Good attitude instrument flying skills and good power  control are essential. The pilot should be aware of the symptoms that will be  experienced in the particular airplane as the V$_{MO}$ or M$_{MO }$is  being approached. These may include: The pilot’s response to an overspeed condition should be  to immediately slow the airplane by reducing the power  to flight idle. It will also help to smoothly and easily raise  the pitch attitude to help dissipate speed. The use of speed  brakes can also aid in slowing the airplane. If, however, the  nose-down stick forces have progressed to the extent that  they are excessive, some speed brakes will tend to further  aggravate the nose-down tendency. Under most conditions,  this additional pitch down force is easily controllable, and  since speed brakes can normally be used at any speed, they  are a very real asset. If the first two options are not successful  in slowing the airplane, a last resort option would be to  extend the landing gear, if possible. This creates enormous  drag and possibly some nose up pitch. This would be  considered an emergency maneuver. The pilot transitioning  into jet airplanes must be familiar with the manufacturers’  recommended procedures for dealing with overspeed  conditions contained in the FAA-approved Airplane Flight  Manual for the particular make and model airplane. hold the nose up. If allowed to progress unchecked, Mach  tuck may eventually occur. Although Mach tuck develops  gradually, if it is allowed to progress significantly, the center  of pressure can move so far rearward that there is no longer  enough elevator authority available to counteract it, and the  airplane could enter a steep, sometimes unrecoverable, dive. An alert pilot would have observed the high airspeed  indications, experienced the onset of buffeting, and responded  to aural warning devices long before encountering the extreme  stick forces shown. However, in the event that corrective  action is not taken and the nose is allowed to drop, increasing  airspeed even further, the situation could rapidly become  dangerous. As the Mach speed increases beyond the airplane’s  M$_{MO}$, the effects of flow separation and turbulence behind  the shock wave become more severe. Eventually, the most  powerful forces causing Mach tuck are a result of the buffeting  and lack of effective downwash on the horizontal stabilizer  because of the disturbed airflow over the wing. This is the  primary reason for the development of the T-tail configuration  on some jet airplanes, which places the horizontal stabilizer  as far as practical from the turbulence of the wings. Also,  because of the critical aspects of high-altitude/high-Mach  flight, most jet airplanes capable of operating in the Mach  speed ranges are designed with some form of trim and  autopilot Mach compensating device (stick puller) to alert the  pilot to inadvertent excursions beyond its certificated M$_{MO}$. Thus far, only the Mach buffet that results from excessive  speed has been addressed. The transitioning pilot, however,  should be aware that Mach buffet is a function of the speed  of the airflow over the wing— not necessarily the airspeed  of the airplane. Anytime that too great a lift demand is made  on the wing, whether from too fast an airspeed or from too  high an angle of attack (AOA) near the M$_{MO}$, the “high speed  buffet” will occur. However, there are also occasions when  the buffet can be experienced at much slower speeds known  as “low speed Mach buffet.” The most likely situations that could cause the low speed  buffet would be when an airplane is flown at too slow of a  speed for its weight and altitude causing a high AOA. This  very high AOA would have the same effect of increasing  airflow over the upper surface of the wing to the point that  all of the same effects of the shock waves and buffet would  occur as in the high speed buffet situation. A pilot must be aware of all the conditions that could lead  to exceeding the airplane’s maximum operating speeds.  Figure 15-10.  Example of Stick Forces versus Mach Number in a  typical jet airplane. Recovery From Overspeed Conditions Mach Buffet Boundaries 15-9 • Activation of an overspeed warning or high speed  envelope protection. • Mild buffeting as airflow separation begins to occur  after critical Mach speed. • Nose-down tendency and need for back pressure or  trim. Stick force in pounds Mach number 70 60 50 40 30 20 10 0 10 20 0 Pull Push 0.3 0.4 0.5 0.6 0.7 0.8 0.9