Photo of Accident to S.55 G-AOYB
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Photo of Accident to S.55 G-AOYB
Would anyone be able to give me details of this accident to G-AOYB which I believe happened in Nigeria during the Fison Airwork Contract there?
Many Thanks
KeMac
Many Thanks
KeMac
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Nigel
and I quite thought it was to reduce tail rotor roll................OOHEERRR!
D
That's why the Mk 7 had the boom lowered a few degrees to help avoid rotor strikes...........too easy after a heavy landing.
D
Inside sources say it was a sudden onset of intense gravitation pull that neither pilot or aircraft could overcome....and upon release....the tail boom popped up into the blades causing a sudden application of Newton Laws which the Tail boom lost.
Intense Gravitational Pull
SAS, I have to begrudgingly admit that is the most creative explanation for whacking a tail off!
Kind of mysteriously technological.
In late 1962/early 1963 the Ft Rucker school for boys had both straight and droop tail H-19's that one flew. Students flew both interchangeably. Instructors were very adamant about the non-use of aft cyclic in both, but almost manic about the subject in the straight tail. The two maneuvers that caused the problem were running landings and touchdown autorotations. Trouble was that this was early in the day of wheeled helicopters and there existed an instinctual tendency for pilots to slow up by dropping collective and bringing the stick aft. That was the underlying reason for the droop tail on the later H-19's. Surprisingly, though, the lesson wasn't absorbed fully and the early experience in the USN SH-3A provided further lessons along the same line. The solution in that case was a control system mod.
Thanks,
John Dixson
Kind of mysteriously technological.
In late 1962/early 1963 the Ft Rucker school for boys had both straight and droop tail H-19's that one flew. Students flew both interchangeably. Instructors were very adamant about the non-use of aft cyclic in both, but almost manic about the subject in the straight tail. The two maneuvers that caused the problem were running landings and touchdown autorotations. Trouble was that this was early in the day of wheeled helicopters and there existed an instinctual tendency for pilots to slow up by dropping collective and bringing the stick aft. That was the underlying reason for the droop tail on the later H-19's. Surprisingly, though, the lesson wasn't absorbed fully and the early experience in the USN SH-3A provided further lessons along the same line. The solution in that case was a control system mod.
Thanks,
John Dixson
Last summer I was lucky enough to fly an S-55 for a while here in the U.S. The checkout pilot was adamant about not pulling aft cyclic. Ever. But the S-55 was designed prior to the discovery of ergonomics, and the "normal" cyclic position can be quite far forward compared to modern helicopters even though all the helicopters owned by this operator hovered slightly nose-low.
Over the years my normal technique for lifting off to a hover has always been to automatically pull a little aft cyclic as I came up on the collective and then adjust as the ship became light on the skids/wheels. I did this routinely...until...one day in the S-55. Another of our pilots had his camera out and filmed one of my liftoffs - from atop of a motorhome so his vantage point was slightly above my helicopter. What I thought was just "a little" aft cyclic had the rotor blades down so close to the (drooped) tailboom that it was actually scary. I mean, it probably wouldn't have hit, but it was CLOSE! Why did Igor design it like that?? I understand it was 1949 and all, but please! (Needless to say, I changed my liftoff technique.)
The aircraft in the #1 post in this thread looks like it's parked very nicely on a pad. I suspect that some sort of mishap occured during liftoff or setdown - maybe it got into some PIO rocking or whatever - the collective can be *very* loose if all the friction is off.
It's not me in the seat, but it's the one I was flying in the Summer of 2010 (I must say, they look goofy without the transmission and oil cooler "doghouses" installed
Over the years my normal technique for lifting off to a hover has always been to automatically pull a little aft cyclic as I came up on the collective and then adjust as the ship became light on the skids/wheels. I did this routinely...until...one day in the S-55. Another of our pilots had his camera out and filmed one of my liftoffs - from atop of a motorhome so his vantage point was slightly above my helicopter. What I thought was just "a little" aft cyclic had the rotor blades down so close to the (drooped) tailboom that it was actually scary. I mean, it probably wouldn't have hit, but it was CLOSE! Why did Igor design it like that?? I understand it was 1949 and all, but please! (Needless to say, I changed my liftoff technique.)
The aircraft in the #1 post in this thread looks like it's parked very nicely on a pad. I suspect that some sort of mishap occured during liftoff or setdown - maybe it got into some PIO rocking or whatever - the collective can be *very* loose if all the friction is off.
It's not me in the seat, but it's the one I was flying in the Summer of 2010 (I must say, they look goofy without the transmission and oil cooler "doghouses" installed
I had about 1,500 hrs on the bent tailed Whirlwind, a jet propelled version, and the perils of aft cyclic was only mentioned during landing. On lift off when the collective is applied even with progressively aft cyclic the coning angle increase will compensate for the rotary star movement. All the time I was on them, 6 years, I never knew of an accident involving the chopping of the tail boom caused by pilot error.
I would guess the above accident is a result of an overpitch on arrival at the helipad so it landed heavily on the rear of the pontoons.
I would guess the above accident is a result of an overpitch on arrival at the helipad so it landed heavily on the rear of the pontoons.
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I agree with Fareast driver.
I had lots of time on Whirlwind 7s and 9s, and a bit of training on 3s but never remember being told, or worrying about, chopping the tail off.
My closest was bending the "Hockey stick" during an engine off in a 7 into dispersal with a full SAR crew and kit in the back.
Subsequently transpired that the engineers had mis-rigged the head and the rotor rpm were too low, and when I noticed it was a bit late to do anything about it.
D
I had lots of time on Whirlwind 7s and 9s, and a bit of training on 3s but never remember being told, or worrying about, chopping the tail off.
My closest was bending the "Hockey stick" during an engine off in a 7 into dispersal with a full SAR crew and kit in the back.
Subsequently transpired that the engineers had mis-rigged the head and the rotor rpm were too low, and when I noticed it was a bit late to do anything about it.D
As ab idea as to the punishment an S55/Whirlwind can take WITHOUT chopping the boom I repeat a part of a thread about the dearly departed Chunky Lord.
Apart from the collapsed undercarriage leg the aircraft had very little damage apart from a few dents. What killed it was the winch and motor assembly on the starboard side that caused the frames and stringers it was mounted on to fracture.
The beginning of August 1967, 230 Sqn morning prayers. Dave Todd, the boss used to give a question to one of the pilots and today it was Eric Smart's turn.
'You are flying back from the Plain at 200 ft downwind and the engine stops. What do you do?
'Easy,' says Eric, 'do a full flare until about 45 knots, wrack it around into wind and do a constant attitude engine off landing.'
'You can't do that,' says the boss.
'Of course you can, chorused the crowd in the briefing room.
225 and 230 Squadrons had both gone out to Borneo from Germany and practised this procedure. Dave Todd was ex FEAF in Singapore who did not.
'Right. says Chunky (ex 225).' He rubs out the days flying programme and puts everybody in the room on a 20 minute LL EOLs training sortie with him.
I am about No3. I climb in the RHS with Chunky in the LHS. We take off and Chunky knows that I can do them so we go straight into the first one. Downwind in the middle of Odiham airfield, 200ft, 90 knots. He asks me if I am ready, I say OK and he pulls the speed select. I do it as previously descibed and on the ground he announces that he is going to do one.
Off we go, not quite 200ft (180), not quite 90 knots and he tells me to pull the lever. There is, as far as I am concerned, no problem, I had done them from lower than that. He was pattering, as QHIs do until we reached 45 knots and then he turned. Left. A Whirlwind in that position will only let you get away with it when you turn right.
I knew something was wrong because the patter dried up. The aircraft was fighting against the turn and by the time we were into wind we had about 160ft and zero airspeed. Chunky stuffed the nose down to try and get some knots so we plummeted down towards the grass. At the last moment he pulled back, which made no difference to the rate of descent or the airspeed and we three-pointed onto the ground.
It did not feel very hard but the starboard undercarriage had collapsed so I watched in fascination as the rotor blades slapped on the ground and eventually we came to rest on the starboad side.
There was then a lot of huffing and puffing from the LHS as Chunky exited throught the window. A fraction of a second he was back in because the engine was still running and he had put his face over the jet pipe. He shut down the engine and dived out again followed by me who had tidied up the switches and levers.
'You are flying back from the Plain at 200 ft downwind and the engine stops. What do you do?
'Easy,' says Eric, 'do a full flare until about 45 knots, wrack it around into wind and do a constant attitude engine off landing.'
'You can't do that,' says the boss.
'Of course you can, chorused the crowd in the briefing room.
225 and 230 Squadrons had both gone out to Borneo from Germany and practised this procedure. Dave Todd was ex FEAF in Singapore who did not.
'Right. says Chunky (ex 225).' He rubs out the days flying programme and puts everybody in the room on a 20 minute LL EOLs training sortie with him.
I am about No3. I climb in the RHS with Chunky in the LHS. We take off and Chunky knows that I can do them so we go straight into the first one. Downwind in the middle of Odiham airfield, 200ft, 90 knots. He asks me if I am ready, I say OK and he pulls the speed select. I do it as previously descibed and on the ground he announces that he is going to do one.
Off we go, not quite 200ft (180), not quite 90 knots and he tells me to pull the lever. There is, as far as I am concerned, no problem, I had done them from lower than that. He was pattering, as QHIs do until we reached 45 knots and then he turned. Left. A Whirlwind in that position will only let you get away with it when you turn right.
I knew something was wrong because the patter dried up. The aircraft was fighting against the turn and by the time we were into wind we had about 160ft and zero airspeed. Chunky stuffed the nose down to try and get some knots so we plummeted down towards the grass. At the last moment he pulled back, which made no difference to the rate of descent or the airspeed and we three-pointed onto the ground.
It did not feel very hard but the starboard undercarriage had collapsed so I watched in fascination as the rotor blades slapped on the ground and eventually we came to rest on the starboad side.
There was then a lot of huffing and puffing from the LHS as Chunky exited throught the window. A fraction of a second he was back in because the engine was still running and he had put his face over the jet pipe. He shut down the engine and dived out again followed by me who had tidied up the switches and levers.
