ELA rotor strike

[dinoa]

Here is an e-mail received from ELA showing the effects of a rotor strike.


"The Gyroplane # xxx had a crash few days ago.

At the take off the rotor touched ground 4 times but the student pilot did not understand it, and continued the flight for 40 minutes without any problem. After landing they saw that the rotor had distortion (see attached photos).

Once again a full skilled pilot started to flight by that and had a test flight in all velocities and conditions carefully and found that there is not any change in performance and it had no vibration.

Please let us know what your opinion is in this respect. Also please let us know if we have to replace the rotor"




Dino
Athens, Greece

[dinoa]

some more pictures.


Dino

[Vance]

In my opinion the rotor blades should be replaced and the rotor head and mast should be carefully inspected for damage.

Thank you, Vance

[bpearson]

In my opinion the rotor blades should be replaced and the rotor head and mast should be carefully inspected for damage.



and the 'test pilot' sectioned for his own well being!

[brett s]

I can't imagine that someone would even have to ask - this is the sort of thing that makes other people in aviation think gyro pilots are crazy!

[Mike Schallmann]

After reading this thread is there any wonder why I often respond as I do? Let see --after the accident a FULLY SKILLED pilot flew the machine -- IMHO that "Pilot" was an IDIOT----

This incident would be the same as somebody groundlooping a FW =bending the wing tips and taking it up again--pure STUPIDITY on ALL parties involved

Diplomacy is NOT my Forte--see sig--

[Racer]

Wow!
Are those Sport Copter Blades?

[M._Springer]

that much more flight instruction is in order for the student pilot who flapped the blades. That is such a beginner thing.
As for the so called 'skilled pilot', he seems short of good judgement to say the least.
Marion

[dinoa]

Wow!
Are those Sport Copter Blades?

Racer,

They are ELA blades. Composite with aluminum spar.


Dino

[helipaddy]

He must be a Jodel pilot..

[Mike Schallmann]

Those blades are DEFINITELY trashed--an Airworthy repair is NOT possible--

[scandtours]

Dino,
There are NO full skilled pilots but only alive ones...
Mike Shallmann and M. Springer used the correct adj regarding this pilot.
It shoulden surprice me to hear from this skilled pilot that all pevious vibrations disappeared after inc.
Student's instructor, was he a CFI or a gyropilot who could just fly?
I doubt n both.
Ground the gyro Dino. For sure there are more hidden damages on the rotorhead, mast.
Giorgos

[gyro]

Blades and rotor heads are tougher than you think. Perhaps the pilot did take a chance on flying bent blades but I would imagine he or she took there time bringing them up to speed and hopfully flew in GE for a while before climb out. The fact that the pilot and gyro are in once piece proves the structural intergrity of both.

Anyway glad nothing serious happen and do replace the rotors. check for play in the head but I bet its ok..... check the mast where there are bolt holes.

[Gyro_Kai]

The composite of the blades may have suffered structural damage like torn filaments, which are at first invisible. Gradually the weakened structure will continue to tear, until it comes apart at a time you least need it.
The invisible aluminium spar may have developed hairline cracks which will widen over time.

I would not risk it,

Kai.

[dinoa]

Quote "Ground the gyro Dino. For sure there are more hidden damages on the rotorhead, mast."



Kalimera Giorgos,


The gyro is not mine to ground, nor was I the "skilled pilot".

I was forwarding a message sent by ELA to many on their mailing list as I thought it would be of interest to the Forum.


Dino

[scandtours]

Quote "Ground the gyro Dino. For sure there are more hidden damages on the rotorhead, mast."



Kalimera Giorgos,


The gyro is not mine to ground, nor was I the "skilled pilot".

I was forwarding a message sent by ELA to many on their mailing list as I thought it would be of interest to the Forum.


Dino

Gia sou Dino,
That I understood and I was not reffering to you. But hope you could persuate them to watch out. I know you are invovled in aviation for many years and they could listen/respect your advices.
Giorgos

[Resasi]

Good to hear and see the blade integrity allowed the student to get away with that blade strike.

He should have been instructed on actions to be taken upon any incident accident during take-off roll. Not just carry on regardless. Very lucky to get away so lightly.

He will have been given a very bad example to see some other person fly the same machine after that damage had been discovered.

As for the 'Oooh look the wing is bent but it flies OK will I have to mend it??' That any pilot would even consider trying it out after that damage seems incredible. Suppose a total lack of imagination mixed in with a healthy dose of ignorance and blind faith helps.

[Mike Schallmann]

gyro-minigun man --to reply like that shows total ignorance of adequate safety procedures. Flying a damaged aircraft may be accecptable in some EXTREME cases but in this case it was not. The pilots actions demonstrated a total lack of self control and concern for the safety of others.

The stuctural integrity of the blades was NOT proved nor were the actions of the pilot justified.

He survived by pure DUMB LUCK.

To think otherwise would indicate an attitude that the blades were safe to fly as no serious or significant damage had occurred --and that would be ABSOLUTEY ABSURD!!

[brett s]

I'm with Mike - a rotorblade structural failure in flight is generally fatal, being in ground effect won't make much difference if one departs or diverges much from the normal plane of rotation. Even on the ground it can kill you, just depends on how lucky you are.

[freebird]

Wow!

I wouldn't even fly on a nose wheel that only needs a little air every 10 days or so.
After seeing someone come back after a flight with that kind of damage, I could however see myself spinning it up and maybe even balancing on the mains just for the educational value, but NOT leave the ground.

I hope that if I ever experience a ground strike, I have such mild results.

[gyro]

Mike, I think you misunderstood what I was trying to say. I did not condone what he did nor his actions....all I was saying it that when some body has a blade strike (not a roll-over) at full rotor RPM is that the mast and rotor head should be ok but still inspect it. I did say he took a chance flying it and I don’t know what his situation was but if it was for test/evaluation as the guy seems to state then I hope he took the precautions down low to make sure it was not going to get ugly!

If you think for one minute that I have a disregard for safety and I’m a super glue and duct tape man (fly it anyway) then you misjudged me….

And the fact that the gyro did hold together does in my book show some form of structural integrity….is it safe to keep flying for hours on end? NO and unless this happened in a remote region of the Congo with headhunters and crazy killer monkeys I would not have even tried it!

Cheers

[Resasi]

Paul think you might find there would be a consensus of opinion that the head hunter would have to be nibbling your neck, the cannibal have his teeth fastened to your ankle and the killer monkey???? be trying to put a headlock on you before you, or anyone, should even consider taking that thing off the ground.

There shouldn't have been any test or evaluation.

Fact it held together proves what? That two guys got lucky?

[EI-GYRO]

If these are composite blades, it might be useful to cut cross-sections of the
distorted sections to see how the composite structure absorbed the damage.

Given that the blades would never be put back into service in that condition,
it is difficult to see what the 'experienced pilot' hoped to achieve by 'testing' them.

[Mike Schallmann]

Minigun man --to quote you


"Blades and rotor heads are tougher than you think. Perhaps the pilot did take a chance on flying bent blades but I would imagine he or she took there time bringing them up to speed and hopfully flew in GE for a while before climb out. The fact that the pilot and gyro are in once piece proves the structural intergrity of both"


This is your statement--IMHO it implies that the test pilot used good judgement and knew what he was doing -this is totally absurd! ANY competent pilot would NEVER fly an aircraft that had major structural damage--

Also since it held together you implied it was structurally sound--again that ia an absurd comment.Structural integrity had absolutely been inpuned -it quite simply had not reached the point of catastrophic failure.

Composites when deformed to that state have delaminated and sheared between plies-also excessive stress has been applied to the spar--just because you dont know or understand this does not negate this--You imply a knowledge of composites and aluminum stress analysis as they pertain to rotorblades that is inconsistent with actuality.


Yes I'm busting your chops--but the statements and implications you have made are not what I would consider appropiate decisions for flight.If you disagree with this ask any FAA Inspector for his opinion of the incident--had an inspector been present the Aircraft would have been flagged as unfit for flight--

If you really believe that your statement is legitimate and reasonable then you should IMHO re-evaluate your attitudes and abilites to make reasonable decisions-as they pertain to aviation--

I really dont like making these type of posts but it is IMPORTANT-that we take flying gyros seriously and use sound judgement in our decision making process.












y

[Resasi]

Paul, for sure certainly wasn't lacking in imagination.

Congolese headhunters and crazy killer monkeys.:eek:

:peace:

[gyro]

Mike, you still not comprehending my post.....and you drawing your own conclusion by twising up what you think I mean. If this statement that I made is your stumbling block let me clarify. "The fact that the pilot and gyro are in once piece proves the structural intergrity of both." I was referring to the rotor head and blades. not the pilot.

did I not say replace the rotors and inspect the other crutial parts of the aircraft??? Did I not say he took a chance flying it?

Look Mike, sombody made a boo boo and whacked the blades and then sombody did a boo boo afterwards by doing some testing.

was this a good idea NO!!! did the rotor head and blades hold together after the fact? YES. does this mean he should keep flying it? NO. should it have been grounded? YES. I agree with what your saying and your just twisting things up thinking I mean otherwise.

I mearly looked at this posting as a WOW!!! how impresssive are the machines we fly to take a hit like that and keep ticking...That is all. ( my first post Implied, replace it, check it, fly it)

God forbid if Mike should have a rotor strike in the Congo!:boink:

[Resasi]

Whaaat??? With all those headhunters and killer monkeys... probably not likely to include it in his list of places to fly.

Sorry Paul busting your chops a little there, but that was an amusing scenario you cooked up, and I guess quite a stimulus to giving it at least a passing consideration.

[gyro]

Whaaat??? With all those headhunters and killer monkeys... probably not likely to include it in his list of places to fly.

Sorry Paul busting your chops a little there, but that was an amusing scenario you cooked up, and I guess quite a stimulus to giving it at least a passing consideration.

Hey, I figure we gota do what we gato do. It would have taken a pretty tense situation such as being chased by headhunters or those crazy monkeys to make me want to fly a damaged aircraft!!

[HMax23]

Cause of the rotor strike.

One of the posts in this thread indicates that this is due to rotor flap and has to do with technique.

What causes rotor flap and how is it prevented?

Eric

[jcarleto]

What causes rotor flap and how is it prevented?

There are a few things that may cause rotor flap. The short answer is too much wind through the rotors before they are spinning fast enough. It is a common error, but a bad one that can cause a lot of damage. You have to be patient on take-off and not apply throttle too fast or the forward speed will effect wind through the rotors at too fast a rate. This can also occur when trying to start rotors in high winds. Another common mistake is taxiing downwind after the blades are spun up and letting them get to slow, then turning into the wind with slow rotors...instant flap. A good rule of thumb is to keep your rotors above 80 RRPM while taxiing or if you cannot, then stop them. If you hand start rotors, minimize the time after you have the blades up and spinning and start over if they get too slow before you can fly.

It is important to unload the blades (put the cyclic full forward), power down, and possibly even brake the very moment a flap is detected. It is more important to learn to operate a gyro so you never flap your blades in the first place.

You'll know you have rotor flap right away. Even a mild flap may pull the cyclic from your hands. More than a mild flap starts bending and breaking things and can even topple a gyro. Blade flap can be severe enough to cause the rotor to hit parts of the gyro it shouldn't be able to reach under normal conditions. The flapping action in a severe flap has been known to cause the rotor to come into contact with the tail section. A bad day.

*JC*

[freebird]

Rotor flap is usually caused by trying to force air through the rotors faster than they can accept the load. This causes the rotors to flap and can strike the ground or your tail feathers. It usually happens when trying to take off.

Often after pre-rotation, the rotor is tipped back to catch the prop thrust.. If the rotors are not rotating fast enough or the prop is rev'd too high the air only hits part of the rotor disk and will quickly cause flapping.

A violent stick shake is usually the first indication and the pilot should force the stick fully forward and reduce throttle and/or prerotator action immediately.

[All_In]

Rotor flap is usually caused by trying to force air through the rotors faster than they can accept the load. This causes the rotors to flap and can strike the ground or your tail feathers. It usually happens when trying to take off.

Often after pre-rotation, the rotor is tipped back to catch the prop thrust.. If the rotors are not rotating fast enough or the prop is rev'd too high the air only hits part of the rotor disk and will quickly cause flapping.

A violent stick shake is usually the fist indication and the pilot should level the disk and reduce throttle and/or prerotator action immediately.

That's the best explanation I've heard, thanks!!

[bowns]

In my reading of the story,a pair of perfectly symmetrical distortions works better than two perfect asymmetrical ones.

[bpearson]

Like the MT03 the ELA's keel allows the nose to rise right up. I doubt it was blade flap, more likely the pilot went way back onto the keel.

No problem if flown correctly but like the accident in the UK recently I think this would need to be watched on takeoff.

Probably wrong!