Originally Posted by Spitoon
There was some guidance produced as a result of discussions involving ATC and flight operations people from the CAA and aircraft operators. The guidance appears to have disappeared from the CAA website (ATSIN 27 for the ATC people) but I don't know of anywhere else it has been published.
Now incorporated into the body of MATS Part 1.
Cancelling a take-off clearance often comes up as a verbal question on ATCOs annual competency checks and a few years ago it was one of the CAA's hot topics during ATS Inspectors visits. 80KT (roughly 300m for most usual jets) is known by ATCOs as the 'critical point' beyond which, you are unlikely to attempt to stop and we have the approximate 300m position on the runway listed in our local instructions.
From the UK MATS Part 1:
Cancelling Take-off Clearance
13.1 If take-off clearance has to be cancelled before the take-off run has commenced, the pilot shall be instructed to hold position and to acknowledge the instruction.
13.2 In certain circumstances the aerodrome controller may consider that it is necessary to cancel take-off clearance after the aircraft has commenced the take-off run. In this event the pilot shall be instructed to stop immediately and to acknowledge the instruction.
13.3 The cancellation of a take-off clearance after an aircraft has commenced its take-off roll should only occur when the aircraft will be in serious and imminent danger should it continue. Controllers should be aware of the potential for an aircraft to overrun the end of the runway if the take-off is abandoned at a late stage; this is particularly so with large aircraft or those operating close to their performance limit, such as at maximum take-off mass, in high ambient temperatures or when the runway braking action may be adversely affected. Because of this risk, even if a take-off clearance is cancelled, the commander of the aircraft may consider it safer to continue the takeoff than to attempt to stop the aircraft.
13.4 As the aircraft accelerates, the risks associated with abandoning the take-off increase significantly. For modern jet aircraft, at speeds above 80kt flight deck procedures balance the seriousness of a failure with the increased risk associated with rejecting the takeoff. For example, many system warnings and cautions on the flight deck may be inhibited during the take-off roll, and between 80kt and V1 most aircraft operators define a limited number of emergency conditions in which the take-off will be rejected. Consequently, at speeds above 80kt, the take-off clearance should normally only be cancelled if there is a serious risk of collision should the aircraft continue its take-off, or if substantial debris is observed or reported on the runway in a location
likely to result in damage to the aircraft. The critical speed will be dependent on the aircraft type and configuration, environmental conditions and a range of other factors but, as a general rule, for modern jet aircraft, it will be in the region of 80kt airspeed. The typical distance at which a jet aircraft reaches 80kt is approximately 300m from the point at which the take-off roll is commenced. The unit MATS Part 2 shall contain further guidance on the likely position on the runway at which those aircraft types commonly using the aerodrome typically reach 80kt.
13.5 Controllers should also be aware of the possibility that an aircraft that abandons its take-off may suffer overheated brakes or another abnormal situation and should be prepared to declare the appropriate category of emergency or to provide other suitable assistance.