Navigate / EASA

AMC 25.335(b)(1)(ii) Design Dive Speed - High speed protection function

ED Decision 2013/010/R

In any failure condition affecting the high speed protection function, the conditions as defined in CS 25.335(b)(1)(ii) still remain applicable.

It implies that a specific value, which may be different from the VD/MD value in normal configuration, has to be associated with this failure condition for the definition of loads related to VD/MD as well as for the justification to CS 25.629. However, the strength and speed margin required will depend on the probability of this failure condition, according to the criteria of CS 25.302.

Alternatively, the operating speed VMO/MMO may be reduced to a value that maintains a speed margin between VMO/MMO and VD/MD that is consistent with showing compliance with CS 25.335(b)(1)(ii) without the benefit of the high speed protection system, provided that:

(a)     Any failure of the high speed protection system that would affect the design dive speed determination is shown to be Remote;

(b)     Failures of the system must be announced to the pilots, and:

(c)      Aeroplane flight manual instructions should be provided that reduce the maximum operating speeds, VMO/MMO.

[Amdt 25/13]