MSPeconomist

Rubecula

gcuk

In my view, he encountered an emergency, he stopped the plane and everyone walked away from a potential disaster. By all means the airline can learn from the report but it doesn't detract from my view that he and the crew remain heroes and I'd happily board a flight with any one of them.

Airprox

Aircraft are certified for their maximum number of passengers based on a 90 second evacuation using only half of the doors.

gcuk

Probably one of the few captains to get a foam salute at the conclusion of his final flight

Takiteasy

hedgehopper

Reading the Cockpit Voice Recorder transcript it seems to me if that was indeed the case that the impending retirement might have had quite an influence on his performance in those few minutes - "I can't believe it" or such like is uttered (presumably by the captain) more than once while they are dealing with the emergency.

The statements from the cabin crew in the report are also very interesting as an insight into passenger behaviour during an incident - the NTSB focusses on the level of pax evacuating with bags and a few were but it did not cause a problem - and the amount of pressure put on cc to start an evacuation uncommanded or allow passengers to go out the door before the slide has inflated etc. One cc reported being pushed by a pax near the door, people out their seats getting in the crew's way, a fallen pax was walked over, and a pax removing shoes was almost pushed out the door...awful!

Fortunate to not have any worse an outcome I think.

Cw novice

Out of interest when pilots practice engine fire drills in the simulator, do they practice to the point of shutting down the running engine as per the checklist?

cosmo74

Actual Daily Mail headline:

'Engine crack' caused British Airways fire at Las Vegas airport and the captain was to blame for the chaotic evacuation, say federal investigators

The article doesn't make great reading for BA, but comments are surprisingly supportive of the captain (surprising in that Daily Mail commentors generally like to condemn everyone)

shadowline

Interesting reading for sure - thanks for posting.

One question, from a layman;

How could the investigators have known when the crack initiated, considering there had been no record of it before the investigation?

KARFA

i would think so during the sim check if that's what the scenario dictates.

The Quick Reference Handbook comprises all the flows and checklists for dealing with situations. For a handful of situations some of the items for the issue are noted as memory items, i.e. you must know those items without having to grab the QRH and go the the relevant page. Part of the procedure for dealing with an engine fire are memory items and those memory items include isolating, shutting down, and activating the fire suppression system on the affected engine. On the back page of the QRH is the evacuation checklist which I don't think has any memory items so you do it from the list, Included in that is the item to shut down all engines (if not already shut down).

The 777 has electronic checklists as well which are completed and checked off on screen rather than doing them from paper but I don't know whether they include non-normal check lists - sorry I haven't had a chance to read the report yet.

Stez

The crack propagated with each stress cycle. A density measurement was taken to measure the evolution of the cracks.

Excerpt from the report:

Metallurgical examination determined that the stage 8-10 spool fracture resulted from a crack that initiated in the web aft face of the stage 8 disk. SEM examination of the stage 8 disk found that the crack initially propagated with intergranular features with local variation, which was consistent with hold-time, high alternating stress, low-cycle fatigue (also referred to as sustained-peak low-cycle fatigue). Sustained-peak low-cycle fatigue is an environmentally assisted failure mode in which a cyclic stress profile with an extended hold time, combined with an oxidizing atmosphere and elevated temperature, leads to oxidation of grain boundaries, which become brittle and eventually crack along an intergranular path.

The examination also found that the crack transitioned to transgranular, striated areas that decreased in density as the crack progressed through the web thickness, which was consistent with low-cycle fatigue. GE's striation density measurements though the transgranular region of the accident stage 8 disk determined that the low-cycle fatigue cycle count was between about 5,000 and 5,700 cycles. As previously stated, at the time of the accident, the HPC stage 8-10 spool had accumulated 11,459 cycles since new and 3,943 cycles since last inspection. The last inspection did not require the aft face of the stage 8 disk web to be inspected.

KARFA

One thing I noted in the report was the door usage during evacuation and specifically slides not being usable thereby stopping use of that door.

The 777 has four doors either side, 1L, 1R, 2L, and 2R forward of the wing, and 3L, 3R, 4L, and 4R behind the wing.

Doors 1L, 2L, 2R, and 3L were deemed not usable by the CC due to external hazards leaving four doors 1R, 3R, 4L, and 4R which could be used. Of those four, the slide didn't correctly deploy on two of them 3R and 4R leaving only 1R and 4L which were used to evacuate. I am sure in previous reports there have been issues with slide deployment on the 777 - is there an issue with the slides on that aircraft or is there normally a high failure rate for slides? It seems half of the usable doors couldn't be used due to slides not deploying properly which surely has to be concerning. The wind speed noted at the back of the report of 6 kts doesn't seem particularly high to cause problems?

Tiger_lily

Tiger_lily