"On the accident flight the centre of gravity of the aeroplane was well rear of its aft limit and it became airborne at too low a speed to be controllable."
The question being why was it well aft of the rear limit??
As previously stated this aircraft had carried out a number of sorties without any obvious problems. The load in itself was not excessive, in as much as the pax were not unduly heavy. To put the C of G well aft on this particular flight, far enough so as to be uncontrollable, some of the load must have moved either just prior or during lift off. The question is then why? and any answer to that question can only be speculation.
How long does it ta ke to trim from full nose up to take off trim or nose down trim in a FU24. I've heard that it can take several seconds and many many winds of the trim handle
It does take a number of turns, from a dim memory maybe 10 to 12, but it can be done in a very short time, 2 or 3 seconds maybe, there is no load on the trim handle.