Originally Posted by
TTex600
Auto trim fights the man trim wheel and removes any pilot applied man trim as soon as the pilot releases the wheel. When forced, the trim wheel will make jerk-y pitch movements.
In NO sense, does Airbus manual trim resemble manual trim in any other civilian jet of my experience. (various models of Lear, B737-engineering sim, DC9)
Hey Tex. Autotrim won't "fight" the manual trim wheel, but you will probably feel the electro-mechanical interlocks disengage when you hold it for the first time. As PJ2 says, when in Normal and Alternate laws, letting go of the manual trim wheel will allow autotrim to re-engage - this is per design. If you want to keep the trim held where it is you will have to hold the wheel in position - you may even get a warning that autotrim has been inhibited, but as this is what you're presumably trying to do this shouldn't be a surprise.
Originally Posted by
TTex600
As usual, my round-a-bout point is that the bus doesn't fly like "any other airplane". I have attempted to "fly it like any other airplane"' and it DONT.
I think your interpretation is too literal - but that's fair enough, given that the statement "like any other aircraft" isn't especially clear. That statement is usually made to counter the misapprehension that the FBW bus is under automatic control at all times and cannot be hand-flown. It can of course be hand-flown, and the pitch, bank and yaw commands are essentially performed in the same manner as any other aircraft through the PFC and rudder pedals.
The trim arrangement is not the same - by design - but the average layman is unlikely to know what trim does, and so that's usually put aside. The FBW Airbus pilot is not required to have trim as part of their conscious thought process, and the fact that autotrim has barely warranted discussion up until now implies that in almost all cases, that's not a problem because the system is very reliable.
In this particular design, manual trim has gone the way of wing-warping, trim tabs and cable reversion - in that other ways to implement that function have been found that either reduce pilot workload or design complexity. A pilot that does not have to trim manually is no less a pilot for not having to do so, and just because older types required manual trim to be part of the pilots' muscle memory does not mean that it should always be so.
The fundamental fact is that the trim worked the way it did because the PF's pitch commands required it to. Maybe it's worth revisiting that behaviour, maybe it isn't - but to make a blanket design change that would involve significant man hours in development, fitting and re-training on the basis of one relatively minor factor in one accident - a factor that was a consequence of crew action - would be foolish.