On 7 Feb 2004 09:40:55 -0700, (Mark James Boyd)
wrote:

Yep. So add in a calculation for time to airspeed. And add in
a calculation for ground distance to airspeed. If one detects
that the acceleration and airspeed aren't coming up at that point,
abort the takeoff (presumably that point is calculated to be
the point of safe abort).

Add a little data about brake authority (wet runway, maximum wheel
brake temperatures depending on OAT), wind conditions, flap setting
(affects acceleration due to drag), and you get the complex scheme
that is being used today.

FYI: In the early days of jet aviation the pilots of the B-47 bomber
indeed used a stop watch. If a certain speed was not achieved after a
certain time, the takeoff was aborted.

Bye
Andreas