text: where 
  
  Vi=landing  velocity corresponding  to 
  
  some original weight, W, 
  Vs = landing velocity corresponding 
  some different weight, W, 
  Thus, a given airplane in the landing con- 
  figuration at a given gross weight will have a 
  specific landing speed (MS ot CAS) which is 
  invariant with altitude, 
  temperature, wind, 
  etc., because a certain value of 4 is necessary 
  to provide lifr equal to weight at the landing 
  C,. As an example of the effect of a change in 
  gross weight, a 21 percent increase in landing 
  require a 10 percent increase in 
  weight will 
  landing speed to support the greater weight. 
  When minimum landing distances are con- 
  forces predominate 
  sidered, braking 
  during the landing toll and, for the majority 
  of airplane configurations, braking friction 
  is 
  In this case, 
  the main source of deceleration. 
  an increase in gross weight provides a greater 
  
  to 