Outstanding performance in an emergency (Updated)
Joined: Mar 2003
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From: uk
Public Transport flight at night in a single. Well done the pilot for a safe landing. A difficult manoeuvre especially that the throttle is not to hand like the A119/B206
The report states that there were other passengers waiting for a flight which must have taken off in the dark.
Single engine PT is not allowed at night in an AS350 in UK.
The report states that there were other passengers waiting for a flight which must have taken off in the dark.
Single engine PT is not allowed at night in an AS350 in UK.
Joined: Jun 2001
Posts: 1,650
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From: southern england
Heliport, had a great flight with them 2 years ago!
My being a "non-rotorhead", would you please explain why the tail rotor "seizure" did not lead to the helicopter "spinning"? How fast would it have been going down the runway, at touch-down?
Thanking you in advance.
My being a "non-rotorhead", would you please explain why the tail rotor "seizure" did not lead to the helicopter "spinning"? How fast would it have been going down the runway, at touch-down?
Thanking you in advance.
Last edited by newswatcher; 20th February 2004 at 20:46.
Joined: Feb 2002
Posts: 1,119
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From: N20,W99
Another excellent reason not to fly . . .
helicopters without collective twistgrip power control.
This pilot has all my undivided respect.
Hey, Bert Sousa works there, maybe he could tell us more.
This pilot has all my undivided respect.
Hey, Bert Sousa works there, maybe he could tell us more.
Last edited by BlenderPilot; 21st February 2004 at 04:05.
Thread Starter
Joined: Mar 2000
Posts: 5,197
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From: UK
newswatcher
Why did the tail rotor "seizure" not lead to the helicopter "spinning"?
Hollywood movie makers are much to blame for the idea that helicopters spin and drill a hole in the ground if the tail-rotor (or even the engine) fails, but bear in mind virtually every car that crashes in a movie bursts into a ball of flame after a massive explosion even though they rarely do in real life.
If a tail-rotor fails in the cruise, helicopters have enough stability for the pilot to fly straight while he takes the appropriate emergency action to land. The speed of the air flowing past the vertical stabiliser (the tailfin) as the helicopter flies along helps keep the helicopter flying straight.
Think of a weathercock on a church steeple – it always points in the direction the wind's coming from. Wind is a flow of air. Aircraft passing through the air at speed, even on a calm day, create an airflow past the tailfin which causes the same 'weathercock' effect.
Once the helicopter is under control, it can be flown (carefully) to the nearest suitable landing spot. The object is to land as soon as possible but there may not be a suitable/safe area in the immediate vicinity.
The tricky part is the last bit - landing with a failed tail rotor. The passengers were described as 'jittery' - I bet they were - but probably not half as jittery as the pilot because he knew all the things that could go wrong in those last few moments.
For reasons I won't go into, landing without a tail rotor is more difficult in a turbine (jet) engine helicopter (the one in the video is turbine) than in a piston engine. It's also more difficult in this particular helicopter than some because of the position of the various controls you need to use. (The same applies to some other makes/models.) I won't go into detail - let's just say it would be a lot easier if the pilot had three hands!
How fast would it have been going down the runway, at touch-down?
The pilot did a 'run on' landing which is normally about 20 knots (23 mph) at touchdown. That's not fast in car terms but, with no steering, no wheels, no brakes and a risk right up to the moment the helicopter finally stops that it could roll over, I imagine it must seem very fast!
Judging by the video, he seems to be going a lot faster than that at touchdown but you can see from the windsock the runway he's landing on isn't pointing in the same direction as the wind's coming from so he'd have to go faster to allow for that. (All aircraft, including helicopters, land into wind if possible.)
He'd want the forward speed when the helicopter touches down to be as slow as possible but he has to balance that against keeping the speed up enough to stop the nose from swinging to the side. (Remember speed and weathercock effect above.) If the nose isn't pointing in the same direction as the helicopter's moving at the moment it touches down, things can go badly wrong.
The alternative is an 'engine off' autorotation with zero groundspeed at the moment the helicopter touches down. The pilot starts a descent, closes the throttle(s) - again contrary to Hollywood image, helicopters can glide although not as far as aeroplanes - and lands. The touchdown may be a little 'firmer' than normal but experienced pilots can often do an 'engine off' as gently as a normal landing.
Which method is adopted ('run on' or 'engine off')will depend upon several factors, including the manufacturers' recommendation - their test pilots will have determined which is better for that helicopter type.
It may all seem easy but, as you've probably guessed, it's not quite so easy in practice. The Las Vegas pilot coped with the problem superbly, without anyone being killed or even injured, and he did it at night!
We're all trained to cope with a loss of tail rotor, and are regularly checked on our ability to do so, but I've never had a real failure and I'll be more than happy if it stays that way.
NB: The above is intended only as a simple summary.
Also, I'm not an instructor so apologies if my answers aren't as clear to you when you read them as they seem to me as I write them.
[Edit]
Like the questioner, I assumed the tail rotor was seized. If the pedals were jammed (see Whatsarunway's post below) and the pilot had no control of the t/r, then my response would have been different in a number of respects but, given the general nature of the questions asked, I'll leave my answers as they stand.
Why did the tail rotor "seizure" not lead to the helicopter "spinning"?
Hollywood movie makers are much to blame for the idea that helicopters spin and drill a hole in the ground if the tail-rotor (or even the engine) fails, but bear in mind virtually every car that crashes in a movie bursts into a ball of flame after a massive explosion even though they rarely do in real life.
If a tail-rotor fails in the cruise, helicopters have enough stability for the pilot to fly straight while he takes the appropriate emergency action to land. The speed of the air flowing past the vertical stabiliser (the tailfin) as the helicopter flies along helps keep the helicopter flying straight.
Think of a weathercock on a church steeple – it always points in the direction the wind's coming from. Wind is a flow of air. Aircraft passing through the air at speed, even on a calm day, create an airflow past the tailfin which causes the same 'weathercock' effect.
Once the helicopter is under control, it can be flown (carefully) to the nearest suitable landing spot. The object is to land as soon as possible but there may not be a suitable/safe area in the immediate vicinity.
The tricky part is the last bit - landing with a failed tail rotor. The passengers were described as 'jittery' - I bet they were - but probably not half as jittery as the pilot because he knew all the things that could go wrong in those last few moments.
For reasons I won't go into, landing without a tail rotor is more difficult in a turbine (jet) engine helicopter (the one in the video is turbine) than in a piston engine. It's also more difficult in this particular helicopter than some because of the position of the various controls you need to use. (The same applies to some other makes/models.) I won't go into detail - let's just say it would be a lot easier if the pilot had three hands!
How fast would it have been going down the runway, at touch-down?
The pilot did a 'run on' landing which is normally about 20 knots (23 mph) at touchdown. That's not fast in car terms but, with no steering, no wheels, no brakes and a risk right up to the moment the helicopter finally stops that it could roll over, I imagine it must seem very fast!
Judging by the video, he seems to be going a lot faster than that at touchdown but you can see from the windsock the runway he's landing on isn't pointing in the same direction as the wind's coming from so he'd have to go faster to allow for that. (All aircraft, including helicopters, land into wind if possible.)
He'd want the forward speed when the helicopter touches down to be as slow as possible but he has to balance that against keeping the speed up enough to stop the nose from swinging to the side. (Remember speed and weathercock effect above.) If the nose isn't pointing in the same direction as the helicopter's moving at the moment it touches down, things can go badly wrong.
The alternative is an 'engine off' autorotation with zero groundspeed at the moment the helicopter touches down. The pilot starts a descent, closes the throttle(s) - again contrary to Hollywood image, helicopters can glide although not as far as aeroplanes - and lands. The touchdown may be a little 'firmer' than normal but experienced pilots can often do an 'engine off' as gently as a normal landing.
Which method is adopted ('run on' or 'engine off')will depend upon several factors, including the manufacturers' recommendation - their test pilots will have determined which is better for that helicopter type.
It may all seem easy but, as you've probably guessed, it's not quite so easy in practice. The Las Vegas pilot coped with the problem superbly, without anyone being killed or even injured, and he did it at night!
We're all trained to cope with a loss of tail rotor, and are regularly checked on our ability to do so, but I've never had a real failure and I'll be more than happy if it stays that way.
NB: The above is intended only as a simple summary.
Also, I'm not an instructor so apologies if my answers aren't as clear to you when you read them as they seem to me as I write them.
[Edit]
Like the questioner, I assumed the tail rotor was seized. If the pedals were jammed (see Whatsarunway's post below) and the pilot had no control of the t/r, then my response would have been different in a number of respects but, given the general nature of the questions asked, I'll leave my answers as they stand.
Last edited by Heliport; 22nd February 2004 at 20:04.
Joined: Mar 2001
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From: Apa, apo ndi kulikonse!
Thanks for that explanation.
Now watch the video and see how amazing the flying is. I too did the flight some years back - thank God I wasn't in the back this time!
Well done anyway. Superb.
Now watch the video and see how amazing the flying is. I too did the flight some years back - thank God I wasn't in the back this time!
Well done anyway. Superb.
Joined: Jul 2000
Posts: 2,913
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From: London
whatsarunway
I appreciate we don't have the full facts yet but, in the meantime, why not assume a fellow pilot did well coping with an emergency rather speculate that he did something silly to cause it?
I'm only a PPL so I'm probably more easily impressed than high time pros, but it looks to me as if he did an excellent job salvaging the situation whatever caused it.
Tudor
I appreciate we don't have the full facts yet but, in the meantime, why not assume a fellow pilot did well coping with an emergency rather speculate that he did something silly to cause it?
I'm only a PPL so I'm probably more easily impressed than high time pros, but it looks to me as if he did an excellent job salvaging the situation whatever caused it.
Tudor
Joined: Jul 2000
Posts: 2,913
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From: London
Sorry W, I misunderstood.
=============
I've been told by an American pilot that the aft t/r control bellcrank cracked when the helicopter was a few minutes from McCarren airport. The helicopter wasn't damaged in the run-on - not even the skids - and was back in the air the next day.
Difficult job well done.
Tudor
=============
I've been told by an American pilot that the aft t/r control bellcrank cracked when the helicopter was a few minutes from McCarren airport. The helicopter wasn't damaged in the run-on - not even the skids - and was back in the air the next day.
Difficult job well done.
Tudor
Joined: Aug 2000
Posts: 3,670
Likes: 1
From: UK
Cool, calm and collected, in the face of what must be a helo drivers worst nightmare scenario.
Fantastic job - professional through and through
Heliport: your summation (might I be permitted to say) was perhaps a little on the simplistic side, regarding TR failure.
The difference between teaching and experiencing a TR failure are vast
This particular malfunction can be likened to a jammed rudder pedal in that no amount of his foot movement, altered the TR pitch. he needed to get the helo as close to (if not on the) deck at that very last torque setting which gave that 'frozen' TR pitch setting. If it 'seized' at a high TQ setting then he can either land at very low speed (one (high power)position on the drag curve) or very high speed (the mirror image (high power) other side of the drag curve). Obviously he strives for the former!
Provided he knows that the end of his helo is still intact, then the pressure backs off a little in that circumstances should remain stable. The Cof G won't change and the TR pitch won't change. Two less variables to consider!
Also the side profile of helos differs remarkably (Solid fenestron Vs Lattice tail cone and exposed TR blades) this has a marked effect on 'weathercocking'.
Always land on a very hard surface, too. It offers less friction during run on, allowing the a/c to 'skid' over the surface and not dig in and cartwheel!! If possible - foam the runway - makes it slippery and also helps with post accident fires.....
Jettison fuel if possible (bigger helos) in case you turn over and fireball!!!
Training - very few pilots concentrate on genuine quality TR mals, i would suggest, most find it too difficult to cope with, if they were honest! Either the training time is too short, or the airfield is too busy or the runway and wind is conflicting blah blah blah... Shame really.
Fantastic job - professional through and through
Heliport: your summation (might I be permitted to say) was perhaps a little on the simplistic side, regarding TR failure.
The difference between teaching and experiencing a TR failure are vast
This particular malfunction can be likened to a jammed rudder pedal in that no amount of his foot movement, altered the TR pitch. he needed to get the helo as close to (if not on the) deck at that very last torque setting which gave that 'frozen' TR pitch setting. If it 'seized' at a high TQ setting then he can either land at very low speed (one (high power)position on the drag curve) or very high speed (the mirror image (high power) other side of the drag curve). Obviously he strives for the former!
Provided he knows that the end of his helo is still intact, then the pressure backs off a little in that circumstances should remain stable. The Cof G won't change and the TR pitch won't change. Two less variables to consider!
Also the side profile of helos differs remarkably (Solid fenestron Vs Lattice tail cone and exposed TR blades) this has a marked effect on 'weathercocking'.
Always land on a very hard surface, too. It offers less friction during run on, allowing the a/c to 'skid' over the surface and not dig in and cartwheel!! If possible - foam the runway - makes it slippery and also helps with post accident fires.....
Jettison fuel if possible (bigger helos) in case you turn over and fireball!!!
Training - very few pilots concentrate on genuine quality TR mals, i would suggest, most find it too difficult to cope with, if they were honest! Either the training time is too short, or the airfield is too busy or the runway and wind is conflicting blah blah blah... Shame really.
Last edited by Thomas coupling; 22nd February 2004 at 21:38.
Joined: Jul 2000
Posts: 2,913
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From: London
Eyewitness News
Heli-USA Helicopter Back in Service
-- If you were watching Eyewitness News Thursday night, you saw our exclusive coverage of an emergency helicopter landing at McCarran Airport's Executive Terminal. People are still talking about it Friday.
It's a pretty common site to see touring helicopters -- and even news helicopters buzzing through the Las Vegas skies. And we know Thursday night's emergency landing of a Heli-USA aircraft captured a lot of attention. The tricky landing was necessary because of a problem with the tail rotor. Eyewitness News has learned that the helicopter that made numerous passes before skidding to a stop -- is already was back in service Friday.
The president of Heli-USA, Nigel Turner, says that it's back to business as usual for his company. Turner says that there is no investigation being conducted on the incident. This has been confirmed by the National Transportation Safety Board. In the meantime, the pilot is being applauded by his company, and peers, for conducting a perfect emergency landing.
Over at Silver State Helicopter school, pilots say the skid stop is something they practice routinely. "This pilot, he maneuvered everything perfectly. Everything he did was unquestionably the right maneuver," said Jerry Airola of Silver State Helicopters.
So what do the experts think of the pilot's performance Thursday night? Jerry Airola, Silver State Helicopters, said, "A-plus!" The company president says he's looking forward to getting past this incident.
It's a pretty common site to see touring helicopters -- and even news helicopters buzzing through the Las Vegas skies. And we know Thursday night's emergency landing of a Heli-USA aircraft captured a lot of attention. The tricky landing was necessary because of a problem with the tail rotor. Eyewitness News has learned that the helicopter that made numerous passes before skidding to a stop -- is already was back in service Friday.
The president of Heli-USA, Nigel Turner, says that it's back to business as usual for his company. Turner says that there is no investigation being conducted on the incident. This has been confirmed by the National Transportation Safety Board. In the meantime, the pilot is being applauded by his company, and peers, for conducting a perfect emergency landing.
Over at Silver State Helicopter school, pilots say the skid stop is something they practice routinely. "This pilot, he maneuvered everything perfectly. Everything he did was unquestionably the right maneuver," said Jerry Airola of Silver State Helicopters.
So what do the experts think of the pilot's performance Thursday night? Jerry Airola, Silver State Helicopters, said, "A-plus!" The company president says he's looking forward to getting past this incident.
Joined: Jun 2002
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From: New York City
TC
I don't disagree with what you wrote and I guess Heliport wouldn't but he was asked to explain by a "non-rotorhead" whose also a 'non-pilot' if you look at his profile.
D'ya think maybe "last torque setting which gave that 'frozen' TR pitch setting, high TQ setting, high power position on the drag curve, mirror image (high power) other side of the drag curve, CofG, Solid fenestron Vs Lattice tail cone etc etc might have been just a tiny little bit on the technical side for a non-rotorhead and non-pilot?
Maybe that's why Heliport ended his summation with " NB: The above is intended only as a simple summary."
B.
"Heliport: your summation (might I be permitted to say) was perhaps a little on the simplistic side, regarding TR failure."
D'ya think maybe "last torque setting which gave that 'frozen' TR pitch setting, high TQ setting, high power position on the drag curve, mirror image (high power) other side of the drag curve, CofG, Solid fenestron Vs Lattice tail cone etc etc might have been just a tiny little bit on the technical side for a non-rotorhead and non-pilot?
Maybe that's why Heliport ended his summation with " NB: The above is intended only as a simple summary."B.
Joined: Jul 2002
Posts: 515
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From: Denver, CO and the GOM
As Flying Lawyer said, 'twas a broken bellcrank - no tail-rotor control, T/R at flat pitch but undamaged and spinning fine.
Pilot used to be an instructor where I am now.
On board: wedding ceremony - bride & groom, pastor, witness.
Pilot used to be an instructor where I am now.
On board: wedding ceremony - bride & groom, pastor, witness.