AMC 25.149 Minimum control speeds

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

AMC 25.149 Minimum control speeds ED Decision 2003/2/RM 1 The determination of the minimum control speed, VMC, and the variation of VMC with available thrust, may be made primarily by means of ‘static’ testing, in which the speed of the aeroplane is slowly reduced, with the thrust asymmetry already established, until the speed is reached at which straight flight can no longer be maintained. A small number of ‘dynamic’ tests, in which sudden failure of the critical engine is simulated, should be made in order to check that the VMCs determined by the static method are valid. 2 When minimum control speed data are expanded for the determination of minimum control speeds (including VMC, VMCG and VMCL) for all ambient conditions, these speeds should be based on the maximum values of thrust which can reasonably be expected from a production engine in service. The minimum control speeds should not be based on specification thrust, since this thrust represents the minimum thrust as guaranteed by the manufacturer, and the resulting speeds would be unconservative for most cases.