text: It must be 
  clearly distinguished that 
  the techniques for 
  minimum stop distance may differ greatly from 
  the techniques required to minimize wear and 
  tear on the tires and brakes. For the majority 
  of airplane configurations, brakes will provide 
  the most important source of deceleration for 
  all but the most severe of icy runway condi- 
  tions. Of course, aerodynamic drag is very 
  durable and should be utilized to decelerate the 
  airplane if the runway is long enough and the 
  drag high enough. Aerodynamic drag will be 
  of importance only for the initial 20 to 30 per- 
  cent of speed reduction from the point of touch- 
  down. At speeds less than 60 to 70 percent of 
  the landing speed, aerodynamic drag is of little 
  consequence and brakes will be the principal 
  source of deceleration regardless of the runway 
  surface. For the conditions of minimum land- 
  ing distance, aerodynamic drag will be a prin- 
  cipal source of deceleration only for the initial 
  portion of landing roll for very high drag con- 
  figurations on very poor runway conditions. 
  These cases are quite limited so considerable 
  importance must be assigned to proper use of 
  the brakes to produce maximum effectiveness. 
  In order to provide the maximum possible 
  retarding force, effort must be directed to pro- 
  duce the maximum normal force on the braking 
  surfaces. (See figure 6.11.) The pilot will be 
  able to influence the normal force on the brak- 
  ing surfaces during the initial part of the land- 
  ing roll when dynamic pressure is large and 
  aerodynamic forces and moments are of conse- 
  quence. During 
  this portion of the landing 
  roll the pilot can control the airplane lift and 
  the distribution of normal force to the landing 
  gears. 