PPRuNe Forums - View Single Post - C-FWGH 738 slow take off BFS : AAIB
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Old 21st Jan 2018, 19:26
  #31 (permalink)  
RAT 5
 
Join Date: Jun 2000
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The call made was "Takeoff thrust set-N1 checks"

This was introduced on our B732 fleet after the Air Florida went swimming in Potomac. Same reason, blocked pitots, but via a different cause. In this AB event was in not a case of rubbish in rubbish out; i.e. wrong assumed temp entered in EFB. Cross checking the N1% for the Temp would have provided the correct corresponding answer, but still too low thrust. What was being discussed is too many modern pilots don't have a mental model with which to make gross error checks. I doubt these guys had ever taken off, even of a ferry flight, with N1% <90%, yet on this day it is reported they tried to do so. An error was made, I assume by one guy, and no bells rang for either of them. How to prevent it? Some say that the EFB should have an error alert program in it. I know some airlines where both pilots do the performance calculation independently and x-check. I'd like to see better awareness trained into pilots as well. Aviation hasn't changed that much with the advent of computers over pencil & rubber & tables. It is the same dumb humans who execute the tasks. The more complacent we become with "it's a computer so it must be correct" the more accidents of this nature we will have. After 30 years of FMC, pilots have developed a wise suspicion of VNAV profiles. They spot crazy things happening. If the FMC can be suspect and thus encourage gross error checks, why not EFB's? Too old school?
I'm amazed that some pilots are so keen eyed that they spot N1% increasing after takeoff when CLB power is selected. They often ask the reason, and can not always find the answer (it's been discussed for years on Tech Log) but at least they noticed. That's great, and we need more pilots who observe and ask questions about things that don't seem correct.
Isn't that part of our job?
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