AMC 25.107(d) Take-off speeds

• ED Decision 2003/2/RM found in: CS-25 Amdt 27 - Large Aeroplanes (Jan 2023)

AMC 25.107(d) Take-off speeds ED Decision 2003/2/RM 1 If cases are encountered where it is not possible to obtain the actual VMU at forward centre of gravity with aeroplanes having limited elevator power (including those aeroplanes which have limited elevator power only over a portion of the take-off weight range), it will be permissible to test with a more aft centre of gravity and/or more than normal nose-up trim to obtain VMU. 1.1 When VMU is obtained in this manner, the values should be corrected to those which would have been attained at forward centre of gravity if sufficient elevator power had been available. The variation of VMU with centre of gravity may be assumed to be the same as the variation of stalling speed in free air with centre of gravity for this correction. 1.2 In such cases where VMU has been measured with a more aft centre of gravity and/or with more than normal nose-up trim, the VR selected should (in addition to complying with the requirements of [CS 25.107(e)](#_DxCrossRefBm1709820678)) be greater by an adequate margin than the lowest speed at which the nose wheel can be raised from the runway with centre of gravity at its most critical position and with the trim set to the normal take-off setting for the weight and centre of gravity. NOTE: A margin of 9,3 km/h (5 kt) between the lowest nose-wheel raising speed and VR would normally be considered to be adequate. 2 Take-offs made to demonstrate VMU should be continued until the aeroplane is out of ground effect. The aeroplane pitch attitude should not be decreased after lift-off.