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Old 27th February 2018 | 02:59
  #30 (permalink)  
megan
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Joined: Mar 2005
: Military
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From: Aus
The procedure in the Comet airliner was to lift the nose wheel off at a speed of 80 knots, and hold it off while accelerating. V1 and V2 were used in the planning eg at the maximum permissible a.u.w. of 105,000 lb the critical speed at London Airport on the E.W. runway is 95 kt I.A.S. and the unstick speed 100 kt I.A.S.

The practise of lifting the nose wheel early lead to the first two crashes of Comets, both write offs. Inability to accurately assess attitude when holding the nose wheel off lead to the possibility of the aircraft either becoming airborne in a stalled state, or not being able to accelerate to sufficient speed within the confines of the runway, all due to excessive induced drag. I maybe wrong, but I seem to recall it was these two accidents that lead to the current procedures with introduction of the Vr call.
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