text: The effect of pressure altitude and ambient tem- 
  perature is to define density altitude and its effect 
  on landing performance. An increase in dens- 
  increase the landing velocity 
  ity altitude will 
  but will not alter the net retarding force. 
  If 
  a given weight and configuration of airplane 
  is taken to altitude above standard sea level, 
  the airplane will still require the same 4 to 
  provide lift equal to weight at the landing C,. 
  Thus, the airplane at altitude will 
  land at the 
  same equivalent airspeed (EAS) as at sea level 
  but, because of the reduced density, the true 
  airspeed (TM) will be greater. The relation- 
  ship between true airspeed and equivalent air- 
  speed is as follows: 
  
  From this relationship, the minimum land- 
  ing distance at 5,OCO ft. (u=O.8617) would be 
  16 percent greater than the minimum landing 
  distance at sea level. The approximate increase 
  in landing distance with altitude is approxi- 
  mately 3% percent for each 1,ooO ft. of altitude. 
  Proper accounting of density altitude is neces- 
  sary to accurately predict landing distance. 
  
  The effect of proper landing velocity is impor- 
  tant when runway lengths and landing dis- 
  tances are critical. The landing speeds specified 
  in the flight handbook ate generally the mini- 
  mum safe speeds at which the airplane can be 
  landed. Any attempt to land at below the 