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Old 24th June 2025 | 11:22
  #70 (permalink)  
Someone Somewhere
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Joined: Jan 2025
: Non-Aircrew
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From: New Zealand
Then it would have been a problem. They did not attempt to go around, so it was not.

I also note that all major manufacturers say that "Thrust Reverser Selection Means Full-Stop". Attempting to go around after deploying reversers has caused some pretty nasty incidents/accidents if they fail to stow.

TCMA shouldn't have activated because the engines hadn't failed, including loss of thrust control as a 'failure'. The over-sensitivity needs to be dealt with. That doesn't mean it's completely useless.

If the engines had both 'failed', and were wobbling around 70-80% N1 as CX780 saw, consider the implications:
  • You're attempting a go-around with no thrust control and potentially insufficient thrust. How well do you expect that to go? What if engine control degrades further, and the engine either rolls back closer to idle, or accelerates further and N2 overspeed protection kicks in, shutting the engine down to prevent a rotor burst?
  • You can't deploy reverse because the engines aren't at idle. So while you're trying to pull the levers through the reverse gate, you're still eating up runway with thrust applied - thrust that wouldn't be present if the engines had been shut down when they started to run away.
A properly functioning TCMA wouldn't intervene on all engines unless all engines were already doing something unexpected and unintended - that's its whole purpose.
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