text: possibility of a refused takeoff before exceed- 
  ing the refusal speed. To this end, the pilot 
  must carefully evaluate airplane and power- 
  plant performance and judge the acceleration 
  of the airplane by the use of “line speeds.” 
  The accelerated motion of the airplane during 
  takeoff roll will define certain relationships be- 
  tween velocity and distance when the acceler- 
  ation of the airplane is normal. By comparison 
  of predicted and actual speeds at various points 
  along the runway, the pilot can evaluate the 
  acceleration and assess the takeoff perfotm- 
  axe. 
  
  points along the runway will allow the pilot 
  to monitor the takeoff performance and recog- 
  nize a deficiency of acceleration. Of course, 
  a deficiency of acceleration must be recognized 
  prior to reaching some point along the runway 
  where takeoff cannot be safely achieved or 
  refused 
  
  The fundamental principles of refusal speeds 
  
  and line speeds are applicable equally well to 
  single-engine and multiengine airplanes. How- 
  ever, in the case of the multiengine airplane 
  additional consideration must be given to the 
  decision to continue or refuse takeoff when 
  engine failure occurs during the takeoff roll. 
  IF failure of one engine occurs prior to reaching 
  the-refusal speed, takeoff should be discon- 
  tinued and the airplane brought to a stop on 
  the remaining runway. 
  If failure of one engine 
  c~curs after exceeding the refusal speed, the 
  airplane is committed to continue takeoff with 
  the remaining engines operative or an unsafe 
  refused take&. 
  Sn some cases, the remaining 
  runway may not be sufficient to allow acceler- 
  ation to the takeoff speed and the airplane can 
  neither takeoff or stop on the runway rcmain- 
  ibg. To facilitate consideration of this prob- 
  lem, several specific defmitions are necessary. 