Originally Posted by
324906
My first jet transport was the venerable B727. We went to work and MONITORED stuff. If an exceedance occurred or was likely, our monitoring led to actions to minimise damage.
[trimmed]
I cannot for the life of me work out why an engine will EVER shutdown itself, except perhaps on start when the implications are ‘who cares’, because we are not even moving. We all know that things break, failures occur. Why, for goodness sake, are we prepared to accept technical answers to problems that can be ameliorated by the unfashionable concept of active monitoring, and in doing so accept uncommanded (by flight crew) actions that impact on the operation during critical phase. I despair of what is happening to the profession and have no regrets that retirement called before all was lost. I feel that I am a dinosaur, however, some things were better in the not so distant past.
1) Because some failures happen too fast for crew to react; rotor burst due to engine overspeed being the classic example. And if you tell the crew that they must react and shut engines down in <2 seconds if they notice an anomaly, you'll have a huge number of false engine shutdowns, plus crews shutting down the wrong engine and... crashing.
2) Because a crew
didn't shut down an engine that was stuck at maximum thrust, overran the runway, and wrote off the aircraft.
3) Because fuel, cost, performance, and weight savings can be achieved by running parts closer to limits, or making equipment faster-reacting (lighter) in such a way that the situation can change too fast for humans to monitor.
The inverse can be argued: if the automation can do the job equally or more reliably, why
not automate it and let the crew focus on things that are more deserving of their attention?