Spinning an airliner
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Joined: Jan 2006
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From: Kununurra
Spinning an airliner
This is from the New Scientist. Crazy plan.
What do you think the centrifugal force required to keep the body spinning horizontally (with only one wing attached) would be?
How would the system arrest the forward motion of the plane before putting it in a falt spin? I think some of Thailand's local produce may have benn involved in inspiring the idea.
Spinning touchdown
An inventor from Bangkok is patenting an outlandish emergency landing system for aeroplanes.
Normally, when a crash landing is inevitable and no runway is in sight, a pilot would make a controlled belly flop to prevent the plane from ploughing into any buildings nearby.
But Polchai Phanumphai's idea is for aircraft to spin their way down instead. As a suitably fitted-out plane prepares to crash down, an altimeter would trigger explosive charges to make one wing break away from the fuselage and kick the one-winged plane into a horizontal spin.
Phanumphai says the spinning motion would produce lift in the same way as a helicopter's blades, while the centrifugal force should keep the body level. So, the inventor says, the falling plane ought to hit the ground relatively slowly.
The result, in theory at least, is a "reduced loss of life". But the inventor gives no clue whether the rapid spin might do more harm to the passengers than the crash landing itself. Any volunteers for a test flight?
Read full spinning aircraft patent.
What do you think the centrifugal force required to keep the body spinning horizontally (with only one wing attached) would be?
How would the system arrest the forward motion of the plane before putting it in a falt spin? I think some of Thailand's local produce may have benn involved in inspiring the idea.
Spinning touchdown
An inventor from Bangkok is patenting an outlandish emergency landing system for aeroplanes.Normally, when a crash landing is inevitable and no runway is in sight, a pilot would make a controlled belly flop to prevent the plane from ploughing into any buildings nearby.
But Polchai Phanumphai's idea is for aircraft to spin their way down instead. As a suitably fitted-out plane prepares to crash down, an altimeter would trigger explosive charges to make one wing break away from the fuselage and kick the one-winged plane into a horizontal spin.
Phanumphai says the spinning motion would produce lift in the same way as a helicopter's blades, while the centrifugal force should keep the body level. So, the inventor says, the falling plane ought to hit the ground relatively slowly.
The result, in theory at least, is a "reduced loss of life". But the inventor gives no clue whether the rapid spin might do more harm to the passengers than the crash landing itself. Any volunteers for a test flight?
Read full spinning aircraft patent.
Joined: Apr 2006
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From: LGW
Surely it would be better to just hand out parachutes as the passengers board 'just in case.' They could have the airline logo on too for a bit of free advertising as they all float down...?
And on that theme what about a HUGE parachute for the aircraft itself like the Cirrus SR22 has?
And on that theme what about a HUGE parachute for the aircraft itself like the Cirrus SR22 has?
Joined: Jun 2001
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From: Boldly going where no split infinitive has gone before..
It falls down on the same flawed assumption (though I think it falls somewhat further!!!), that crashes are foreseen, caused by aircraft faults, and therefore some form of recovery system will save them, that has led to proposals for parachute systems for airliners.
Whilst ballistic parachutes have been successful for ultralights (with a high incidence of in-flight break-up) and less so on light aircraft such as the cirrus (I believe the "Saves" on that aircraft have been a VFR into IMC incident and an in-flight pilot incapacitation) there is simply not anything like the incidence of events where this type of system would help.
The overwhelming majority of airline accidents are caused by human factors, and the first the crew know about it is when they wake up on a cloud to the sound of harp music.
Whilst ballistic parachutes have been successful for ultralights (with a high incidence of in-flight break-up) and less so on light aircraft such as the cirrus (I believe the "Saves" on that aircraft have been a VFR into IMC incident and an in-flight pilot incapacitation) there is simply not anything like the incidence of events where this type of system would help.
The overwhelming majority of airline accidents are caused by human factors, and the first the crew know about it is when they wake up on a cloud to the sound of harp music.
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From: UK
Joined: Jan 2004
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From: Here and there
Hmmm. Spinning, although accompanied by a low air speed on the ASI, is also accompanied by a very high rate of descent. People who spin into the ground generally die. I don't see this sickle seed idea providing a low enough rate of descent to be workable.
Joined: Sep 2002
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From: La Belle Province
sheer madness, of course
to achieve the equivalent lift that a convential forced-landing scenario would generate (i.e. Vref glide) with only one wing, requires an effective speed of the single wing of about 1.41Vref. That has to be averaged across the single wing, consistent with some kind of area-averaging. Let's assume that the 1.4Vref speed must be achieved at half-span. If we assume a Vref of the order of 140kts, that means that the half-span speed is 200kts, say 300fps. Assuming a 300ft span, that makes the radius of rotation about 75ft. To get 300fps at 75ft radius requires 4 rad/sec, or about 250 deg/sec. That's a huge rate to try to create.
How the lift on the single wing isn't going to cause the aircraft to roll/tumble?
How anyone is going to aim this projectile at an impact site?
crazy. proves any idiot can get a patent...
to achieve the equivalent lift that a convential forced-landing scenario would generate (i.e. Vref glide) with only one wing, requires an effective speed of the single wing of about 1.41Vref. That has to be averaged across the single wing, consistent with some kind of area-averaging. Let's assume that the 1.4Vref speed must be achieved at half-span. If we assume a Vref of the order of 140kts, that means that the half-span speed is 200kts, say 300fps. Assuming a 300ft span, that makes the radius of rotation about 75ft. To get 300fps at 75ft radius requires 4 rad/sec, or about 250 deg/sec. That's a huge rate to try to create.
How the lift on the single wing isn't going to cause the aircraft to roll/tumble?
How anyone is going to aim this projectile at an impact site?
crazy. proves any idiot can get a patent...
Psychophysiological entity
Joined: Jun 2001
Aviation Qualifications: ATPL
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From: Walton on the Naze Essex.
I'll just rely on my modified uniform raincoat.
Wooooosh, out the door...er, or the big crack in the side made by explosives in the wing root, then up, well, perhaps down down and away on the 18 sq ft of bat-cape.
That pans out at 11 lbs per sq ft.......not so bad. Now, look for a soft place to land.
Wooooosh, out the door...er, or the big crack in the side made by explosives in the wing root, then up, well, perhaps down down and away on the 18 sq ft of bat-cape.
That pans out at 11 lbs per sq ft.......not so bad. Now, look for a soft place to land.
bat fastard
Joined: Apr 2003
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From: Back home in Alba
Would the rest of the a/c structure be able to withstand the stress of a spin, especially at such a high rate?
A giant parachute is a great idea in theory but do you know what size it would have to be to bring down a 747 safely? I think I remember it being calculated at something like the size of seven football fields. Now where the hell do you store all that material in the aircraft? Not to mention the massive weight penalty.
A giant parachute is a great idea in theory but do you know what size it would have to be to bring down a 747 safely? I think I remember it being calculated at something like the size of seven football fields. Now where the hell do you store all that material in the aircraft? Not to mention the massive weight penalty.
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From: LGW
On a (slightly) more serious note does anyone know of any developments for airbags to be fitted to aircraft? Feasible or not? I guess not for large aircraft but maybe Dash and smaller maybe?
Certainly I'm sure they may be effective in a light aircraft should you ever need to use them.
Certainly I'm sure they may be effective in a light aircraft should you ever need to use them.
