Accelerometer (Acc) Trimming - Also called auto-LEVEL trimming - FIRST do after the GYRO & ACC calibrations and normal ACRO trimming (see above) using the Tx trims. LAND. Switch over to LEVEL mode (Gear Switch). Take off and mentally note the way the copter wants to drift - DO NOT TRIM THE TX - Land - The final ACC trimming procedure (below) is this -DISARM (see above - the Green LED will go OFF) Move the THRO to the 'Learn Position - full up) - in this example the copter was moving back and right - so ; using stick-banging - move the cyclic (right stick) up once (led blinks) - then left once (led blinks) - these alterations are saved to the CPU memory. ARM again - hover and repeat the process until the copter hovers 'level'.