loss of control, and cause excessive structural stress to be  imposed on the aircraft.  When experiencing a loss of up-elevator control, the pilot  can retain pitch control by: When experiencing a loss of down-elevator control, the pilot  can retain pitch control by: Trim mechanisms can be useful in the event of an in-flight  primary control failure. For example, if the linkage between  the cabin and the elevator fails in flight, leaving the elevator  free to weathervane in the wind, the trim tab can be used to  raise or lower the elevator within limits. The trim tabs are not  as effective as normal linkage control in conditions such as  low airspeed, but they do have some positive effect—usually  enough to bring about a safe landing. If an elevator becomes jammed, resulting in a total loss of  elevator control movement, various combinations of power  and flap extension offer a limited amount of pitch control.  A successful landing under these conditions, however, is  problematical. Once the pilot has confirmed that the landing gear has in  fact malfunctioned and that one or more gear legs refuses  to respond to the conventional or alternate methods of gear  extension contained in the AFM/POH, there are several  methods that may be useful in attempting to force the gear  down. One method is to dive the airplane (in smooth air  only) to V$_{NE}$ speed (red line on the airspeed indicator) and  (within the limits of safety) execute a rapid pull up. In normal  category airplanes, this procedure creates a 3.8G load on the  structure, in effect making the landing gear weigh 3.8 times  normal. In some cases, this may force the landing gear into  the down and locked position. This procedure requires a  fine control touch and good feel for the airplane. Careful  consideration should be given to the fact that if the pull up  is too abrupt, it may result in an accelerated stall, possible  When selecting a landing surface, the pilot should consider  that a smooth, hard-surface runway usually causes less  damage than rough, unimproved grass strips. A hard surface  does, however, create sparks that can ignite fuel. If the airport  is so equipped, the pilot can request that the runway surface  be foamed. The pilot should consider burning off excess fuel.  This reduces landing speed and fire potential. If all efforts to extend the landing gear have failed and a gear- up landing is inevitable, the pilot should select an airport with  crash and rescue facilities. The pilot should not hesitate to  request that emergency equipment is standing by. An alternative method that has proven useful in dislodging  stuck landing gear (in some cases) is to induce rapid yawing.  After stabilizing below V$_{A}$, the pilot should alternately and  aggressively apply rudder in one direction and then the  other in rapid sequence. However, be advised that operating  at or below maneuvering speed does not provide structural  protection against multiple full control inputs in one axis or  full control inputs in more than one axis at the same time. The  resulting yawing action may cause the landing gear to fall into  place. The pilot must be aware that moving the rudder from  stop to stop is not a load limit certification requirement for  normal category airplanes. Only aircraft designed for certain  high G load flight maneuvers must have a vertical fin and  rudder capable to withstand abrupt pedal control application  to the limits in both directions.  The design maneuvering speed (V$_{A}$) is a structural design  airspeed used in determining the strength requirements for  the airplane and its control surfaces. The structural design  requirements do not cover multiple control inputs in one axis or  control inputs in more than one axis at a time at any speed, even  below V$_{A}$. Combined control inputs cause additional bending  and twisting forces. Any airspeed above the maneuvering  speed provides a positive life capability that may cause  structural damage if excessive G forces are exerted on the  aircraft. V$_{A}$ is based on the actual gross weight of the airplane  and the wing’s response to a 50 foot per second wind gust or  movement of the elevator. The combination of turbulence  and high G loading induces even greater stress on the aircraft.  Because wind gusts are not symmetrical, the total additional  stress that is added to the aircraft due to turbulence is difficult  to determine. Each element of the airframe and each flight  control component have their own design structural load limit.  Maneuvering speed is primarily determined for the wings; the  elevator may be structurally damaged below this speed. 17-10 Landing Gear Malfunction • Increasing back pressure to flare for landing • Releasing back pressure to lower the nose and  increasing back pressure to raise the nose • Pulling the control yoke aft to attain and maintain  attitude • Applying considerable nosedown trim • Releasing forward pressure to flare for landing • Increasing forward pressure to lower the nose and  relaxing forward pressure to raise the nose • Pushing the control yoke forward to attain and  maintain desired attitude • Applying considerable nose-up trim