Would ground effect and FOD ingestion be factors at high speeds close to the ground?
How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground? Also wouldn't the engines ingest FOD at that power setting that close to the ground on the approach?
ground-effect boeing-757
edited 2 days ago
Jimy
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asked 2 days ago
Rcihard Van Steenberg
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How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground? Also wouldn't the engines ingest FOD at that power setting that close to the ground on the approach?
ground-effect boeing-757
edited 2 days ago
Jimy
1,43031227
asked 2 days ago
Rcihard Van Steenberg
101
New contributor
Rcihard Van Steenberg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
1
At appears that you're thinking that an airplane traveling fast enough could never crash into the ground ...
– brhans
2 days ago
1
If an airplane could not fly close to the ground, it could never land - duh! If you want to fly in ground effect at much more than stall speed, you just need a bit of down elevator. (At least in a single engine prop plane - I can't afford a 757, but I see no reason they'd be fundamentally different.)
– jamesqf
2 days ago
add a comment |
How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground? Also wouldn't the engines ingest FOD at that power setting that close to the ground on the approach?
ground-effect boeing-757
edited 2 days ago
Jimy
1,43031227
asked 2 days ago
Rcihard Van Steenberg
101
New contributor
Rcihard Van Steenberg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground? Also wouldn't the engines ingest FOD at that power setting that close to the ground on the approach?
ground-effect boeing-757
ground-effect boeing-757
edited 2 days ago
Jimy
1,43031227
asked 2 days ago
Rcihard Van Steenberg
101
New contributor
Rcihard Van Steenberg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 2 days ago
Jimy
1,43031227
asked 2 days ago
Rcihard Van Steenberg
101
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Rcihard Van Steenberg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 2 days ago
Jimy
1,43031227
edited 2 days ago
Jimy
1,43031227
edited 2 days ago
Jimy
1,43031227
1,43031227
asked 2 days ago
Rcihard Van Steenberg
101
New contributor
Rcihard Van Steenberg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 2 days ago
Rcihard Van Steenberg
101
asked 2 days ago
Rcihard Van Steenberg
101
101
New contributor
Rcihard Van Steenberg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Rcihard Van Steenberg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Rcihard Van Steenberg is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
1
At appears that you're thinking that an airplane traveling fast enough could never crash into the ground ...
– brhans
2 days ago
1
If an airplane could not fly close to the ground, it could never land - duh! If you want to fly in ground effect at much more than stall speed, you just need a bit of down elevator. (At least in a single engine prop plane - I can't afford a 757, but I see no reason they'd be fundamentally different.)
– jamesqf
2 days ago
add a comment |
1
At appears that you're thinking that an airplane traveling fast enough could never crash into the ground ...
– brhans
2 days ago
1
If an airplane could not fly close to the ground, it could never land - duh! If you want to fly in ground effect at much more than stall speed, you just need a bit of down elevator. (At least in a single engine prop plane - I can't afford a 757, but I see no reason they'd be fundamentally different.)
– jamesqf
2 days ago
1
1
At appears that you're thinking that an airplane traveling fast enough could never crash into the ground ...
– brhans
2 days ago
At appears that you're thinking that an airplane traveling fast enough could never crash into the ground ...
– brhans
2 days ago
1
1
If an airplane could not fly close to the ground, it could never land - duh! If you want to fly in ground effect at much more than stall speed, you just need a bit of down elevator. (At least in a single engine prop plane - I can't afford a 757, but I see no reason they'd be fundamentally different.)
– jamesqf
2 days ago
If an airplane could not fly close to the ground, it could never land - duh! If you want to fly in ground effect at much more than stall speed, you just need a bit of down elevator. (At least in a single engine prop plane - I can't afford a 757, but I see no reason they'd be fundamentally different.)
– jamesqf
2 days ago
add a comment |
2 Answers
2
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votes
The amount of time a plane in a dive spends close enough to the ground to ingest foreign objects and thereby damage its engines is of order ~fractions of a second.
For a plane that is about to strike a building on the ground, the idea of FOD damage to its engines is not even relevant.
edited yesterday
TomMcW
16.9k664156
answered 2 days ago
niels nielsen
2,1091515
add a comment |
How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground?
Pitch. If an airplane's nose is low enough, it will descend and eventually collide with the ground.
In the extreme example, with the nose pointed directly down, lift is no longer holding the airplane up at all; the only force keeping the airplane's descent in check is drag. I don't know exactly how fast the plane will end up descending, but it will be pretty dang fast.
But an airplane doesn't need to be pointed straight down to have a violent collision with the ground. A shallower pitch will also work.
answered 2 days ago
Tanner Swett
1,6441726
Might want to compare SilkAir Flight 185 (even though that particular case is disputed).
– a CVn
2 days ago
add a comment |
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2 Answers
2
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votes
2 Answers
2
active
oldest
votes
active
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votes
active
oldest
votes
The amount of time a plane in a dive spends close enough to the ground to ingest foreign objects and thereby damage its engines is of order ~fractions of a second.
For a plane that is about to strike a building on the ground, the idea of FOD damage to its engines is not even relevant.
edited yesterday
TomMcW
16.9k664156
answered 2 days ago
niels nielsen
2,1091515
add a comment |
The amount of time a plane in a dive spends close enough to the ground to ingest foreign objects and thereby damage its engines is of order ~fractions of a second.
For a plane that is about to strike a building on the ground, the idea of FOD damage to its engines is not even relevant.
edited yesterday
TomMcW
16.9k664156
answered 2 days ago
niels nielsen
2,1091515
add a comment |
The amount of time a plane in a dive spends close enough to the ground to ingest foreign objects and thereby damage its engines is of order ~fractions of a second.
For a plane that is about to strike a building on the ground, the idea of FOD damage to its engines is not even relevant.
edited yesterday
TomMcW
16.9k664156
answered 2 days ago
niels nielsen
2,1091515
The amount of time a plane in a dive spends close enough to the ground to ingest foreign objects and thereby damage its engines is of order ~fractions of a second.
For a plane that is about to strike a building on the ground, the idea of FOD damage to its engines is not even relevant.
edited yesterday
TomMcW
16.9k664156
answered 2 days ago
niels nielsen
2,1091515
edited yesterday
TomMcW
16.9k664156
edited yesterday
TomMcW
16.9k664156
edited yesterday
TomMcW
16.9k664156
16.9k664156
answered 2 days ago
niels nielsen
2,1091515
answered 2 days ago
niels nielsen
2,1091515
answered 2 days ago
niels nielsen
2,1091515
2,1091515
add a comment |
add a comment |
How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground?
Pitch. If an airplane's nose is low enough, it will descend and eventually collide with the ground.
In the extreme example, with the nose pointed directly down, lift is no longer holding the airplane up at all; the only force keeping the airplane's descent in check is drag. I don't know exactly how fast the plane will end up descending, but it will be pretty dang fast.
But an airplane doesn't need to be pointed straight down to have a violent collision with the ground. A shallower pitch will also work.
answered 2 days ago
Tanner Swett
1,6441726
Might want to compare SilkAir Flight 185 (even though that particular case is disputed).
– a CVn
2 days ago
add a comment |
How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground?
Pitch. If an airplane's nose is low enough, it will descend and eventually collide with the ground.
In the extreme example, with the nose pointed directly down, lift is no longer holding the airplane up at all; the only force keeping the airplane's descent in check is drag. I don't know exactly how fast the plane will end up descending, but it will be pretty dang fast.
But an airplane doesn't need to be pointed straight down to have a violent collision with the ground. A shallower pitch will also work.
answered 2 days ago
Tanner Swett
1,6441726
Might want to compare SilkAir Flight 185 (even though that particular case is disputed).
– a CVn
2 days ago
add a comment |
How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground?
Pitch. If an airplane's nose is low enough, it will descend and eventually collide with the ground.
In the extreme example, with the nose pointed directly down, lift is no longer holding the airplane up at all; the only force keeping the airplane's descent in check is drag. I don't know exactly how fast the plane will end up descending, but it will be pretty dang fast.
But an airplane doesn't need to be pointed straight down to have a violent collision with the ground. A shallower pitch will also work.
answered 2 days ago
Tanner Swett
1,6441726
How could flight 77 into the pentagon overcome the compression lift of the ground effect at 460 KIAS that close to the ground?
Pitch. If an airplane's nose is low enough, it will descend and eventually collide with the ground.
In the extreme example, with the nose pointed directly down, lift is no longer holding the airplane up at all; the only force keeping the airplane's descent in check is drag. I don't know exactly how fast the plane will end up descending, but it will be pretty dang fast.
But an airplane doesn't need to be pointed straight down to have a violent collision with the ground. A shallower pitch will also work.
answered 2 days ago
Tanner Swett
1,6441726
answered 2 days ago
Tanner Swett
1,6441726
answered 2 days ago
Tanner Swett
1,6441726
answered 2 days ago
Tanner Swett
1,6441726
1,6441726
Might want to compare SilkAir Flight 185 (even though that particular case is disputed).
– a CVn
2 days ago
add a comment |
Might want to compare SilkAir Flight 185 (even though that particular case is disputed).
– a CVn
2 days ago
Might want to compare SilkAir Flight 185 (even though that particular case is disputed).
– a CVn
2 days ago
Might want to compare SilkAir Flight 185 (even though that particular case is disputed).
– a CVn
2 days ago
add a comment |
Rcihard Van Steenberg is a new contributor. Be nice, and check out our Code of Conduct.
Rcihard Van Steenberg is a new contributor. Be nice, and check out our Code of Conduct.
Rcihard Van Steenberg is a new contributor. Be nice, and check out our Code of Conduct.
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1
At appears that you're thinking that an airplane traveling fast enough could never crash into the ground ...
– brhans
2 days ago
1
If an airplane could not fly close to the ground, it could never land - duh! If you want to fly in ground effect at much more than stall speed, you just need a bit of down elevator. (At least in a single engine prop plane - I can't afford a 757, but I see no reason they'd be fundamentally different.)
– jamesqf
2 days ago