Originally Posted by
SLFool
It will be interesting to see comments from people with real world experience.
Complete engine failure, Bell 206 (belonging to Team Lotus founder Colin Chapman) in September 1980, flying at 120kts (approx.) at 900ft (due to low cloud). We were on our way to Imola in Italy (the only year the Grand Prix was not hosted at Monza). PPRuNer TRC, accompanied by the late great John Ackroyd-Hunt, flew to Norfolk within two hours of the incident as part of the post-engine failure response/rescue.
My godfather was engrossed in the business of unfolding maps when ..
- There was a kick in the aircraft's yaw
- I heard the engine wind-down
- The engine-out caution warnings illuminated and sounded
- My godfather let loose of his maps and assumed control of the aircraft
The response to autorotation was something of a joint venture in that in the second or two which passed between feeling the aircraft yaw, to the moment my godfather assumed control, I was already applying corrective rudder and making cyclic adjustments to maintain a level attitude. These adjustments happened instinctively .. you could perhaps say 'automatically' in that my hands and feet were actively 'engaged' with cyclic and rudder so that when the aircraft's profile was affected by the loss of power, it was 'natural' to correct them.
As my left hand was on my lap at the time of the engine failure .. and given my godfather's 'lightning' response .. he was the one who initiated the reduction in collective .. but, as it happened, an adjustment to cyclic input took place fractionally before he lowered collective and which, as I say, was instinctive in that the 'natural' response (when flying by visual reference) to an uncommanded change in attitude (at least for me) was that you instinctively sought to correct this.
My godfather went on to perform what I can only describe as being a 'perfect' zero-forward-speed touchdown across the furrows of a deeply ploughed field without so much as a scratch on the little Ranger (oh .. I mean JetRanger).
What I can say, following this experience, is that whatever happens immediately following an abrupt and complete loss of power is completely reactionary. If you were to say to yourself "Oh my, how odd, what is going on here" .. that would be too late (at least in a single below say a height above ground of around 1,000ft) .
I was astonished, and I mean astonished, at how quickly everything happened. One moment we were in the cruise .. then .. about 60 seconds later we were on the ground in a field in the middle of what seemed to be nowhere .. in a helicopter with its rotors having almost completed their wind-down. I remember it was extremely quiet after we landed.
Single-engine pilots are trained to continually identify prospective landing areas along their journey's way but .. even with this instinct fully aroused .. once you are faced with a 'live' engine failure it works a little differently to the 'theorised' procedure. The first response is absolutely and unequivocally that of 'sorting-out' the aircraft; regaining controlled attitudes and regulating Nr. As you are doing this you are looking at where you are going to go (not where you would like to go). Depending on your height (we didn't have much) the radius of autorotational flight can be startlingly limited.
Though my godfather taught me to fly from an early age, I had to receive formal training for my initial licence and which task fell to late great Sqn Ldr Anthony 'Antonio' 'Nobby' Clarke who Dennis 'Denissimo' Kenyon had installed as Chief Flying Instructor at his new operation at Booker in the early 80's.
I have to say that Tony taught a 'collective down' policy (as indeed did the late Colin Bates former Chief Pilot of Air Hanson and with whom I flew a base-check in the former Ferranti 206 G-AZZB). But, in both cases, they taught 'attitude control' (meaning cyclic input) as a measured response according to the 'profile' of the auorotation, ie. was it a long or short distance auto, were there turns, was it steep/shallow etc.
This emphasis on preserving (and thereafter controlling) Nr through a reduction in collective (in my mind at least) assumed that cyclic input would be commensurate with the 'automatic' changes in aircraft attitude following a loss of power and which in practice (as per the real life event described above) is what happened.
One needs also to recognise the subtle differences between simulated and actual emergencies. In simulated autorotations you know precisely where you will land. When you encounter an unexpected actual engine failure you do not (at least not to begin with). In simulated autorotations you are 'prepared' (and in most cases with hands and feet fully engaged with all controls) whereas with an actual engine failure you are not specifically prepared any may not have 'active interface' with the flying controls. As mentioned, my left hand was on my lap in the scenario described above but .. it could have been different. Colin Chapman's 206 (because of the frequent travel to European Grand Prix) was fitted with a Collins 3 axis autopilot. Mercifully .. I had not engaged it for the cyclic-mounted disable switch was only available from the right-hand seat (which I was occupying) and not from the dual cyclic where my godfather sat. Having to disable the autopilot from the panel would have been an unwanted and I would add .. dangerous distraction in our particular scenario although I am sure that my godfather would have pushed through the autopilot's breakthrough force had he been required to do so.
In summary:
* In a single engine when experiencing a real life power failure (or I suppose even a twin with a simultaneous double-engine power failure) the preservation of Nr is critical.
* This is accomplished by means of manipulation of the flight controls in which a reduction of the main rotor pitch is essential to
sustain autorotation and where adjustments to cyclic input will affect the
quality of that autorotation.
* At a height of 1,000ft or less, the radius of autorotational flight is limited and in an actual 'event' the number of suitable landing locations can be similarly limited (unless you happen to be over a level and open area).
* In a real life scenario, you will select your landing area only once you have regained control of the aircraft and are established in autotation.
* While practicing simulated engine failures overhead an airfield at a prepared height one can execute all manner of 'autorotational gymnastics' such as 180° turns and the like (and which at the time seem effortless), in an actual engine failure scenario your 'option' of available landing areas will be 'presented' to you and one of the first things you discover is that time is not on your side.
* During an autorotational descent you will manipulate the aircraft by means of high/low Nr to shorten/extend autorotational range and by means of cyclic inputs (and corresponding pedal adjustments) such as are necessary to set-up the aircraft to perform an arresting flare in front of (or overhead, depending on zero-forward speed touchdown or run on) the landing area you have identified.
* Everything is going to happen faster than you imagined.
I grew up with the knowledge that my godfather was an accomplished aviator and had heard many fascinating recollections of 'brave flight' between him and his former test flying colleagues (the likes of Peter Wilson, Sox Hosegood and Donald Farquarson to name but a few) but .. on that day in Norfolk I gained an enduring respect for his flying abilities.
He was quiet literally unfolding our route maps at the time, to the point that they obscured his forward field of view so that when the engine failed he (initially) had no awareness of what lay ahead. From this totally unprepared condition he assumed control of the aircraft and executed, as mentioned, a perfect autorotation.
But, I will say again, even for him, it was 'instinctive' and I would add .. in an actual emergency is when your training will shine through. It is actually impressive to see how the 'mind and body' can respond, instinctively and instantly, when confronted with a situation which demands dispatch from both.
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