AA 763 engine failure on ground run
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Well this is why we (MX) do ground runs for fault confirmation. Sometimes the only way to confirm the fault is to run the engine and risk further damage to the engine or as in this case the airframe as well. Sometimes after performing all the required inspections for engine complaints and finding no faults the run up is the only way to ensure serviceability. In nearly all the manuals today it is stated "further operation of the engine for troubleshooting may result in further damage"
On the other hand with the pressures involved in our industry to get airplanes in the air the run up could be used to shortcut the longer inspection process.
I hope that this was not the case.
Better on the ground during maint. than in the air with pax,
Happy flying
SB03
On the other hand with the pressures involved in our industry to get airplanes in the air the run up could be used to shortcut the longer inspection process.
I hope that this was not the case.
Better on the ground during maint. than in the air with pax,
Happy flying
SB03
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Originally Posted by NorthSeaTiger
Is this a pic of the actual incident occuring ?
http://www.airliners.net/open.file/1059747/M/
http://www.airliners.net/open.file/1059747/M/
I have a technical question on the visible fire.
It looks like the fire is above the ground level,?
It seems like that the engine burner flame was open to the outside and that the fuel visibly leaking from the wing in previous photos is ignited?
But does the photo above imply that the fuel leak never reached the ground before ignition?
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Knowing nothing about the lockout systems in the fuel for the CF6-80A or 767 I'd guess that until the fuel supply was shut-off there would have been a continual supply for the fire from the combustor(s).
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Originally Posted by lomapaseo
I believe that it is a photo of the subject event.
I have a technical question on the visible fire.
It looks like the fire is above the ground level,?
It seems like that the engine burner flame was open to the outside and that the fuel visibly leaking from the wing in previous photos is ignited?
But does the photo above imply that the fuel leak never reached the ground before ignition?
I have a technical question on the visible fire.
It looks like the fire is above the ground level,?
It seems like that the engine burner flame was open to the outside and that the fuel visibly leaking from the wing in previous photos is ignited?
But does the photo above imply that the fuel leak never reached the ground before ignition?
This is apparently a picture taken with the engine burning while it is still rotating. The exhaust will be blowing the fire rearwards.
Fire warnings don't illuminate for internal engine fires. The fire warning system is for fires outside of the engine core and under the cowling. Actually heat sensors so bleed line failures can illuminate fire warning lights.
The following exchange highlights how the fire warnings system doesn't cover all possibilities -
(Paraphrased) - "your right engine has a fire in the tail section."
"we don't show anything on our instruments." (engine's shutdown)
"I'm telling you it's burning."
"Still? We don't show anything in here."
"Well it's getting worse. If it was me I'd get out of there."
"Ground, xxx is evacuating."
Tailpipe fire that damaged the engine and continued to burn after the engine was shutdown.
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not only does the fire warning/detection system miss fires outside the protected area (see former post) but so does the FIRE EXTINGUSIHING system. In previous posts I've mentioned seeing someone "shoot the bottle" for a fire outside the protected area...totally wasting the charge.
:-)
:-)
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Originally Posted by JamesT73J
Knowing nothing about the lockout systems in the fuel for the CF6-80A or 767 I'd guess that until the fuel supply was shut-off there would have been a continual supply for the fire from the combustor(s).
1) Fuel limit schedules in any modern gas turbine are proportional to HPC exit pressure, and it was instantly dumped when the case was ruptured by HPT parts. Undoubtedly there was an instantaneous fireball, but I doubt the engine fire lasted more than a second or two.
2) The HP fuel pump is driven by the N2 gearbox, which came quickly to a halt.
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I understood that some 10,000 gallons of jet fuel was spilled in this 767 incident.
Wow
And while barit is right, there are reasons to think that the fuel may have stopped being pumped to the engine in question when it "blew up", one might also recall that electric fuel pumps are delivering fuel to the engine area, especially if the fuel line broke. This may have contributed to that amazing flame in the photo, but we cannot know for sure.
the fuel pump (mechanical) that is such a critical part of the engine almost certainly stopped briefly after the BOOM. But fuel under pressure to a broken line may have continued to be pumped until the fire procedures/emergency shut down checks were done and the fuel supply was cutoff at the wing valve.
regards
jon
Wow
And while barit is right, there are reasons to think that the fuel may have stopped being pumped to the engine in question when it "blew up", one might also recall that electric fuel pumps are delivering fuel to the engine area, especially if the fuel line broke. This may have contributed to that amazing flame in the photo, but we cannot know for sure.
the fuel pump (mechanical) that is such a critical part of the engine almost certainly stopped briefly after the BOOM. But fuel under pressure to a broken line may have continued to be pumped until the fire procedures/emergency shut down checks were done and the fuel supply was cutoff at the wing valve.
regards
jon
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Don't forget that engine oil burns well too, and since there were undoubtedly many broken oil lines this oil fire may have persisted long enough to help get the fuel tank spillage alight.
The wind is blowing pretty strong along the ramp too, a west wind if I interpret the sun angle correctly.
The wind is blowing pretty strong along the ramp too, a west wind if I interpret the sun angle correctly.
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One of the previous photographs showed the aftermath and there was fuel still streaming from a rupture in the fuel tanks close to the engine. Perhaps this was feeding the fire until the emergency services extinguished it?
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I'd guess that the photo is from the first second or two of the incident - note the cloud of dust that looks to be about halfway between the camera and the aircraft, (parallax makes it appear to be in front of the burning engine). I'd guess that's from one of the ejected bits hitting the ground.
Originally Posted by Beanbag
I'd guess that the photo is from the first second or two of the incident - note the cloud of dust that looks to be about halfway between the camera and the aircraft, (parallax makes it appear to be in front of the burning engine). I'd guess that's from one of the ejected bits hitting the ground.
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What about like when i saw them test the A380 blade off event where the engine contains the massive blade, can they not have that for every part of the engine.
This is the only thing that semi-worries me about flying right now
This is the only thing that semi-worries me about flying right now
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The only thing that has been demonstrated to contain a turbine disk rupture is the foot-thick reinforced concrete walls of a test cell ("test bench", in certain parts of the world.)
Even so, I'm not so sure I'd linger in the plane of rotation...
Even so, I'm not so sure I'd linger in the plane of rotation...
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as the airnz uncontained turbine failure out of sydney a few years ago showed, a 767 CAN still fly heavy on one, and the damage to the aircraft didn't cause it to blow up. with respect, i think suggesting a high bypass fan engine that has gone out, will ignite fuel like an afterburning jet engine at take-off power such as the ones on concord, is not really a fair or reasonable comparison
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Originally Posted by FridayNightPalma
Looks scarily close to the fuel dump just in the background. Funny place to conduct an engine run test.
Couldn't agree more, if it is a fuel farm. Someone said earlier in the thread, they thought they were water tanks - but I don't think anyone's confirmed that.
rts