Hi guys,
FWIW:
a) If I remember right from the last 2 safetycourses, the 1.1 sec figure is only true IF you want to "keep speed + altitude the same as before the power failure".
You loose all power, you immediately will start to slow down and start to sink if you do nothing. So here you already got some time coming towards you.
IF you really wanted to keep v+h you would have to get some forward cyclic and collective INCREASE at the same time, then of course everything is over in 1.1 sec,
b) The suggestion in the safetycourse was " to apply gentle aft pressure on the cyclic to maintain the nose more or less level. Basically don't let the helicopter accelerate."
While "gently" applying aft pressure you also would want to lower the collective
.
c) "Slamming down the collective!" This is a no-no!!
Slamming/snapping down the collective does nothing good - it will only get you towards a low-g situation (which in an auto is not as bad as in a regular push-over, but....).
All you will do is go nearly through the roof!
Correct action is to lower the collective SMOOTH and QUICK, but please don't slam it. Give the rotor some time to change the airflow!
back to b) The faster you fly when 0-power hits, the faster Nr will decay. Worse yet the faster you fly the more inertia the helicopter will have (the whole machine, NOT the blades!), which means it will not want to really start to decend, but keep going straight (I think that Newton-guy found that out some time ago...)
So back to the safetycourse (and reality), if you are fast it will take some time to get a decent decent rate. Now as we will need something to convert to maintain Nr, the only thing we have for the moment is speed.
So if you would like to keep up Nr in the comfort range you will HAVE to do a "GENTLE" flare, produced by the "GENTLE" backpressure on the cyclic.
Those who attended the safetycourse will remember the graphs that showed the amount of energy you get from decelerating from higher speeds towards 60 kts - V2(squared) does magic,
However it is very important to not overdo this as you can maintain altitude perfectly well nearly all the way down to 25-30 kts by flaring hard enough. Only you have nothing left to convert if you are at some serious altitude at this point.
The idea is to just hold back enough (decelerate) to keep Nr happy until the decent-rate is good enough to start milking altitude for energy.
With enough practise you can do throttle-chops (not recommended by RHC or me) at 90 kts and never hear the low rpm-horn (98%) until the level-off at the bottom of the auto.
"With enough practise" is the key-word!!
When I do occasional pre-solo checks, all I really care for (in the auto department...) is a correct AUTOMATIC reaction from the student if something goes towards low Nr. And mostly they are surprised. After a couple of real entries they seem to asimilate the idea.
You can't expect a student to be perfect when going for a solo, especially in a R-22 and around 20 hrs total time. All I care for is that they are able to get into a stabilized auto. At the bottom they will do something and most likely they will walk away in the unlikely event.
I don't usually chop throttles, but I will start to roll off power slowly to get the low rpm horn. After a couple of trials the reaction becomes automatic. Smoothly lowering the collective and SIMULTANIOUSLY applying "GENTLE" backpressure.
At this time we are not practising perfect autos (1-2-3 lower collective and roll it off) but reaction to the unexpected.
Mostly I start to roll the throttle towards low rpm on the way back to the hangar a couple of times too, and things get more relaxed all the time. Most students even start to react before the warning horn comes on (just hearing the change in rpm) - collective starts to go down smooth and cyclic starts to apply back pressure ever so subtle.
Remember not all low Nr is because of a power failure: Some students and "done" pilots are nervious and grip the throttle too hard so the governor can't do its job - reaction should be the same.
As mentioned the R-22 is not going to pardon slow reaction time, so it is a basic requirement to get your reactions to any changes in Rotor-sound and/or Engine-sound AUTOMATIC, like putting your foot on the brake pedal if you see something unexpected in front of you on the road. You might not want to brake after all, but you want to be ready - AUTOMATICALLY.
Don't blame the machine for your lack of practise or wrongly learned maneuvers!
d) "Increasing rpm in turns" This happens mostly because of deceleration in the turn. Try it out, concentrate on keeping that 60-65 kts in the turn and your rpm hardly moves! Decent-rate will increase some, but will also come back when you straigten out. While maintaing your speed the nose will go a little low too, but rpm will hardly move.......keep it at or below 30º bank too!
You don't have to fly the R-22, constantly awaiting desaster, most likely it will never happen. Just spend some quality-time with your instructor practising autos/reactions/etc.
"You shouldn't feel right if you didn't practise at least 1 auto everytime you are out flying!
" Autos should become fun to do, not a dreaded necessity.......
("1 auto everytime out" is mainly aimed at low time pilots, I understand that in the commercial world this will mostly not be possible. Also for low timers this should be done with your safety-course equipped CFI!!)
Just plan for some 15 min extra and do some quick-auto-warm-up with your CFI. Then kick him out, get your pax and go fly!!
Cheers,
3top,
PS: I did the "GENTLE" thing repeately and on purpose - It is very important! I don't like big stick moves!! Helicopters want as little movement on the controls as possible and if you do, you actually want to think about "applying pressure" rather than moving - whatever you do, do it smooth, no need to snap the controls anywhere ever and once you're done quit stirring the fuel...........