Originally Posted by
hans brinker
While your understanding is mostly correct, it is not complete. Yes, mcas will add AND faster than the pilots can trim using manual electric trim, but if the pilots trim mcas will stop till 5 seconds after the manual electric trim input has stopped. As long as the pilots blip the trim every 4 seconds there should be no mcas input.
"mcas will add AND faster than the pilots can trim using manual electric trim"
To clarify. Manual Electric Trim (MET) is a bit slower than MCAS trim however Manual Electric Trim stops MCAS trim which will only re-commence 5 seconds after the Manual Electric Trim is stopped. There are numbers somewhere but the Ethiopian preliminary report FDR chart shows that MET is about 1.5 or 2 times slower than MCAS trim. Hmmm. Maybe 1/2 to 2/3 the speed is clearer, take your pick:-)
The Ethiopian preliminary report FDR chart also clearly shows the MCAS trim being prematurely interrupted by MET in at least one instance. At 05:40:27.