Originally Posted by
gums
The biggie is "effectively commands attitude". In other words, it will use 0.87 Nz at a pitch attitude of 30 degrees. So without increasing power, the speed/AoA changes and the THS keeps on keeping on to maintain the 30 deg pitch attitude until the jet reaches the AoA protections - HANDS OFF!!.
Well yes, but that's exactly what it's supposed to do, and pilots converting to the FBW Airbus series are trained on that aspect of the behaviour.
This has an insidious effect, as "normal" jets would require more and more back-stick to maintain the attitude due to increasing AoA as it slows down.
I don't know if "insidious" is the right word, as the behaviour is drilled into pilot training from the start. From a piloting perspective it's essentially "point and forget", and it applies whether commanding positive pitch, negative pitch or levelling off.
It's undoubtedly an aspect that's different than what went before, but time has shown that it's simple, reliable and works just fine.
Again, I must remind all that our first FBW system was a blend of AoA and Nz. So we noticed that we had full back stick and nothing was happening with the nose once we hit the AoA limit for that gee. At max AoA, we were one Nz gee command.
Which makes sense for a fighter. Engineering 101 - use the right tool for the right job!
Hi PJ2, and regards!
It is neither practically nor philosophically merely just an "iterative example of how technology has changed."
To be certain, I was referring only to the autotrim function on the FBW Airbus system - no other aspect of it.
That said, I should have thought the reason obvious; - because the old-fashioned way worked and saves lives on occasions when technology gives up and hands a mess over to the human pilot who can competently, safely take over and live to enter the snag in the log book.
Agreed totally. However to the best of my knowledge the autotrim system in and of itself has never given up and handed a mess to the pilot.
...never lets anyone think that technology should be respected. Understood, yes!, but never respected and that means knowing how to fly and think regardless of technology.
*Now* we're into philosophy. To respect someone or something is not to say one should automatically defer to that which is being respected.
Conversely when an argument is made that technology should not be respected, following that path runs the risk of negating one of the biggest motivators for wanting to understand something, does it not? In my experience, learning and understanding a subject becomes much easier and more rewarding if respect for and interest in that subject already exists.