Witnesses Saw AA 587 Explode in Flames
Joined: Jan 2002
Posts: 15
Likes: 0
From: Downunder
Just a quick theory on the engine separation for AA587.
Scenario.
- Vertical Stabiliser fell off for reason or reasons to be determined.
- A/c became unstable vibrations felt in cockpit. (I think from an earlier thread the pilot thought wake turbulence and applied more power to compensate for what he perceived as WT.
-A/c starts yawing uncontrollably, newtons 2 law of motion about rotating objects tend to move 90 degrees out of phase with original changing force. Would be adding extra load on to engine pylons as the yawing motion turns into a pitching motion.
- A/c has kept its horizontal stabilisers so the pitching motion is constrained in the pylons and engine fittings.
- The pitching motion of the engines via newtons 2 law is turned into an additional yawing motion opposite the original motion. This could add to the original or additional yawing motion or act against any additional yawing motion. Either way the increased forces of the pylons would be pulling, twisting in all directions. The additional thrust would have added to this situation. This process would continue until the pylons could not take any more stress.
- One pylon would have to break first detaching the engine and ripping attachments and bits etc.
- With one gone the additional drag on the a/c and perhaps some loss of stability would increase the stress on the other pylon; it would then detach in a similar manner to the first. Quite probably as fuel line were separated from the engine fire may have erupted as full fuel was being pumped to the engines and the fuel lines may have ruptured prior to the final separation of the engine from the a/c
- The rest is, unfortunately, history.
Scenario.
- Vertical Stabiliser fell off for reason or reasons to be determined.
- A/c became unstable vibrations felt in cockpit. (I think from an earlier thread the pilot thought wake turbulence and applied more power to compensate for what he perceived as WT.
-A/c starts yawing uncontrollably, newtons 2 law of motion about rotating objects tend to move 90 degrees out of phase with original changing force. Would be adding extra load on to engine pylons as the yawing motion turns into a pitching motion.
- A/c has kept its horizontal stabilisers so the pitching motion is constrained in the pylons and engine fittings.
- The pitching motion of the engines via newtons 2 law is turned into an additional yawing motion opposite the original motion. This could add to the original or additional yawing motion or act against any additional yawing motion. Either way the increased forces of the pylons would be pulling, twisting in all directions. The additional thrust would have added to this situation. This process would continue until the pylons could not take any more stress.
- One pylon would have to break first detaching the engine and ripping attachments and bits etc.
- With one gone the additional drag on the a/c and perhaps some loss of stability would increase the stress on the other pylon; it would then detach in a similar manner to the first. Quite probably as fuel line were separated from the engine fire may have erupted as full fuel was being pumped to the engines and the fuel lines may have ruptured prior to the final separation of the engine from the a/c
- The rest is, unfortunately, history.
Joined: Nov 2001
Posts: 29
Likes: 0
From: Brussels
LMD,
If you look back at how things turned out then when the Concorde arrived on the market and at the number of options initially taken by US carriers for this bird, then the questions arises, and to me, the answer makes no doubt at all. But, again, this goes far beyond the scope of our topic here, and many of us could fight with each other by pulling out our respective national flag, which, at the moment, is a bit useless. So, under another title, maybe?
<img src="cool.gif" border="0"> lets take it easy <img src="cool.gif" border="0">
If you look back at how things turned out then when the Concorde arrived on the market and at the number of options initially taken by US carriers for this bird, then the questions arises, and to me, the answer makes no doubt at all. But, again, this goes far beyond the scope of our topic here, and many of us could fight with each other by pulling out our respective national flag, which, at the moment, is a bit useless. So, under another title, maybe?
<img src="cool.gif" border="0"> lets take it easy <img src="cool.gif" border="0">
Guest
Posts: n/a
The Great Leslie - Nothing was recorded on the flight recorders that indicated anywhere near 9g loads in any direction and it would take more than that to rip the engines from an airbus plane. Airbus chose to prove the engines would never come off rather than demonstrate break away capability like a Boeing.
I don't think anybody will ever know the truth including the NTSB. It's happened before and it will happen again.
<img src="frown.gif" border="0">
I don't think anybody will ever know the truth including the NTSB. It's happened before and it will happen again.
<img src="frown.gif" border="0">
Joined: Mar 2000
Posts: 8,571
Likes: 3
From: Arizona USA
Small article in the newspaper this morning mentions that "delamination" was found in the fin, further investigations follow.
AirBus....the plastic aeroplane.
Should stick to aluminum...tried and true.
And if AirBus designes its aircraft..."so the engines will never come off"...wonder if "back to the drawing board" is in order. On second thought, they would never admit to a design error or manufacturing defect.
See new thread <a href="http://www.pprune.org/ubb/NonCGI/ultimatebb.php?ubb=get_topic&f=1&t=017397" target="_blank">AA-587 Composite failure found in the tail</a>
[ 16 January 2002: Message edited by: Capt PPRuNe ]</p>
AirBus....the plastic aeroplane.
Should stick to aluminum...tried and true.
And if AirBus designes its aircraft..."so the engines will never come off"...wonder if "back to the drawing board" is in order. On second thought, they would never admit to a design error or manufacturing defect.
See new thread <a href="http://www.pprune.org/ubb/NonCGI/ultimatebb.php?ubb=get_topic&f=1&t=017397" target="_blank">AA-587 Composite failure found in the tail</a>
[ 16 January 2002: Message edited by: Capt PPRuNe ]</p>
