text: The variation of the net accelerating force 
  throughout the takeoff roll is shown in figure 
  2.32. The typical propeller airplane demon- 
  strates a net accelerating force which decreases 
  with velocity and the resulting acceleration is 
  initially high but decreases throughout 
  the 
  takeoff roll. The typical jet airplane demon- 
  strates a net accelerating force which is essen- 
  tially constant throughout 
  the takeoff roll. 
  As a result, the takeoff performance of the 
  typical turbojet airpiane will compare closely 
  with the case for uniformly accelerated motion. 
  The pilot technique required to achieve peak 
  acceleration throughout 
  takeoff roll can vary 
  considerably between airplane configurations. 
  In some instances, maximum acceleration will 
  be obtained by allowing the airplane to remain 
  in the three-point attitude throughout the roll 
  until the airplane simply reaches lift-equal-to- 
  weight and flies off the ground. Other air- 
  planes may require the three-point attitude 
  until the takeoff speed is reached then rotation 
  to the takeoff angle of attack to become air- 
  borne. Still other configurations may require 
  partial or complete rotation 
  to the takeoff 
  angle of attack prior to reaching the takeoff 
  speed. In this case, the procedure may be 
  necessary to provide a smaller retarding force 
  to achieve peak acceleration. When- 
  (D+F) 
  ever any form of pitch rotation is necessary the 
  pilot must provide the proper angle of attack 
  since an excessive angle of attack will cause 
  excessive drag and hinder (or possibly pre- 
  clude) a successful takeoff. Also, irisufficient 
  rotation may provide added rolling resistance 
  or require that the airplane accelerate to some 
  to becoming airborne. 
  excessive speed prior 