BA 777 on fire in Las Vegas
rom the NTSB investigative update as posted here by fokkerjet
Quote:
...
• Initial examination of the left engine revealed multiple breaches of the engine case in the area around the high pressure compressor.
• Examination of the material recovered from runway found several pieces of the high pressure compressor spool (approximately 7-8 inches in length).
...
Here is a link to a detailed diagram of a GE90. The variant is the 115, so some details and proportions will differ from the accident flight. But nonprofessionals unfamiliar with basic turbofan structure designations may find it helpful.
http://lyle.smu.edu/propulsion/Pages.../turbofan2.jpe
As lomapaseo suggested above, I think the biggest outstanding question is how this failure resulted in the release of so much fuel.
Quote:
...
• Initial examination of the left engine revealed multiple breaches of the engine case in the area around the high pressure compressor.
• Examination of the material recovered from runway found several pieces of the high pressure compressor spool (approximately 7-8 inches in length).
...
Here is a link to a detailed diagram of a GE90. The variant is the 115, so some details and proportions will differ from the accident flight. But nonprofessionals unfamiliar with basic turbofan structure designations may find it helpful.
http://lyle.smu.edu/propulsion/Pages.../turbofan2.jpe
As lomapaseo suggested above, I think the biggest outstanding question is how this failure resulted in the release of so much fuel.
Nevertheless any unmitigated source of fuel inside the nacel or pylon may have to be looked for by the fire-safety group.
Without the fire this may not have been a biggie
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There is an interesting AD at https://www.google.co.uk/url?sa=t&rc...02022582,d.d2s
This refers to additional inspections on the type of engine that was installed on the aircraft in this discussion. Is it possible that even with the additional inspections that the failure mode described in this report could still have eventually occurred (i.e. uncontained engine failure at the high pressure compressor area).
This refers to additional inspections on the type of engine that was installed on the aircraft in this discussion. Is it possible that even with the additional inspections that the failure mode described in this report could still have eventually occurred (i.e. uncontained engine failure at the high pressure compressor area).
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"
• Examination of the material recovered from runway found several pieces of the high pressure compressor spool (approximately 7-8 inches in length)."
Some of the CF-6 family of engines have/had cracking problems in this area.
• Examination of the material recovered from runway found several pieces of the high pressure compressor spool (approximately 7-8 inches in length)."
Some of the CF-6 family of engines have/had cracking problems in this area.
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Crucial points and lessons learnt
I think this was an extremely serious incident that has proven that the following variables must all be present if we want to save lives:
- Well trained and experienced pilots
- Well trained and experienced cabin crew ( they are the evacuation execution experts)
- Well trained and experienced ATC personnel
- Well trained and experienced airport firemen
- A 3rd pilot helped to assess the real situation beyond cockpit based information. Each second is precious, his presence also made a significant difference in terms of speed to instigate evacuation.
Well trained and experienced professionals are not to be forgotten: this incident could have turned into a major disaster if the professionals above did not perform as expected. Professionals deserve good working conditions and decent pay, let's never forget this.
I was really impressed by the BA pilots' handling of this crisis, however I cannot ignore the excellent job done by the BA cabin crew and by the local ATC and fire services.
Just one of the above parties failing would have meant the loss of many lives. In a way this accident is a celebration of the high level professionalism needed in aviation from pilots & ATC to cabin crew & airport fire services.
- Well trained and experienced pilots
- Well trained and experienced cabin crew ( they are the evacuation execution experts)
- Well trained and experienced ATC personnel
- Well trained and experienced airport firemen
- A 3rd pilot helped to assess the real situation beyond cockpit based information. Each second is precious, his presence also made a significant difference in terms of speed to instigate evacuation.
Well trained and experienced professionals are not to be forgotten: this incident could have turned into a major disaster if the professionals above did not perform as expected. Professionals deserve good working conditions and decent pay, let's never forget this.
I was really impressed by the BA pilots' handling of this crisis, however I cannot ignore the excellent job done by the BA cabin crew and by the local ATC and fire services.
Just one of the above parties failing would have meant the loss of many lives. In a way this accident is a celebration of the high level professionalism needed in aviation from pilots & ATC to cabin crew & airport fire services.
Last edited by ILS27LEFT; 10th Sep 2015 at 21:28. Reason: corrections
A "7-8 inch" length of compressor spool is going to have lots of energy and is unlikely to be stopped by a lightweight nacelle cowling (the compressor case is designed to contain blades, but not large parts of the compressor spool).
Pure speculation on my part, but I'd bet money that one of those spool pieces sliced open the fuel line feeding the main engine fuel pump. That line is a couple inches in diameter, and the center wing tank boost pumps would be pushing fuel out the resultant opening at ~70 psi. Between the several seconds necessary for the crew to recognize the problem and command the shutdown, plus another couple seconds for the spar valve to actually close, that has the potential to be a whole lotta fuel.
While the penetration of a wing tank is certainly possible, I tend to agree with other posters than had there been a major penetration of a wing tank, things would have been even worse.
Pure speculation on my part, but I'd bet money that one of those spool pieces sliced open the fuel line feeding the main engine fuel pump. That line is a couple inches in diameter, and the center wing tank boost pumps would be pushing fuel out the resultant opening at ~70 psi. Between the several seconds necessary for the crew to recognize the problem and command the shutdown, plus another couple seconds for the spar valve to actually close, that has the potential to be a whole lotta fuel.
While the penetration of a wing tank is certainly possible, I tend to agree with other posters than had there been a major penetration of a wing tank, things would have been even worse.
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HeathrowAirport
IIO is a 275tonne MTOW model, one of only four. Whilst it was a light load, LAS is high and hot - presumably the 38*C/39*C temperature at time of incident meant a take-off quite close if not at full thrust.
IIO is a 275tonne MTOW model, one of only four. Whilst it was a light load, LAS is high and hot - presumably the 38*C/39*C temperature at time of incident meant a take-off quite close if not at full thrust.
Last edited by LASJayhawk; 10th Sep 2015 at 21:09. Reason: 3 rd times the charm
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Design certification has to ensure that an engine will contain a "Blade off Event"
You cannot design for a disc failure especially at high RPM due to the high energies involved.
You cannot design for a disc failure especially at high RPM due to the high energies involved.
Just to confirm Wiggy, the SOP for the (read and do) evac checklist is for the First Officer to make the final evacuating ATC call.
In this case it's the same voice on all VHF transmissions which makes perfect sense if the Captain was PF.
The media don't seem to have grasped that there were three highly trained pilots on the flight deck.
In this case it's the same voice on all VHF transmissions which makes perfect sense if the Captain was PF.
The media don't seem to have grasped that there were three highly trained pilots on the flight deck.
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NTNTSB detects signs of uncontained engine failure from BA 777 fire
Rather complete synopsis of findings so far from FlightGlobal.
https://www.flightglobal.com/news/ar...re-fro-416634/
https://www.flightglobal.com/news/ar...re-fro-416634/
Just to confirm Wiggy, the SOP for the (read and do) evac checklist is for the First Officer to make the final evacuating ATC call.
The media don't seem to have grasped that there were three highly trained pilots on the flight deck.
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So if you have fewer memory drills, perhaps it's because you are deviating from the manufacturer's recommendations? (Or you aren't flying Airbus/Boeing?)
I remember years ago riding in the cockpit of a B-763 with some of our Deltoid friends. They had one of those long 'before takeoff' checklists including things like 'Gyros - Erect and aligned'. At the time the Boeing 'before takeoff' checklist had only one item (I hate it when those autothrottles just won't engage
).They explained that many of the items were put in to assure commonality with the DC-8 training. Of course, the Mighty Diesel Eights were long gone by then. Drop-rise, drop-rise (or at some places - double drop-rise
).
Whip,
With respect, Emergency Evacuation is not a memory item on the B777 in BA.
Check your QRH Checklist Instructions. It is a reference checklist.
With respect, Emergency Evacuation is not a memory item on the B777 in BA.
Check your QRH Checklist Instructions. It is a reference checklist.
Years ago the evac checklist had maybe ten memory items and was sometimes hidden in some obscure tab for the amusement of the feds and sim instructors (places like 'Doors' or 'Aircraft General').
Then maybe it went down to two items like 'Parking Brake - Set', 'Tower - Notify'.
And now, as you say, a reference list with no memory items.
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I think the 13 different CL memory items is not just in reference to QRH/ECL NNC but includes the manoeuvres too. TCAS, EGPWS, Windshear etc. of course I may be mistaken. Although having just counted we have 9 check lists that require memory items (if you count severe damage and fire as 2 separate check lists). On top of that there are 6 maneuvers to remember.
Emergency evacuation is on the back of the QRH, and has been mentioned before is generally a read and do. For our outfit item 5. is Advise the cabin to evacuate (Captain) and item 6. is Advise the tower (F/O)
With regards to hand luggage; I don't think you will ever stop everyone from taking their luggage off with them. I would be interested to see evacuation trials completed where 15-20% of passengers are instructed to take hand luggage to see what effect that has on the evacuation time.
Regards
Emergency evacuation is on the back of the QRH, and has been mentioned before is generally a read and do. For our outfit item 5. is Advise the cabin to evacuate (Captain) and item 6. is Advise the tower (F/O)
With regards to hand luggage; I don't think you will ever stop everyone from taking their luggage off with them. I would be interested to see evacuation trials completed where 15-20% of passengers are instructed to take hand luggage to see what effect that has on the evacuation time.
Regards
Last edited by 320goat; 10th Sep 2015 at 22:41.
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SeenItAll, surely the report means HP Turbine, not HP compressor? In over 30 years of engine development test I've yet to see an uncontained HP compressor failure. In fact the only uncontained failures I've witnesed have from HP & IP turbine discs.
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https://www.youtube.com/watch?v=BMZp8iP6isE
On board footage including the takeoff roll and footage of the failure itself (occurs at 36 seconds)
On board footage including the takeoff roll and footage of the failure itself (occurs at 36 seconds)
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Enough about the luggage carriers.
People don't know how to behave. They don't get their own best sometimes. What everyone understands is money - so, nag the airlines to charge for cabin bags but not for hold bags. This will soon ease your trouble as the greens talk louder than any safety briefing ever will.
Medicines can be really time dependant and therefore you might consider allowing a pouch or bag big enough for various medicines. Some medicine, like those containing warfarin, is extremely time dependant and also person dependant. It can be literally life threatening to not take it at the correct time.
People don't know how to behave. They don't get their own best sometimes. What everyone understands is money - so, nag the airlines to charge for cabin bags but not for hold bags. This will soon ease your trouble as the greens talk louder than any safety briefing ever will.
Medicines can be really time dependant and therefore you might consider allowing a pouch or bag big enough for various medicines. Some medicine, like those containing warfarin, is extremely time dependant and also person dependant. It can be literally life threatening to not take it at the correct time.
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Possibly passengers perception of danger.
Having landed on water there was a much greater urgency to vacate the aircraft quickly, whereas I can only guess that a reject from around about 100kts and then stopping on the runway even with the fire and smoke seen from the left engine led to a lessor sense of urgency to vacate?
Regards
Having landed on water there was a much greater urgency to vacate the aircraft quickly, whereas I can only guess that a reject from around about 100kts and then stopping on the runway even with the fire and smoke seen from the left engine led to a lessor sense of urgency to vacate?
Regards
Medicines can be really time dependant and therefore you might consider allowing a pouch or bag big enough for various medicines. Some medicine, like those containing warfarin, is extremely time dependant and also person dependant. It can be literally life threatening to not take it at the correct time.
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=bratschewurst
I think even the most stunned folks standing on a wing in the middle of the Hudson realized they'd sink if they were holding any luggage if the plane went under - which again I'd guess most people realized was going to happen in short course.
I think even the most stunned folks standing on a wing in the middle of the Hudson realized they'd sink if they were holding any luggage if the plane went under - which again I'd guess most people realized was going to happen in short course.
Rather complete synopsis of findings so far from FlightGlobal.
There are going to be some new lessons learned in this latest event and the investigation to discover them is just beginning.
I don't view 7-8 inch long rim pieces as high energy relative to the stuff they have to get through to hole a wing or pressure vessel. Ignition at the engine metal case is a given in this type event so the persistence of the fuel must be addressed as well as the rotor failure itself.
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DevX:
No, there is historical precedent for compressor disc or spool failures. Probably much less common than turbine disc episodes. And the previously cited AD raises the suspicion further in this case.
SeenItAll, surely the report means HP Turbine, not HP compressor? In over 30 years of engine development test I've yet to see an uncontained HP compressor failure. In fact the only uncontained failures I've witnesed have from HP & IP turbine discs.