Autorotational question
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Fair enough. I thought maybe some people had tried it at the upper and lower limits of RPM and may have seen some difference between the two as it related to the touchdown.
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Every helicopter AFM will have a best range Indicated Airspeed / RRPM combo same as does every fixed wing have a best glide speed and propellor setting when the donk stops.
Just learn to go for it automatically first while finding a spot (oh yes you should already have a spot in mind with your mind and eyes in continual, where will I go now mode) and yelling for hellup, otherwise you might miss that - onespot.
Aim to recover by three hundred AGL for the final run in best auto speed /RRPM if possible. Try also to have as long an approach as possible in a straight line so that excess energy is not being used up in turning, which of course will speed up the ROD.
Minimum ROD is life with the collective on the bottom, everything else I believe is second preference.
Just learn to go for it automatically first while finding a spot (oh yes you should already have a spot in mind with your mind and eyes in continual, where will I go now mode) and yelling for hellup, otherwise you might miss that - onespot.
Aim to recover by three hundred AGL for the final run in best auto speed /RRPM if possible. Try also to have as long an approach as possible in a straight line so that excess energy is not being used up in turning, which of course will speed up the ROD.
Minimum ROD is life with the collective on the bottom, everything else I believe is second preference.
Last edited by topendtorque; 24th Jul 2012 at 11:41.
Did a lot of precision auto's years ago, spent hours playing with airspeed and rotor rpm, mostly UH-1/AH-1 airframes. My conclusions were that maintaining the rotor rpm in the 100% range throughout the flare resulted in more effective and controlled deceleration and touchdown, allowing the rotor to build to the high green (or limits) resulted in a less effective decel (with respect to rate of descent) that was not offset by the increased RPM for cushion. Disclaimer: this is just one person's experience in a highly unscientific test. Some might call it a "sample of one". YMMV
Coning in the flare. You may not be getting all of the lift you had hoped for with that Nr increase when that load is put on the rotor disk during the flare, but the decel is worth it. 
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This is a great thread, very interesting stuff, having recently completed an LPC on R44, I timed a standard auto from 1000' - from lever down to touchdown it was 46 seconds. This was obviously an intentional EOL, in ideal conditions, with the added security of an instructor by my side, an airfield on the nose, and an entry from the cruise, at an ideal speed. Still this 46 seconds passes by at an alarming rate. I often wonder what I would actually do if I did get an proper reason to complete an EOL with my family on board in not so ideal conditions.
I would be interested in hearing from pilots who have been in this position.
I would be interested in hearing from pilots who have been in this position.
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I often wonder what I would actually do if I did get an proper reason to complete an EOL with my family on board in not so ideal conditions.
I.E. Taught technique will rule.
The point about the correct auto RRPM where the design engineer, the test pilots and their maintenance manual says it orta be, I cannot stress loudly enough.
Let's say your rotor tacho has failed, you are still a little distance from your - land as soon as possible airfield where you can get it fixed - and the engine subesequently fails. As I have said before, you will first peer at the tacho, your heart will miss a beat or three, then you will remember, the auto RRPM is correct all I need to do is lower the collective to the bottom and the RRPM will settle in the green where it is supposed to.
Your instructor should have also covered your tacho in a long auto descent or three to ensure that you will quickly remember the "sound" of everything good. See - easy, time to pass the biscuits.
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topendtorque
Not sure that is always a good idea. Depends on your airspeed. In the cruise at 120Kts for example, dumping the lever could have negative G consequences.
Just make sure that your instructor ensures that you can / will put the collective down straight away the engine stops,
Chopjock, when you lower the lever, the nose will drop so a certain amount of aft cyclic is required just to maintain attitude - if you slam the lever at the floor at 120 kts and coordinate the entry by flaring gently then negative G will not be an issue.
Remember, in order to recover low Nr then flaring and turning will load the disc and help to regain those vital RPM.
Remember, in order to recover low Nr then flaring and turning will load the disc and help to regain those vital RPM.
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Just remember why we are following the "normal" procedures during autorotation pratices:
To establish some kind of "reflex" when the engine quits in real life.
In most cases, you will not go for a standard straight in auto out of 750/1000 ft AGL, but you will find yourself in a position where you have to turn/extend or shorten the glide.
So stop discussing about what would be "easier"-and do, as the instructor said, because thousands of pilots have been doing hundredthousands of autos that way-and some of us had to prove that they can do it in "real life", too-and it worked for most of us.....
To establish some kind of "reflex" when the engine quits in real life.
In most cases, you will not go for a standard straight in auto out of 750/1000 ft AGL, but you will find yourself in a position where you have to turn/extend or shorten the glide.
So stop discussing about what would be "easier"-and do, as the instructor said, because thousands of pilots have been doing hundredthousands of autos that way-and some of us had to prove that they can do it in "real life", too-and it worked for most of us.....
