The following timings are taken from a revealing video reconstruction of the 111 accident (ABC documentary):-
At -17 mins before the crash the crew detects an unusual smell (hot?); P2 leaves seat to investigate; flight attendant states no smell in cabin, but when entering the flight deck definitely smells ‘smoke’
-14 mins smoke in the flight deck
-13 mins Pan broadcast
-11 mins crew don O2 masks
-6 mins Mayday – request immediate landing
-5.30 mins FCU problems, P2 insts fail
-5 mins FDR failure, no further communications
-0 mins aircraft hits sea
Lesson to be learnt (things to be remembered): The sense of smell quickly stabilises – readjusts to the ambient, thus the flight attendant’s observation was a valid independent opinion (CRM).
Prior to this accident many of us would have followed the same process of investigation, however once a Pan was declared the decision was (should) have been to divert. A possible future option was for an immediate landing. If the crew opt for an immediate landing, an overweight landing is a lesser issue. The aircraft structure and systems will accommodate a large amount of abuse.
Why the delay in the use of O2?
A sudden change of circumstances required a Mayday call, ‘immediate landing’. Did the crew consider ditching as a possible option at this time – forward thinking?
Who amongst us would ditch? We all talk about doing it, but what is the magic trigger that would convince a captain to put the aircraft down on the sea?
What was the magic issue that enable the captain of the Nimrod to decide to ditch; can we capture that and use it during training?