text: at the refusal speed as the power is reduced 
  and braking action is initiated. 
  
  achieve the takeoff speed in the specified dis- 
  If it is apparent that the airplane is 
  tance. 
  not accelerating normally or that the airplane 
  or powerplant 
  functioning properly, 
  a decision must be made to refuse or continue 
  the decision to refuse takeoff is 
  takeoff. 
  made early in the takeoff roll, no problem 
  exists because the airplane has not gained 
  much speed and a large portion of runway 
  distance is unused. However, at speeds near 
  the takeoff speed, the airplane has used a large 
  portion of the takeoff distance and the distance 
  required to stop is appreciable. The problem 
  which exists is to define the highest speed 
  attained during takeoff acceleration from which 
  the airplane may be decelerated to a stop on 
  the runway length remaining, i.e., the “refusal 
  speed. ’ ’ 
  
  During takeoff, the airplane could be accel- 
  erated to any speed up to the refusal speed, 
  then decelerated to a stop on- the runway 
  remaining. Once past the refusal speed, the 
  airplane cannot be brought to a stop on the 
  runway remaining and the airplane is com- 
  mitted to an unsafe stop. 
  If takeoff is refused 
  when above the refusal speed, the only hope 
  is for assistance from the arresting gear, run- 
  way barrier, or an extensive overrun at the 
  end of the runway. This fact points to the 
  need for planning of the takeoff and the require- 
  ment to monitor the takeoff acceleration. 
  
  If the refusal speed data are not available, 
  the following equations may be used to ap- 
  proximate the refusal speed and distance: 