Greenvalley285 Posted March 17, 2017 Report Share Posted March 17, 2017 During practice autorotation in Huey, while doing according to checklist, Throtle is rolled to idle position. So we expect to Idle RPM on N1 gauge, and that is 68% to 72 %, so correspondingly, where should be N2 (Power turbine) on N2/NR instrument gauge. It should not be at 6600 RPM, rather less then it. But then where it should be...? 6000 or 5800 or what.As soon as the throtle is again full open, N2 should goes back to 6600, and join with Rotor Needle. Quote Link to comment Share on other sites More sharing options...
iChris Posted March 21, 2017 Report Share Posted March 21, 2017 It should not be at 6600 RPM, rather less then it. But then where it should be...? 6000 or 5800 or what.As soon as the throtle is again full open, N2 should goes back to 6600, and join with Rotor Needle. What's the problem? Are you getting a needle split? With N1 @ 72% an, unloaded N2 (rotor in autorotation) could run 6000 - 6100 RPM. What you should be concerned with is your rotor RPM in autorotation, within correct range, per maintenance manual. 1 Quote Link to comment Share on other sites More sharing options...
Greenvalley285 Posted March 22, 2017 Author Report Share Posted March 22, 2017 What's the problem? Are you getting a needle split? With N1 @ 72% an, unloaded N2 (rotor in autorotation) could run 6000 - 6100 RPM. What you should be concerned with is your rotor RPM in autorotation, within correct range, per maintenance manual. Yes, my confusion is over now. During practice autorotations, we must be looking for Rotor needle, NR, where it is. No concern that where is N2 needle. Split of N2/ NR is manifest that, Clutch is working properly. Regards Quote Link to comment Share on other sites More sharing options...
AS350 pilot Posted March 24, 2017 Report Share Posted March 24, 2017 Interesting question! Glad you got it sorted out. It's surprising how that machine auto's....you would think it would auto great; but it really falls like a brick! The 206 (which I think pretty poorly of) auto's great and the 205 / Huey (that I really like) auto's poorly. Quote Link to comment Share on other sites More sharing options...
Knightsix Posted July 17 Report Share Posted July 17 I completed Army Flight School early 1968. I arrived in Vietnam in time for the Tet invasion of 1968. I flew 1,955 combat hours in Vietnam and was shot down five times during the 18 months I was there; safely autorotating into hot LZ rice paddies or jungle environments. I was qualified to fly virtually every model of UH-1 A/B/C/D/ and H (I flew the D model on arrival, quickly replaced by the H - I also flew the "C" model gunship). We were taught by the finest Vietnam combat pilots during our flight training stateside. I learned how to autorotate a UH-1 helicopter in every orientation possible short of upside down. EVERY autorotation was all the way to the ground...something NOT taught to today's helicopter pilots which, in my opinion, is a terminally stupid thing to do. "Simulations" will never replace actual experience. The Bell UH-1H (Bell 205) was an autorotation monster - meaning it was safe and always 100% controllable in every orientation (I loved "Spot" autorotations - fantastic fun and quite the super fast elevator ride!). On a mission in Vietnam, I was asked by my copilot if vertical autorotations were possible? I took us up to 5,000 feet and confirmed hover with all crew members. I then dropped the collective, split the needles and down we went - a 100% absolutely safe and controllable vertical descent to 2,000' at which I simply pushed the cyclic slightly forward and recovered collective. I have safely performed 'Hammerhead Stalls" (cyclic climbs) numerous times (a vertical climb "nearly" straight up and tight pivoting turn at the top with vertical descent). I say "nearly" as it's the disc that flies and while it appears "straight" up we're actually shy of that attitude. I use off-power pedal to spin us around just short of stalling and carefully pull in cyclic to regain level flight while ensuring airspeed remains below VNE - a very "showy" maneuver. NEVER lower the collective at any time - the rotor system must always have positive G throughout. I can personally attest to the fact that a UH-1H will in fact turn tightly at MORE than 90° of bank - especially if the pilot (me) has just been lit up by enemy radar-guided anti-aircraft fire due to a flight leader's navigation error! I could go on, but I believe I've made my point. The Bell UH-1H helicopter is a fantastically capable machine and in "TRAINED" hands is a joy to fly! 1 Quote Link to comment Share on other sites More sharing options...
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