Emergency training - controls stuck

[Fun Police]

since there were many good replies to fhvn4d's thread regarding autorotations, i thought that i might put this to you guys:
a few days ago i was chatting with a friend who is moving to a new company and part of their training is dealing with stuck collective and stuck cyclic.
i can see dealing with a stuck collective by running it on to a strip (or somesuch) but a stuck cyclic?
this company operates pretty mcuh everything from 206's and up so i'd expect that the training will take place in a 206.
any thoughts?

[800]

Basically, with any stuck control you end up using "secondary effects of controls".
Most people may not have done this since they did their flight training.
If you cannot free the jam (stuck) control, you would go through a series of control checks. ie use the controls that are not stuck to check the secondary effects of these controls on the aircraft itself. You can then test the landing confirguration.
A bit harder in larger aircraft, but in a training aircraft (R22, H300, B47), practicing a stuck cyclic you can try to change the C of G by learning forwards or backwards and by learning sideways etc. It takes time but you can get some movement and thus some attitude change.

[Flingwing207]

I would think that the chances of an actual stuck cyclic would be pretty remote, so it makes this training more of a correlation exercise than actual emergency procedures training. I will say that I would have put stuck collective in the same realm, but oddly enough I've experienced it. :bored:.....:confused:.....:eek:

[fhvn4d]

you know, i have to say this is a great question... i noticed that nowhere in my preflight do i check linkages and such for cyclic until im already @ RRPMs that would almost allow flight. i mean, we do a cakemixer check of them when we first get in but dont actually get down on the floor and look at the mechanical linkages that are held in with what looks to me like cotterpins. im talkin an s300cb, and when i move the pedals aft, so i can reach em, i make a point to at least LOOK at the control linkages and make sure something didnt flop out of the cupholder and get in there to limit movement.

[jab]

Flingwing207, tell us more about the stuck collective episode, I would like to know more. Have never heard of it happening before.

[Thomas coupling]

Stuck collective - by all means. A practical situation requiring some form of training.

Stuck Cyclic - get real :{ You'd die very soon after. You certainly wouldn't have time to go through an emergency procedure. The moment it jams in a position anywhere away from the trimmed level position - that a/c is going to lean in that direction, more and more and more...... until you are out of control completely!
How can anyone teach a jammed cyclic??

[After thought: maybe, just maybe a helo with full autopilot and the cyclic trimmed for S and L might make it on a wing and a prayer.]

[the coyote]

I seem to remember a few years ago in Oz, an S76 had some sort of stuck cyclic. I heard the pilot had to run it on at high speed as they couldn't slow it down. Don't quote me, just a vague memory.

[vaqueroaero]

Stuck collective - fairly easy to recover from and practice. Get on the backside of the power curve and down you come.

I remember a few years ago a solo student in a 300 had not buckled up the passenger side seat belt. It got stuck at the base of the collective rendering it imovable. When he went to lower the collective to descend, sure enough he couldn't lower it. He eventually found out what the problem was and came home.

A stuck cyclic though? Haven't got a clue.

[212man]

I agree with TC: a genuinly stuck cyclic will kill you; a bit like double hydraulic system failure in a heavy aircraft. If its a restricted movement, then there may be some possibilities, like the high speed run on mentioned later.

Jammed collectives are a real possibility when there are other 'gubbings' in the linkage. The bell 212 has a 'mechanical fuse' (or weak link) that you can pull through, and break, in case of a jam in the doop compensation/N2 beep linkage. You'll end up with varying Nr with collective, and the Nr beeped to maximum, but at least you can still operate the collective.

[Whirlybird]

Stuck collective - fairly easy to recover from and practice. Get on the backside of the power curve and down you come.

Does this work? We practised this on my FI course, and it didn't seem to. I was asked what I'd do, and said the same as vaqueroaero - but I tried it and we didn't really come down, or not much anyway. Mike Green showed me what he'd do - he closed the throttle a bit, at the same time putting the helicopter into a turn to raise the rpm. This brought us neatly down, turning in circles, adjusting throttle and turn as we went. I know we levelled out and did a run-on landing, but I can't remember exactly how...and early on a Sunday morning I don't feel like working out the theory; anyone know?

[fhvn4d]

strange idea.... trim it out ???? i mean i dont know **** being a student still, but in the sweitzer it seems you could get away with some pretty significant movement with the trim tab. maybe enough to get you home anyway???

[havoc]

One of the pilots here has a story about flying a BK and getting a blocked cyclic. He said this started at 1000 ft agl and of course no good place to end up at.

As he described it was caused by a book that somehow slide from under the pilots seat and wedged behind the cyclic and the flooring. This was an EMS version and I am not sure the how the book got there in the first place.

The only thing he could do was apply forward cyclic. In his trouble shooting he each time he moved the cyclic he had less aft travel available. Now in a shallow dive he found the trouble, gave forward cyclic and kicked the book
with his foot. He said he started his climb at tree level.

His rendition is much better with the superlatives and the visual effects.

[rotorfloat]

On the 206, I was taught, and subsequently teach others, that during the pre-flight inspection to check the direction of one of the bolts that go through the mixing lever on the collective rigging up to the swashplate. I guess if the bolt is in the wrong direction the remaining portion of the threaded end can bind with something (can't remember what right now) when the cyclic and collective positioned 'just so'.

[MightyGem]

I would think that the chances of an actual stuck cyclic would be pretty remote
Probably, but remember the gazelle last year with the harness box jamming the cyclic?

Does this work?
Yes, but it will depend on the power setting. It needs to be below hover power, then you can raise the nose allowing the speed to fall. Obviously the aircraft starts to climb, but the rate of climb will eventually reach zero and you start going down. Then it's a problem of balancing speed ROD and reaching your desired landing area: not easy. But, as Mike Green showed, there's more than one way to skin a cat, especially if you have a manual throttle.

[Flingwing207]

Flingwing207, tell us more about the stuck collective episode, I would like to know more. Have never heard of it happening before.
More accurately a stuck throttle-actuation bellcrank - the collective would move up and down, but throttle butterfly wouldn't close, so reducing power would run the RPM out of the green. Got the aircraft to the ground with the RPM a bit high and the collective up a tad, cooled the engine as much as at would cool, then pulled mixture (got some strange looks from my partners in crime all the while).

It turned out that at a prior inspection, a plastic cover between the seats had been installed improperly, eventually jamming the throttle bellcrank where it leaves the collective/corrolator.

So not exactly a stuck collective, but as near as I ever hope to see! :ooh:

[vaqueroaero]

Whirlybird, and anyone else interested.
Here's what I do in the 300.
The first thing is to decide at what power level the collective has got stuck at. Are you at hover power or cruise power or somewhere in the middle?
I'll start off with cruise power. If you bring the cyclic back to lose speed then obviously you are going to climb initially. If gaining altitude is no problem and there's no airspace above you then go for it.
If you cannot climb from your present altitude then by increasing your speed you will descend. Then once you are lower then bring the speed back to zero. Once you have lost all the airspeed you will start to descend. It may be necessary to reduce throttle as well. The 300 will fly quite happily with the engine rpm below the green. Obviously be very careful where the rotor rpm is.
If you are descending vertically then also be very careful of vortex ring. It can get quite interesting sometimes. As you approach the landing area then control the descent rate with engine rpm and by picking up a bit of speed again. Once close to the ground I control the descent purely with engine rpm and then do a low speed running landing or a take it straight to the ground.
At hover power I lower the rpm out of the green and you will get the same result. Remember not to be in a hurry as it can take a while to start descending. At the slightest hint of trouble abandon what you are doing.
If I am sitting in the left hand seat (300C) then I will put the friction on the collective, but obviously keep my hand on it at all times. It takes a bit of practice to get it right, but eventually you can land it no trouble at all.

[KikoLobo]

And this was from a friend of mine, who was flying a kit aircraft, it was an Exec helicopter, although i would never thought that someone would tech this, this is what happened.

He was flying along when suddently he was unable to turn left, but other than that, the cyclic was free, so he end up using pedals and right turns only to lign the heli to a field and landed.

His left cyclic movement was jamed with a screw that sets the stop points, this screw got loose and unthreaded and eventually disturbed any left movement at all...

I have never flown a heli like this, but this really happened. And for sure you wont practice this since its imposible to predict what would happened, and he only fly the machine and nothing else with whatever control he got left, and it wasn;t hard at all as he says, it was just nerve breaking not knowing what was causing it and if it could get worse, so he stoped fighting to get the left movement, and use right turns and pedals and that's it...

Just a thought. :), but it really happened to a friend of mine.