Originally Posted by
Alpine Flyer
I remember reading about an "acceleration monitor" that would show a green band of "OK accel" around the airspeed "needle" that would increase according to distance travelled or whatever.
Actually this philosophy was used in the old Caravelle. Depending on your weight, temperature, elevation... with the performance charts you got a maximum amount of time to reach a given speed. If at that time you was above that speed, then ok. But if below... you had to reject the take off.
From my point of view this procedure was safer than V1. Because if you reject a T/O below V1 but acceleration during the T/O roll was poor you can be very close to the end of the RWY despite of being below V1 and therefore have a RWY overrun.