Autorotation
Just to stir the paint ...i would like to be pedantic and say you can enter autorotation without losing ANY height , let alone 2-300 ft , you can in fact GAIN height during the process. So na..na...nana...na...ya ...boo....sucks .
end of contest , i win.
end of contest , i win.
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AA - you have given me a headache!!
GAGS
E86
PS. NH you might like to explain yourself a little more clearly - yes you can cyclic climb whilst lowering the lever post engine failure but a descent airflow is required upwards through the rotor system to establish the aerodynamic forces to sustain the rotor RPM.
PPS. Or am I wasting my time Crab!
GAGS
E86
PS. NH you might like to explain yourself a little more clearly - yes you can cyclic climb whilst lowering the lever post engine failure but a descent airflow is required upwards through the rotor system to establish the aerodynamic forces to sustain the rotor RPM.
PPS. Or am I wasting my time Crab!
Last edited by eagle 86; 11th Dec 2007 at 04:58.
AA -do the terms coherent and lucid mean anything in your world?
if not I'll have a pint of what you've been drinking!! Keep taking the medication....
Eagle - I think Nigel is talking about a zoom climb entry to auto, the sort of thing we used to do from 120 kts in a Gazelle, you could gain 2-300 feet if you were gentle. I think the initial maintaining of the Nr is due to flare effect - in fact if you lowered the lever too much you would overspeed the head - once you select a speed stable attitude the RoD starts to build and then you are fully in autorotation.
if not I'll have a pint of what you've been drinking!! Keep taking the medication....Eagle - I think Nigel is talking about a zoom climb entry to auto, the sort of thing we used to do from 120 kts in a Gazelle, you could gain 2-300 feet if you were gentle. I think the initial maintaining of the Nr is due to flare effect - in fact if you lowered the lever too much you would overspeed the head - once you select a speed stable attitude the RoD starts to build and then you are fully in autorotation.
Yes crab , i am , but by the time you have levelled off i would say you are in autorotation .....feels like it anyway ....and i reckon you could land at a higher point than where you lost power. ie if you were zooming down a river canyon, low level, you could lose power and still climb and land safely. ( i accept you would have to be very on the ball to do it !!) so my point is that i believe during the cyclic flare the aircraft can establish itself in auto.
Certainly crop spraying you could have a donk stop at 10ft and 50 knots and climb, flare and land safely ...but that may be a different thing .....
Certainly crop spraying you could have a donk stop at 10ft and 50 knots and climb, flare and land safely ...but that may be a different thing .....
Nemo Me Impune Lacessit
Well I only ever had one real engine failure during flight and any idea that you might 'zoom' climb after the failure whilst the speed drifted back would have been a joke. It was a catastrophic failure of the compressor and happened so quickly that the yaw, when corrected, had the airspeed back at 70kts and by the time the vital actions and a Mayday had gone out the IAS was stabilising at around 50kts.
Seen many fine demonstrations of the 'zoom' climb but in reality you may not have that opportunity.
Seen many fine demonstrations of the 'zoom' climb but in reality you may not have that opportunity.
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There was discussion of doing hovering engine failures in an R-22 at heights of up to 12 feet, involving lowering the collective before pulling pitch to cushion the touchdown. This was followed, quite correctly, by discussions that indicated the posters didn't think that anyone would react quickly enough to an engine failure at that height to be able to lower the lever first before raising it.
Quite correct - and that's why the low hover point of the HV curve is demonstrated by only allowing the lever to be moved up. No down movement first is permitted in determining the low hover point.
From experience in demonstrating this (albeit in the 206) many times to budding test pilots, and having had one (self-induced) real engine failure I can assure you that this height is a very realistic height. Hover above this height at your peril - in all probability you won't react quickly enough to do anything except cushion the touchdown.
Quite correct - and that's why the low hover point of the HV curve is demonstrated by only allowing the lever to be moved up. No down movement first is permitted in determining the low hover point.
From experience in demonstrating this (albeit in the 206) many times to budding test pilots, and having had one (self-induced) real engine failure I can assure you that this height is a very realistic height. Hover above this height at your peril - in all probability you won't react quickly enough to do anything except cushion the touchdown.
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Shawn, at the risk of going off-topic: Along the same lines as your experiences with non fadec torque limiters, is there an arguement here for an automatic collective system? Again it is the thought of the collective obeying the pilots intentions rather than inputs (a TP will likely understand what i mean by this).
What i am thinking about is a system which will have already positioned the collective correctly for entry to auto before the pilot even recognises the engine problem. It could be based on N1/2 and Nr, and could have two or three sensors and channels to avoid a single point of failure. There is nothing to stop this system also altering a raised collective input for overtorque to keep the Nr at most efficient %.
The system could be the usual SCAS arrangement of parallel and series actuators, to control shape pilots input. Most of the time it would not alter the input, but when the situation demanded it it would provide just the right adjustment...
What i am thinking about is a system which will have already positioned the collective correctly for entry to auto before the pilot even recognises the engine problem. It could be based on N1/2 and Nr, and could have two or three sensors and channels to avoid a single point of failure. There is nothing to stop this system also altering a raised collective input for overtorque to keep the Nr at most efficient %.
The system could be the usual SCAS arrangement of parallel and series actuators, to control shape pilots input. Most of the time it would not alter the input, but when the situation demanded it it would provide just the right adjustment...
