2.2 The aeroplane performance operating limitations require a length which is enough to ensure that the aeroplane
can, after starting a take-off, either be brought safely to a stop or complete the take-off safely. For the purpose of discussion it
is supposed that the runway, stopway and clearway lengths provided at the aerodrome are only just adequate for the aeroplane
requiring the longest take-off and accelerate-stop distances, taking into account its take-off mass, runway characteristics and
ambient atmospheric conditions. Under these circumstances there is, for each take-off, a speed, called the decision speed;
below this speed, the take-off must be abandoned if an engine fails, while above it the take-off must be completed. A very long
take-off run and take-off distance would be required to complete a take-off when an engine fails before the decision speed is
reached, because of the insufficient speed and the reduced power available. There would be no difficulty in stopping in the
remaining accelerate-stop distance available provided action is taken immediately. In these circumstances the correct course of
action would be to abandon the take-off.