R22 Hover Autos

[bladewashout]

An instructor in the US recently gave me some hover auto training in an R22, which is throttle off, right pedal, let it settle, pull up lever. Fairly simple... :hmm:

I failed to completely turn the throttle fully into the detente and when I pulled the lever the correlator increased the throttle enough to get the revs back into the governed range, the governor took over and picked up the revs. This led, of course, to unanticipated right yaw and lift. The ship bounced off 2 skids, yawed substantially, but the instructor recovered it and we tried again after my change of underpants, but he kept the governor on for the further training.

My question is: do instructors more commonly do this training with governor off? I can't see any real benefit of governor on - if you turn off the throttle at that height, you're going to hit the deck and the risks of having governor on are that exactly what happened to us will occur, and an R22 bouncing off skids is not a great place to be!
BW

[Whirlybird]

If you turn the governor off, the correlator will still increase the rpm if you raise the lever that much. In fact, I think it will do it more, since the correlator over-compensates if the lever is below 18 inches of manifold pressure.

It sounds to me like you raised the lever far too much. I teach my students that you really just have to hold the lever position, unless you started in a very high hover. More important, you need right pedal and right cyclic to prevent yaw and drift and land vertically. If you do that and hold the lever position, the helicopter should settle on to the ground with no problem.

I don't turn the governor off, and I'm not strong enough to get the throttle into the detente on some stiff R22s, but I've not had a problem teaching hover autos.

[rotorfossil]

Whirlybird: How do you teach normal EOL's if you can't get the throttle into the detente? Incidentally, it makes it easier to closer the throttle properly if you use cape leather gloves. Robinson throttles are too slippery for sweaty paws.Also if you are doing hover EOL's without raising the lever, you must be pretty low.

[Johe02]

I think it's extremely unlikely a lycoming piston engine will loose all power in the blink of an eye. Much more likely to lose a mag or drop a valve, splutter and cough and quit slowly.

So. . I try not to give the students the impression the engine is going to quit on them without them being fast enough to react.

From the hover, if you roll the throttle off (really slowly for the jumpy students) you can teach them to keep the 'all important' attitude with the cyclic keep straight with the pedals and encourage them that raising the lever will be the natural thing to do should they be descending to fast. .

It is also completely 'do-able' by a low ability student. . (helping their confidence)

Am I too soft. .? :)

[Ascend Charlie]

You mean "splutter and cough" like the cliche aeroplane in the movies?

It's not gonna happen in a chopper. Planes have the prop attached to the engine, which keeps the engine turning if it momentarily stops, and it might encourage the engine to fire up again and keep running, albeit for a short time. Hence the "Brrrrrtt .... brrrrrttttt...." of the movie engine failure. It also doesn't matter if the prop is forced to stop because the engine has siezed.

A chopper has the freewheel unit, which prevents the engine being driven by the rotor, so if it decides to suddenly stop, the only thing that will make it kick over again is you releasing the collective and turning the ignition key again. And that ain't gonna happen.

So, there probably will not be much sputtering, just one burp and it's gone.

And if Whirly can't get the throttle into the detent, how does she teach going for range in autos, pulling the revs down? Or controlling the revs in a turn during a 180?

[Johe02]

Well, if you're going to be picky about wording - please explain the mechanical process involved when a piston engine 'decides' to suddenly stop? And what causes it to 'burp'? Fizzy avgas? :}

Not saying it couldn't happen ever, just saying it's not very likely. The only thing I can think of would be a broken crankshaft.


Why would you need the detent to teach range autos or 180's , you just hold the throttle closed and control rpm with the lever. . .:hmm:

[Whirlybird]

I don't turn the governor off, and I'm not strong enough to get the throttle into the detente on some stiff R22s, but I've not had a problem teaching hover autos.

Please note the words SOME STIFF R22S. They do vary, and I have no problem with most of them.

Start fairly low to teach engine failure in the hover? Of course - are you teaching the student to hover at 10 ft? :confused: And at normal hover height, if you close the throttle, keep the machine straight with pedals and cyclic, you don't need to raise the collective very much - certainly not yank it up enough for the governor to kick in. That's my experience anyway.

For the record, I don't teach EOL's to the ground yet; I'm still an FI(R) and I teach them to the hover. When I get to the point that I do, then will be the time to worry about my weak wrists and SOME stiff R22s. That's if they don't change the rules so that you don't teach 'em to the ground anyway, which looks like becoming the case.

As for teaching range autos and 180 degree turns, as Johe02 says, why would you need the detente; you use the lever. :confused:

[kissmysquirrel]

Detent for Range Autos? That's a new one on me!!:confused:
Just make sure to keep the needles split with throttle. Some people actually prefer to keep eng revs slightly higher for eng. management.

[rotorfossil]

Whirlybird. Helitrainingcom 1/2005. "Instructors should teach the full range of EOL's with the students following through". On the skills test as a minimum the students should do a flared recovery to the hover. It doesn't say FI/R's should not do normal EOL's, or is this a local policy?

[Whirlybird]

It's been the policy at every school I've been at, as either student or instructor, that less experienced instructors don't do engine-off's to the ground.

[ascj]

Although i'm not an instructor there are a few points here i think are worth talking about-

Blade washout - You must have let go of the throttle or not held it firmly enough for the Governor to take over. Don't freeze on it but hold the throttle firmly and you can over power the governor. The good point about leaving it switched on is that if it all goes bad (hopefully not in a hovering auto, but a good habit for Auto practice for later) then all you have to do to get engine RPM back is let go the throttle (but watch for the overspeed) and the machine does make life easier. As long as your Rotor RPM is above 80%.


Whirlybird- If you turn the governor off, the correlator will still increase the rpm if you raise the lever that much. In fact, I think it will do it more, since the correlator over-compensates if the lever is below 18 inches of manifold pressure.


The correlator is mechanical. It is the coning of the blades that causes the overspeed just like an ice skater tucking themselves in to spin faster.

certainly not yank it up enough for the governor to kick in. That's my experience anyway.

The Governor wont 'Kick in' from yanking the collective its driven by the rotor RPM.


Johe 02- I think it's extremely unlikely a lycoming piston engine will loose all power in the blink of an eye. Much more likely to lose a mag or drop a valve, splutter and cough and quit slowly.:eek:

Run a machine on a pad and turn the fuel off then come back and tell us all the results. They dont cough hey! Some other ideas for it justto stop are besides fuel starvation, Water in the fuel or a simple blokage, an oil line breaking leading to engine siezure...


Well i've got to go What do you think

[Johe02]

Thanks for clarifying those points, you do sound like you know your stuff.

But as far as my point goes: (ok forget I said 'splutter and cough') I still maintain it is extremely unlikely the engine will fail as if you switched off the mags or snapped the throttle closed.

Not saying you would have time to chat. . 'is that the engine failing? oh yes I think it is' . . . but almost immediate power failure.

Water in the fuel? - Not saying it couldn't happen.

'Simple' blockage?

Even an oil line breaking would be unlikely to cause this at normal operating temperatures. Not to mention the oil light warning

Turning the fuel off on the pad would not replicate running out of fuel.

I guess I'm talking about a probability factor :8

[ascj]

Johe 02 Sorry mate i didn't explain myself very well as i was running out of time. The 'simple blockage' that i was thinking of was a bit of paint from the inside of a 44 gallon drum. Fortunatly the pilot (not me) put it down without any damage, not even to his pride. But the pilot commented that it just stopped. Maybe this isn't a problem in england, do you ever fill up from a drum?
I got the same story from another 5000 hr pilot just three days ago (the story was a couple of years old) "the engine just stopped? I still don't know why." :eek:
Water in the fuel? It can happen I know someone wo still has a sore back because of it. No coughing either (the engine that is).

Your right about the oil line though that was a bad example i'd like to think that one of the three warning systems (Are we still talking R22)would be picked up by the pilot.

One more to be aware of though is the belts coming off if the sheaves haven't been lined up correctly. Apparently the engine takes off and the blades don't. This is very very unlikely.

These stories are from the last ten years. And I believe your right about the most likely problem being a Mag failure (personally saw three last year. I was only a pax in one) or a valve problem (only heard of one in my area in the last year). The engineers tell me by the way that the valve issues are caused by not cooling the engine down or warming them up correctly. And if treated correctly the engines in the 22 is bullet proof so to speak.

As for turning the fuel off on the pad I'm still yet to see it personally but i'm led to believe it just stops no spluttering. I'm going to have to try it before i can be sure but unless i've been lied to... I'll get back to you on that one. I know it's not the same as flying but i'm guessing that with less load on the engine than the engine would run longer before stopping.

My point is that while the engine stopping stone cold dead may be a small probability it is still a possibility and one that shouldn't be discounted.


Safe flying ascj :ok:

[rotorfossil]

Whirlybird: The difference between FI/R and FI should be INSTRUCTIONAL experience. The handling skills should be there before starting the FI Course. OK, this seems to a be a quaint notion these days, but that was the original idea, which seems to have got lost along the way. How do FI/R's acquire the skills if they don't do all the manoeuvres.
I suspect we are seeing the results of PPL/H's not being taught EOL's properly, which leads to a domino effect through CPL/H's to FI/R,s. Result - everybody thinks that they are difficult/dangerous, which they are not if taught by competent instructors who have self confidence in their abilities. Doing EOL's per se is not the whole point. It is to do with pilots having confidence in their abilities to handle the aircraft in all corners of the flight envelope. I despair a bit when I read stories about the alleged difficulty of manoeuvres. Even autorotations seem to becoming a big deal when all they are is a means of descending, outwith the emergency situations. End of rant! I know that I'm not going to change the world.

[Johe02]

Never fill up from a drum at the flying school but that would increase the probability factor. .

Overall, I can't say you are wrong - just trying to keep it real. . I don't want my students getting so stressed about the fact they won't be able to control a sudden engine failure in the hover that they make a mess of something else.

Rotorfossil - I would guard against telling people what they should be able to do. It might be tempting for someone to show you that they can do an EOL when perhaps they are not quite ready.

Whatever your rating, at our school it's the boss that decides who can do EOL's to the ground. Fair enough I think.

[JonWhitehouse]

Question for me would be how a newly unrestricted FI could perform, let alone teach, these maneovers safely when they're not allowed to whilst still FI/Rs, but as you say, its descretionary.

[Bullitt73]

When it comes to the statement "the engine just stopped" that's a very open statement. I guess since we are talking about hover auto, 1 second is a long time. One of my instructors who had a lot of experience told me that most likely the engine would quit like you just slowly start to roll off the throttle all the way in a firm way. Should take about 1-2 seconds to roll it off. Then you have the instant snap off, which is to roll off as quickly as you can. Also much more tricky to catch. :eek:

When I instructed I just to start with the roll off firmly, and then gradualy faster until it is done in a fast snap. Also good to vary between them, because I assume every engine failure is different :)

Don't understand how Govenor on/off is a problem? I always leave govenor on. If engine kicks in, means you haven't closed the throttle enough.

Highly recomend to use gloves in the R22, makes life much easier.:ok:

Cheers