Most of the technique you (DB6) describe is totally incorrect. There was only ever one occasion when students were taught to make an approach with a deliberate out-of-trim force - in the Gnat under manual control following hydraulic failure. The tailplane incidence was set to a fixed value using the standby electric trim and the approach was flown with forward pressure on the control column until the flare purely because of the insufficient pitch authority using elevator unlock alone if the TPI was set to an in-trim value on the approach - it just wasn't possible to flare sufficiently accurately or quickly enough and using the standby trim to assist with the flare either meant you'd run out of hands trying to close the throttle, flare using the control column, assist the flare using the standby trim switches as well as tring to stream the brake chute - or if you used the '399 switches' to transfer the standby trim control to the stick top you would probably overcontrol to such an extent in the flare that you would pitch up and stall. Tricky little sod, the Gnat in manual!! But that was years ago - everything is now flown using the point-and-power technique. Touch and go landings are made without recourse to changing configuration or retrimming because most service aircraft have sufficient thrust for the drag of full flap to be immaterial during touch and go landings - and the out of trim force resulting from use of this technique is minimal. However, in aircraft such as the PA28, touch and go landings should be made with the flaps retracted for the take-off. It is NOT necessary to adjust the stabilator trim during such landings - in fact it can be positively dangerous as most students will take their eyes off the outside world to retrim with potentially catastrophic results. No service aircraft is ever retrimmed during touch and go landings - except for the Vulcan during 4-engined roller landings following double asymmetric approaches when it was necessary to lower the nosewheels onto the runway and trim the rudder to neutral before setting the thrust for take-off.
Hope this is of some help.
[This message has been edited by BEagle (edited 05 November 1999).]