BOAC: I think I was too hasty in making that statement given 737aviators post. I suspect that the early CAP was based on the first description of V1 for the earlier airplanes and the later CAP based upon the second V1 description for later airplanes. This is from chapter 17. What do you think? (its not copied over very well)
minimum V1 -the earlier airplanes
V1 has a minimum allowable value. That minimum depends on the airplane model, as the regulatory requirements changed in this regard some years ago.
For earlier airplanes, the V1speed was never allowed to be less than the ground minimum controlspeed. The intent here was to ensure that a continued takeoff would never be attempted from a
speed less than the speed at which adequate directional control is assured with an engine inoperative.
minimum V1-the later airplanes
For later airplanes, the rule is a bit different. For these airplanes, the engine failure speed is not
allowed to be less than the ground minimum control speed
. That’s different, isn’t it? Remember
that V1
is, by definition, the speed occurring one second after engine failure. If the engine failure
must not occur at less than the ground minimum control speed, then the V1
for these later airplanes may not be less than the ground minimum control speed plus the increment of speed gained during the one second interval between
VEF and V1. That new speed, one second of acceleration
faster than
VMCG has the name V1MCG and it is the minimum allowable value of V1 on
the later airplanes.