Never heard of V/S mode being endorsed by Boeing for climbs/descent/cruise in turbulence. Sounds like somebody's bright idea.
Neither have I.It is obviously better when entering strong turbulence to reduce the pitch by VS to lets say 500 a min while selecting the appropriate speed than going along for the ride with possibly quite high rate of climb.
Fair enough. But my 777 FCOM supplementary procedure 16.16 (Severe Turbulence) says as follows:
"
Climb, Cruise, and Descent Considerations After takeoff, and when established in a clean climb configuration, use of
the autoflight system is recommended for flight through turbulence.
During climb and descent, use of VNAV or flight level change may result in
excessive pitch changes as the AFDS attempts to fly speed with the
elevators.
Therefore, vertical speed mode (speed on autothrottles) is
recommended for climb and descent in severe turbulence.
During cruise, VNAV and altitude hold modes both fly speed on
autothrottles and can be used in turbulence."
