Superpilot re “EGPWS - And associated memory items/actions. Did they switch it off? ignore it? was it not working?” (#151)
You may have overlooked the issues about ‘map-slip’ as the cause of the apparent lack of EGPWS; the degraded navigation system accuracy (FMS) would have affected the EGPWS as well.
Essentially the aircraft’s actual position would not correlate with the terrain database, thus the only warnings available were from the old style GPWS using Rad Alt.
(This line of speculation assumes that the aircraft did not have GPS nav, which based on its previous history, appears most likely).
“Asking crew to turn immediately, … ”
As above, if the map indicated erroneously that their indicated position was safe then there was a conflict of advice; the crew (human nature) chose ‘their’ solution – there ‘knew’ where they were based on ‘the map’. Unfortunately this weakness in ‘knowledge’ has been a common factor in CFIT accidents; similarly and unfortunately, a late pull up and not quite clearing a hill top.
Yes complacency, perhaps the final link in a chain of contributing factors; - not the best standard of equipment, weak systems knowledge, procedures, training, situation/weather judgement, and the ‘illusion of normality’ based on technology – ‘the magenta line on the map’.
Last edited by PEI_3721; 29th Jul 2010 at 20:16.