NAVWEPS 00-801-80  OPERATING STRENGTH LIMITATIONS  cause damage from excessive  flight loads. The  usual term given to the speed at point A is the  “maneuver speed,”  since consideration of  subsonic aerodynamics wouId predict mini-  mum usable turn radius to occur at this con-  dition.  The maneuver speed is a valuable  reference point since an airplane operating  below this point cannot produce a damaging  positive flight  load.  Any combination of  maneuver and gust cannot create damage due  to excess  airload when the airplane is below  the maneuver speed.  The maneuver speed can be computed from  the following equation:  where  VP= maneuver speed  V,= stall speed  n limit = limit load factor  Of course, the stall speed and limit load factor  must be appropriate for the airplane gross  weight.  One notable fact is that this speed,  once properly computed, remains a constant  value if no significant change takes place in  the spanwise weight distribution.  The ma-  neuver speed of the subject aircraft of figure  5.4. would be  v,= loo&3  = 274 knots  EFFECT OF HIGH  SPEED FLIGHT  Many different factors may be of structural  importance in high speed flight.  Any one or  combination of these factors may be encount-  ered if the airplane is operated beyond the  limit (or redline) airspeed.  At speeds beyond the limit speed the air-  plane may encounter a critical gust. This is  especially true of a high aspect ratio airplane  with a low limit load factor. Of course, this  is also an important consideration for an air-  plane with a high limit load factor if the gust  should be superimposed 00 a maneuver. Since  the gust Ioad factor increment varies directly  with airspeed  and gust intensity, high airspeeds  must be avoided in turbulent conditions.  When it is impossible to avoid turbulent  conditions and the airplane must be subject to  gusts, the flight condition must be properly  controlled to minimize the effect of turbulence.  If possible, the airplane airspeed and power  should be adjusted prior to entry into turbu-  lence to provide a stabilized attitude.  Ob-  viously, penetration of turbulence should not  be accomplished at an excess  airspeed because  of possible structural damage. On the other  hand, an excessively low speed should not be  chosen to penetrate turbulence for the gusts  may cause stalling of the aircraft and difficulty  of control.  To select a proper penetration  airspeed the speed should not be excessively  high  or  ‘ low-the  two extremes must be  tempered. The “maneuver”  speed is an im-  portant reference  point since it is the highest  speed that can be taken to alleviate stall due  to gust and the lowest speed at which limit  load factor can be develoPed aerodynamically.  The optimum penetration speed occurs at or  very near the maneuver speed.  Aileron rever& is a phenomenon particular  to high speed flight.  When in flight at very  high dynamic pressures, the wing torsional  deflections which occur with aileron deflection  are considerable and cause noticeable change  in aileron effectiveness. The deflection of an  aileron on a rigid wing creates  a change in lift  and produces a rolling moment. In addition  the deflection of the control surface creates a  twisting moment on the wing.  When the  actual elastic wing is subject to this condition  at high dynamic pressures, the twisting mo-  ment produces measurable twisting deforma-  tions which affect the rolling performance of  the aircraft. Figure 5.5 illustrates this process  and the effect of airspeed on aileron effective-  ness. At some high dynamic pressure, the  339 