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Old 30th September 2025 | 11:30
  #7 (permalink)  
Someone Somewhere
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Joined: Jan 2025
: Non-Aircrew
Posts: 640
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From: New Zealand
Debatable. Crews have come to similar grief from flap mis-selections, weight errors, takeoff starting point errors etc. N1 isn't the be-all end-all.

I would argue it's not the EPR that's the issue; it's the lack of position/acceleration monitoring.

A couple of manufacturers have started pushing Take-Off Monitoring that does a better job than just waiting for V-1 but I would argue they could go further. And given that take-off margins are being sliced increasingly thinly, probably should go further.

I would argue that you could have a system that continually calculates current position, stopping distance, climb performance etc. and can then tell you, continuously:
  • What the stopping margin would be if you aborted now (runway remaining, brake energy remaining etc.) - given the discussions around the Russian A321 that hit birds a few years back, this could even tell you if you're OK to abort after rotation/liftoff given sufficient runway remaining.
  • What the rotation/climb margins would be if you suffered an engine failure now; could you continue.
  • Expected duration of the overlap between safe abort and safe continue. If this is decreasing, something is reducing your performance below expectations. If it's negative, there will be a period where you couldn't safely handle an engine failure.
This would potentially give discretion in the period where both aborting and continuing are safe.

All that said, there's definitely a lot of human factors reasons why we have a clear go/no-go and I'm not necessarily saying it should be dropped. But it might be better served by a go/no-go point, and/or some further nuance.
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