure when the nose wheel gets light I increase power and hold the ship on the mains - off the tail wheel and off the nose wheel. This results in plenty of air speed and reserve and a flat take off (rather than popping up and being behind the curve).

I was NEVER EVER allowed to practice this solo with any crosswind whatsoever and never in winds more than 5mph at anything more than 3-5 degrees cross - max.

In reading what happened it seems to me that when he popped he had no reserve AS and that was that. The cross did the rest. Thats my take away on it.

Rotor blades are replaceable.

Fiveboy
 

Racer

Senior Member
Joined
Oct 9, 2006
Messages
1,594
Location
Colorado Springs, Colorado USA
Aircraft
Air Command CLT N7512X
I am so thankfully that I made it through the balancing on the mains part of my learning experience. I will admit that I came very close several times of bending up my rotor blades but somehow I saved it.
I know that I am not immune to damaging my blades even now but it does seem to reduce your risk somewhat with more seat time.
Learning is a stressfull time, and as this thread points out even after you feel you have a handle on things do not let your guard down because we can still get bit in a nano second. Thank you for sharing your mishap, it may very well save some others from having one of there own.
 

reelmule

Reelmule
Joined
Aug 19, 2005
Messages
388
Location
Cave Creek, AZ
Aircraft
Beech Baron C55; Piper PA 18 Super Cub; RAF 2000 gyroplane
Total Flight Time
5,000+ hrs;
Dan, from your self analysis, I can see that you will become one of the safeist gyro pilots on the planet!
 

Mark Sanders

Gold Supporter
Joined
Dec 29, 2006
Messages
606
Location
Phoenix, AZ
Aircraft
sparrow hawk
Total Flight Time
400
I scraped my rotor blades on the ground today doing high speed taxi runs. :Cry: I am not completely clear on exactly what I did/went wrong. Winds were variable but reported to be 230/05. The only runway was 14/32 which is means there was a 90 degree cross wind @ 5 knots. I was using 32 but the winds would occasionally shift and there would be a slight tail wind then change back to a slight head wind if not directly abeam. On the run just prior to the incident I considered changing directions while watching the sock showing a tail wind and then it changed back to a head wind so I proceeded on to 32. Things were going good and balancing on the mains well. I felt the wheels getting too light and thought I was going too fast and reduced throttle while adding just a little back stick to slow down a bit. That action caused the gyro to lift off about 3 foot. No problem I’ll just settle back down and was aligned well with the runway at that time. As it began to settle it picked up a hard left yaw that could not be corrected with full right peddle. I added full throttle to try and fly out of it. The controls were very mushy and the gyro seemed unresponsive. It still settles, it now picks up a right yaw from what I believe was the engine spooling up and the rudder taking effect. Now I touch down in a right yaw and the gyro rolls left. The blades scrape the runway 3 times before I get it level again. Now I run off the right side of the runway and stop in the grass. Fortunately it did not hit a runway light. Except for the blade tips being turned up about 4 inches on the end, their does not appear to be any other damage. I will inspect it more toughly tomorrow. Not a good showing for my debut at the airport with my gyro. All my friends will be vindicated; you know the statements where they say you are crazy to fly those things........... The wife is suggesting I get out............

Not a good day.

Man those blades were tracking good after balancing them. There was no stick shake at all. It was a sickening feeling on the stick as the rotor drags across the deck. I could feel the rough surface and scraping of the runway and every pebble it slid over in the joy stick. There was no hard yank or shock feed back through the controls, just a grinding vibration in the stick.
good save! you said I felt the wheels getting to light and thought I was going to fast and reduced throttle while adding just a little back stick to slow down a bit. reduceing the throttle was good the back presure is what did it. you left the ground and the crosswind started to point you in the wrong direction. that is so easy to do then your angle of attack was so great that you did'nt have enough HP to keep you in the air long enough to add forward presure and fly out of it. Just trying to go over it in my mind. eather way Ill say what steve told me when I was picking up the peices. You know what you did wrong and you will never do it again. thanks for sharing.
 
Last edited:

All_In

Gold Supporter
Joined
Apr 21, 2008
Messages
14,625
Location
San Diego, CA. USA
Aircraft
Piper Archer, Aviomania G1sb
Total Flight Time
Not sure over 10,000+ logged FW, 260+ ultralights, sailplane, hang-gliders
Oh thank you Mark that explanation let me understand what happen in FW pilot terms I can understand. I love this site!!!
 

fiveboy

I FLY THE JUNGLE JET!
Joined
Jan 28, 2007
Messages
2,324
Location
Panama City Central America
Aircraft
AC Tandem Elite F30
Total Flight Time
Almost 200 hours
John

To my understanding, what it means is he popped up by giving it too much back stick too fast. Rather than create drag only (to slow down) while he was scooting along the ground he created lift.... but he didnt then have enough forward AS or height to point the nose down, lower the rotor angle a bit give it throttle and get back enough AS to maintain lift to fly out of it. The Xwind then weather vaned him into a yaw.

Fiveboy
 

automan1223

Banned
Joined
Nov 3, 2003
Messages
3,760
Location
Oriental, North Carolina
Aircraft
2p Tandem Air Command "Big Red"
Total Flight Time
250
Speed is your friend !

Speed is your friend !

I know I am going to rub a few the wrong way here but my prolonged training allowed me to do the training in slow motion. That means I got to go and "do over " skills I thought I had down. This allowed me to spend a painful amount of time thinking the whole flight / training of flight thing through.

2 most dangerous things in a gyro are crow hops and balancing on the mains. The gyro is not meant to do this kind of non flying until it is up and flying. If you are a low time pilot and even a good high time pilot there is no reason to be flying behind the power curve close to the ground.

In many gyros pilots get a false sense of security with landing at slow speeds. Remember your "control" is only there when AIRFLOW is going over the rotor and THE TAIL and the PROP. Many times you can get in to a settling at a slow speed and your gyro can "come off" tail authority because of slow airspeed. The description of your yaw with no authority is classic gyro doom that has gotten many pilots. Almost got me once too and for NO GOOD REASON. I was trying to do a stop and drop landing which has no place in most flying situations

You are smart enough to recognize to understand what you did wrong. With no prop thrust, low or no airspeed, challenging atmospheric conditions you are playing with the devil and the only way to of saved it was to add throttle and fly the bird. Wallowing in ground effect is a quick way to learn a hard le$$on.

You cannot safely pull all your power and have no airspeed until your tail wheel is on the ground.

I have a big problem with the old time flying syllabus and sincerely believe it has led to many fatals, and accidents.

Crow Hops,
Stop and Drop landings

For more advanced pilots, not a beginner.

Jonathan
 
Last edited:

Resasi

Gold Supporter
Joined
Jul 2, 2007
Messages
7,355
Location
London/ Kilifi Kenya
Aircraft
Gyrs, RAF 2000/Mgni/Bnsn/Hrnet/Mrlin/Crckt/MT-03/Lyzlle AV18-A/Prdtor. Pax ArrowCopter
Total Flight Time
100+ gyro, 16,000+ other
Robert I think you made a most important point and good explanation "increase power and hold the ship on the mains - off the tail wheel and off the nose wheel. This results in plenty of air speed and reserve and a flat take off (rather than popping up and being behind the curve)." when the inadvertent/unexpected take off occurs.

It seemed that it was the inadvertent pop up with back stick and deeper into the behind the drag curve that increased vulnerability to the crosswind.

Perhaps to fly out of a pop up as Doug said is a better technique to be taught and practiced in a situation like this, runway available of course.

My take is still that wheel balancing and crow hops are valuable and necessary exercises that minimize the risk of fatality at possible the expense of bending the gyro. We have had three recent incidents that were expensive and embarrassing but not fatal. At altitude they would have been fatalities.
 
Last edited:

tadgyro

tadgyro
Joined
Aug 20, 2005
Messages
787
Location
Retired to El Mirage dry lake"
Aircraft
Bensen Type,KB2, KB3 and Gyrobee
Total Flight Time
25 + years
[QUOTE=bpearson;241899]In the UK we have had two types of self taught gyro pilots.

When the Air Commands were popular and instruction was short in supply compared to the number needing it, would be gyronaughts tried to fly and if they got off the ground........body bag.

Other hand, dozens followed the Benson method without problem. I suspect without an instructor to monitor progress self discipline is needed.[/QUOTE]


Right on
Tadgyro
 

tadgyro

tadgyro
Joined
Aug 20, 2005
Messages
787
Location
Retired to El Mirage dry lake"
Aircraft
Bensen Type,KB2, KB3 and Gyrobee
Total Flight Time
25 + years
My take is still that wheel balancing and crow hops are valuable and necessary exercises that minimize the risk of fatality at possible the expense of bending the gyro. We have had three recent incidents that were expensive and embarrassing but not fatal. At altitude they would have been fatalities.[/QUOTE]

Any one who follow DR. Bensen fly manual can get wrong. Most of the Gyro pilot (All timers) who follow his instruction come to be the best pilot in gyro and also CFI instructor like Marion Springer and only the one who has self discipline and patient come to be god flying and long living pilot like Ed Nelesky or Chuck Vanek
Tadgyro
 

ckurz7000

Senior Member
Joined
Nov 7, 2006
Messages
3,438
Location
Vienna
Aircraft
ArrowCopter
Interesting thread. I trained in Germany (dual place gyro with instructor in the back) and the balancing on the mains exercise was introduced at an advanced stage, only after I had soloed. I share the opinion of other posters that this exercise has a too high risk/benefit quotient. What we did do, however, was take off to a hight of about 5 feet and immediately land straight ahead. These were normal takeoffs and normal landings. Nothing behind the power curve. They were part of the engine-out exercises in that he would chop the throttle and I had to push the nose forward and land in a normal way.

Nowadays I will drive a little slalom down the runway while balancing on the mains and then lifting the right wheel and setting it back down, then lifting the left and setting it back down. This is an advanced exercise required for flight instructors and never taught to student pilots. Don't try this at home and don't do it in any kind of cross wind.

-- Chris.
 

dcarr4321

Dan Carr
Joined
Mar 21, 2004
Messages
133
Location
Friendswood, Texas
Aircraft
helo & fixedwing
Total Flight Time
1500
Good News on the Gyro Damage Assessment

Good News on the Gyro Damage Assessment

I completely dissembled the rotor head and control links for inspection. All the components checked good after being measured for deformation and die pen testing. No deformation or cracks on any components or on the mast. All the old rotor head bolts will be disposed of and replaced with new ones. The rotor bearings will also be replaced but I think they are ok but don’t have any way of testing it. The only damage other than the blades was a slight deformation of two AN4 mounting bolt holes on the flap retainer. Some of this was due to previous thread galling and not related to the blade strike incident. I will chase the threads of the existing holes and drill and tap two additional holes. On inspection, the flap retainer bolts were too short to begin with and new bolts with longer grips and drilled heads will replace the old ones. I like the safety wired bolts on this application better since there are no lock nuts to retain them. The front wheel fork was every so slightly bent less than 1 degree from vertical. It will be straightened out and reinforced with an internal stiffener to be better than OEM. The aluminum wheel rim will also be replaced.



Got lucky on this one.:whoo:
 

All_In

Gold Supporter
Joined
Apr 21, 2008
Messages
14,625
Location
San Diego, CA. USA
Aircraft
Piper Archer, Aviomania G1sb
Total Flight Time
Not sure over 10,000+ logged FW, 260+ ultralights, sailplane, hang-gliders
Thanks for the excellent tear-down report.
Sounds like she'll be repaired correctly and back in service in short order.
 

dcarr4321

Dan Carr
Joined
Mar 21, 2004
Messages
133
Location
Friendswood, Texas
Aircraft
helo & fixedwing
Total Flight Time
1500
Back in the Game

Back in the Game

Finally started working on the gyro again. After several delays at getting it going, the rotor head is back on the gyro. Waiting on parts delivery and hurricane Ike repairs to the home and work to repair damage delayed the gyro project. Now it is just the usual delays like missing a washer, bolt etc. “That washer was there with all the new fasteners now it seems to have disappeared.” DANG IT !!! Where do those things go? Next I need to string and balance the new blades. After the incident of damaging the blades, it has really been hard to get motivated to get back on track. At 53 years of age and until now, I have never had an accident or incident or anything either flying or driving. Damaging my blades was really discouraging. It made me question if this Gyrocopter goal was something I should be perusing. But I have gone this far, why quit now? My experience has been that anything worth while was never easy. I will let you know how the test flights go.:plane:
 

Mike Stone

Self Induced Grounding
Joined
Apr 11, 2006
Messages
456
Location
Cypress, Tx (near Houston)
Aircraft
none
Dan...

Keep the faith...I know I have to some times. My gyro has its airworthiness but still needed to be painted past the primer stage. I took last Saturday to go to the hanger and strip off the instrument pod, tail section, wheel pants, and cabin pod from the ship. Also hung the ship from the rafters to take off the shocks for painting. They are at the house now awaiting my attention. The ship now looks a far cry from what it did on Friday.


...Mike:whoo:
 
Top