Sec. 25.1505 - Maximum operating limit speed.
The maximum operating limit speed (VMO/MMO
airspeed or Mach Number, whichever is critical at a particular altitude)
is a speed that may not be deliberately exceeded in any regime of flight
(climb, cruise, or descent), unless a higher speed is authorized for
flight test or pilot training operations. VMO/MMO
must be established so that it is not greater than the design cruising
speed VC and so that it is sufficiently below VD/MD
or VDF/MDF, to make it highly
improbable that the latter speeds will be inadvertently exceeded in
operations. The speed margin between VMO/MMO
and VD/MD or VDFM/DF
may not be less than that determined under §25.335(b) or found necessary
during the flight tests conducted under §25.253.
[Amdt. 25-23, 35 FR 5680, Apr. 8, 1970]