3 / 20
What is VD?
  • A
    The highest speed at which sudden, full elevator deflection (nose-up) can be made WITHOUT exceeding the design limit load factor.
  • B
    The maximum tested airspeed where the aircraft is free from any signs of dynamic pressure overload, flutter, and/or control reversal.
  • C
    A speed selected by the designer and used to assess the strength requirements in cruise.
  • D
    A specially recommended penetration speed for severe turbulence.

Design Dive Speed (VD) is the maximum speed which was considered when the airframe structure was constructed. During test flights, VD are reached by test pilots with the objective to demonstrate that the aircraft structural integrity is not put at stake at these speeds, and that the aircraft remains safely recoverable at all times.

The aircraft is designed to be capable of diving to this speed (in very smooth air) and be free of flutter, control reversal or buffeting. Control surfaces have a natural vibration frequency where they begin to “flutter” like a flag in a stiff breeze

Your Notes (not visible to others)

This question has appeared on the real examination, you can find the related countries below.