STABILITY AND CONTROL OF PILOTED AIRCRAFT AT HIGH ALTITUDES

The effect of altitude on airplane operating conditions is re­viewed and the influence of this altered environment on major fly­ing qualities is discussed. It is shown that aerodynamic damping suffers because of the increase in the ratio of true to indicated speed and also because of compressibility effects. Some of the difficulties expected in providing adequate static stability are also discussed and rules are formulated for assuring optimum dy­namic characteristics and freedom from dangerous coupled motions. The problems of control and maneuverability are treated briefly as are problems relating to flight out of the earth’s atmosphere.