text: (3) Press.w~ dtitsde and tmpma~e will 
  affect the landing distance because of the 
  effect on 
  landing. 
  Thus, pressure altitude and temperature must 
  be considered to define the density altitude. 
  (4) The runway condition must be con- 
  sidered for its effect on landing distances. 
  Runway slope of ordinary values will ordi- 
  for a 
  favor selection of a runway 
  narily 
  favorable headwind at landing. The surface 
  condition of the runway will determine 
  braking effectiveness and ice or water on the 
  runway may produce a considerable increase 
  in the minimum landing distance. 
  Thus, preparation for the landing must in- 
  clude determination of the landing distance of 
  the airplane and comparison with 
  the runway 
  length available. Use of the angle of attack 
  indicator and the mirror landing system will 
  in effecting touchdown at the 
  assist the pilot 
  the proper airspeed. Of 
  desired location with 
  
  the  true airspeed for 