Nepal Plane Crash
Joined: Sep 2010
Aviation Qualifications: ATPL
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From: by the seaside
I mean, if the tail goes from a lot of negative lift, to just a little negative lift, so less negative lift from the tail, does that not mean "more" lift (hopefully what he meant....)? Obviously, you are correct in your reply about what aerodynamically happens, maybe just a language difference.
Joined: Jun 2010
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From: Kent
When you apply his equations to problems in the right context they work perfectly.
Bernoulli equations calculate the pressure drop when some part of a fluid flows faster, this is true the pressure does drop, but trying to apply this to explain why an aerofoil produces lift is flawed because the theory of why an aerofoil produces life was flawed in the first place as the principal of equal transit times has been shown to be false.
Joined: Nov 2010
Posts: 1,167
Likes: 180
From: USA
Bernoulli has not been discredited at all.
When you apply his equations to problems in the right context they work perfectly.
Bernoulli equations calculate the pressure drop when some part of a fluid flows faster, this is true the pressure does drop, but trying to apply this to explain why an aerofoil produces lift is flawed because the theory of why an aerofoil produces life was flawed in the first place as theprincipal of equal transit times has been shown to be false.
When you apply his equations to problems in the right context they work perfectly.
Bernoulli equations calculate the pressure drop when some part of a fluid flows faster, this is true the pressure does drop, but trying to apply this to explain why an aerofoil produces lift is flawed because the theory of why an aerofoil produces life was flawed in the first place as the
Joined: Nov 2010
Posts: 1,167
Likes: 180
From: USA
Joined: Nov 1999
Aviation Qualifications: ATPL
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From: UK
In the real world, the air molecules are not moving over or under a wing. They are simply sitting still, or wandering around gently, having a great day - until suddenly some metallic object whips past them: "WTF was that?", they say. The ones above got squished up together, the ones underneath not so much.
So the air molecules are not 'trying to equalise their speed over the wing' they are sitting still while the wing is doing the moving past them and pushing them up or down.
Most wind tunnels, of course, move the air molecules while keeping the wing static, and I wonder if this is where the confusion arose?
So the air molecules are not 'trying to equalise their speed over the wing' they are sitting still while the wing is doing the moving past them and pushing them up or down.
Most wind tunnels, of course, move the air molecules while keeping the wing static, and I wonder if this is where the confusion arose?
Joined: Oct 2019
Aviation Qualifications: ATPL
Posts: 171
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From: north of Harlow and south of Cambridge
What about when parked on the ramp...
In the real world, the air molecules are not moving over or under a wing. They are simply sitting still, or wandering around gently, having a great day - until suddenly some metallic object whips past them: "WTF was that?", they say. The ones above got squished up together, the ones underneath not so much.
So the air molecules are not 'trying to equalise their speed over the wing' they are sitting still while the wing is doing the moving past them and pushing them up or down.
Most wind tunnels, of course, move the air molecules while keeping the wing static, and I wonder if this is where the confusion arose?
So the air molecules are not 'trying to equalise their speed over the wing' they are sitting still while the wing is doing the moving past them and pushing them up or down.
Most wind tunnels, of course, move the air molecules while keeping the wing static, and I wonder if this is where the confusion arose?
Joined: Nov 2007
Posts: 225
Likes: 15
From: malta
In the real world, the air molecules are not moving over or under a wing. They are simply sitting still, or wandering around gently, having a great day - until suddenly some metallic object whips past them: "WTF was that?", they say. The ones above got squished up together, the ones underneath not so much.
So the air molecules are not 'trying to equalise their speed over the wing' they are sitting still while the wing is doing the moving past them and pushing them up or down.
Most wind tunnels, of course, move the air molecules while keeping the wing static, and I wonder if this is where the confusion arose?
So the air molecules are not 'trying to equalise their speed over the wing' they are sitting still while the wing is doing the moving past them and pushing them up or down.
Most wind tunnels, of course, move the air molecules while keeping the wing static, and I wonder if this is where the confusion arose?
Youbtakenthebframe of the air, in which the wing is moving. But it is totally equivalent to see it dromen the frame of the wing, in which the air is moving.
Both will come to the same result.
Joined: Jun 2002
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From: Geneva, Switzerland
Joined: Mar 2018
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From: Kathmandu
Were they immediately identifying Dead engines ? So they would be flying very close to V (mca) after noticing either of the engine failed , Would Feathering Both engines be a safe way to keep the plane gliding until they identify failed engine .
Joined: Feb 2008
Posts: 13
Likes: 0
From: Dublin, Ireland
A possibility is that they may have been too high to change runway and decided to put the engines into 100% over-ride (fine pitch) using the condition levers to create drag and maybe move them back to the Auto position when they got on the new profile but mistakenly brought them to feather.
Joined: Dec 2019
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From: OnScreen
Spurious auto-feather on TransAsia Airways ATR 72-600
And that is, indeed, what happened, according to the formal investigation conducted by the Aviation Safety Council of Taiwan (ASC). However, the instigating factor likely came as a surprise to most aviation safety specialists due to its rarity: The ASC found that the accident was prompted by a spurious activation of the propeller autofeather system.
Moreover, the council’s final report indicated that even before the accident occurred the morning of Feb. 4, 2015, there was evidence that the system could fail. It had happened twice (without further mishap) due to intermittent signal discontinuities related to aging of the system, and the engine manufacturer had issued service instructions to address the problem.
The ASC found that the airline, TransAsia Airways, had not adequately informed its flight crews of the problem and had not issued clear instructions that a takeoff must be rejected if there are any signs that the autofeather system is not working properly.
Moreover, the council’s final report indicated that even before the accident occurred the morning of Feb. 4, 2015, there was evidence that the system could fail. It had happened twice (without further mishap) due to intermittent signal discontinuities related to aging of the system, and the engine manufacturer had issued service instructions to address the problem.
The ASC found that the airline, TransAsia Airways, had not adequately informed its flight crews of the problem and had not issued clear instructions that a takeoff must be rejected if there are any signs that the autofeather system is not working properly.
Joined: Jun 2002
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From: Geneva, Switzerland
Is there any recorded aviation accident when both props would auto feather at the same time without crew input (regardless of type) ?
Now how they achieved that will be an interesting read…
Now how they achieved that will be an interesting read…
Joined: Jun 2001
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Posts: 4,087
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From: 3rd Rock, #29B
Bernoulli has not been discredited at all.
When you apply his equations to problems in the right context they work perfectly.
Bernoulli equations calculate the pressure drop when some part of a fluid flows faster, this is true the pressure does drop, but trying to apply this to explain why an aerofoil produces lift is flawed because the theory of why an aerofoil produces life was flawed in the first place as the principal of equal transit times has been shown to be false.
When you apply his equations to problems in the right context they work perfectly.
Bernoulli equations calculate the pressure drop when some part of a fluid flows faster, this is true the pressure does drop, but trying to apply this to explain why an aerofoil produces lift is flawed because the theory of why an aerofoil produces life was flawed in the first place as the principal of equal transit times has been shown to be false.
Pegase Driver
Joined: May 1997
Aviation Qualifications: ATCO
Posts: 4,454
Likes: 1,168
From: Europe
Might have been in the early pistons aircraft types when it was introduced, but all the events I remember were I always at or right after take off , Having that on base leg with reduced power ? and as you said, on both engines at the same time ? Weird.
Drain Bamaged
Joined: Mar 2000
Aviation Qualifications: ATPL
Posts: 569
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From: Earth
Disclaimer: I'm in no point saying that's what happened there but that is a possible scenario on another type of aircraft.