text: lent airspeed to provide lift equal to weight. 
  Hence, angle of attack is the primary .control of 
  If an airplane is es- 
  airspeed in mad3 fright. 
  tablished in steady, level flight at a particular 
  airspeed, any increase in angle of attack will 
  result in some reduced airspeed common to the 
  increased C,. A decrease in angle of attack 
  will 
  result in some increased airspeed com- 
  mon to the decreased CL. As a result of the 
  change in airspeed, the airplane may climb or 
  descend if there is no change in powet setting 
  but the change in airspeed was provided by 
  the change in angle of attack. The state of 
  the airplane during the change in speed will 
  be some transient condition between the 
  original and final steady state conditions. 
  
  Primary control of airspeed in steady flight 
  by angle of attack is an important principle. 
  With some configurations of airplanes, low 
  speed flight will bring about a low level of 
  longitudinal stick force stability and possi- 
  longitudi- 
  bility 
  nal stability. 
  for 
  airspeed will be light and may not furnish 
  a ready reference for easy control of the air- 
  In addition, the high angles of attack 
  plane. 
  common to low speed flight are likely to pro- 
  vide large position errors to the airspeed indi- 
  cating system. Thus, proper control of air- 
  speed will be enhanced by good “attitude” 
  flying or-when 
  poor-an angle of attack indicator. 