Originally Posted by Clandestino
Despite having only one pitot blocked, Birgenair crew has inexplicably decided to put its faith into the only datum in cockpit that was wrong. Simple crosschecking of two remaining ASIs would show that no1 ASI was at fault, if its failure during T/O wasn't hint enough.
That was my point re: human factors. Despite there being a logical path to determining where the technical fault lay, the fact that it was the Captain's instrument that was wrong and he was the handling pilot at the time created a fixation on the reading of that instrument. This was compounded by the extra warnings they were getting (specifically the audible overspeed warning) seeming to confirm what that instrument was saying. The sensory overload precluded the FO from cross-checking his ASI with the standby ASI and correctly diagnosing the fault.
It's drilled into pilots from their first flight - trust your instruments over all else. When the instruments provide unreliable information you're in a very dangerous situation and need to get out of it as quickly as possible. What the report about the ANZ A320 incident seems (quite reasonably) to be saying is that in a test flight condition you need to presume that the information you are given may not be correct and give yourself an extra margin of safety accordingly - this was not done.