Beyond the normal flight envelope is a region of flight called “unusual attitudes”. The following discussion of unusual attitudes is intended to address this region of flight, some commonly used steps in recovery and to review some of the classic conditions that commercial jet aircraft have encountered. Beyond what is presented here, combinations of conditions must be treated using procedures similar to the following and remembering the importance of ATTITUDE FLYING.

Because of its great momentum, effective thrust, low drag and reduced stability and control at high altitudes and speeds, jet transports are always exposed to the hazards of an upset. Upsets are usually brought about through diverted pilot attention, automatic flight control failure, spatial disorientation, or improper techniques during flight through turbulence. The upset condition can also be caused by sudden turbulence or windshear (wing tip vortices or severe gusts) which could place the aircraft in buffet, and if proper pilot technique is not used, the aircraft may be placed in an upset condition.

RECOVERY FROM UNUSUAL ATTITUDES.
· Disconnect autopilot and autothrottles
· Roll wings to a level attitude
· Simultaneously maneuver aircraft pitch to a safe attitude (-5º AND +5º ANU)
· Verify safe flying conditions
· Establish a safe airspeed and altitude and engage autopilot

Following the old adage, an ounce of prevention is worth a pound of cure, the following guidelines are presented for your consideration when encountering severe or extreme turbulence:

· Do not attempt to climb over unknown weather, such as embedded thunderstorms, rather fly around them.
· Fly at an altitude that provides some latitude in buffet boundary. In some cases, this may require descent to a lower altitude.
· Fly at the recommended turbulence Mach number or airspeed which should place the aircraft in the center of the buffet boundary curve.
· Do not make large changes in thrust or trim during flight through turbulence.
· Fly attitude using the PRIMARY FLIGHT DISPLAY. Ignore the Flight Director or turn it off.
· Proper interpretation of the flight instruments is essential. Over the years, it has been demonstrated time and again that flight in turbulent conditions requires maintaining a level pitch attitude. Do not chase the Flight Director, altitude or airspeed indications as these may vary widely and are unreliable in turbulence.

There are five basic instrument or flight cues which deal with pitch attitude:
1. Attitude indicator
2. Airspeed indicator
3. Altimeter
4. Vertical speed indicator
5. Variations in load factor (“G” loads)

Of these, only the attitude indicator can truly reflect pitch attitude. The remainder of these pitch cues can be false for a variety of reasons. The altimeter, for example, senses local pressure field variations which, in turbulence, can reflect errors of as much as 1.000 feet. The airspeed indicator is affected significantly by both precipitation and gusts giving rise to sudden and large excursions. Vertical speed is subject to transient displays and is reliable only with steady-state conditions. Load factor, the “G” loads sensed by the pilot, not only give erroneous clues but very strong clues which the pilot has a strong desire to follow. Thus, it can be seen that only the attitude indicator can provide accurate pitch attitude information.

CLASSICAL AIRCRAFT UPSET DISCUSSION. There are several types of gross upsets: the full stall at altitude, a steep to very steep noseup attitude, an excessive bank angle with a high-speed dive. Suggested recovery techniques for each of these is discussed below:

1. Recovery from the full stall at high altitude: This stall recovery requires more control displacement than stalls at lower altitude and a considerable altitude loss can be expected. Down elevator should be applied gently and held until a nosedown attitude is achieved. Use as much as full-down elevator as may be required. As soon as elevator is applied, maximum thrust should also be applied to assist in accelerating the aircraft out of the stalled condition. Do not rush the recovery by applying excessive nose up control force which would put the aircraft in an accelerated or secondary stall. The climb back to cruising altitude should be made using the normal climb schedule. If the stall was a result of cruising at too high an altitude for the conditions, a lower cruise altitude should be requested.
 
2. Recovery from a very steep noseup attitude: Pitch attitudes of up to 40-50º degrees without loss of airspeed requires forward elevator control pressure, accompanied by a slow smooth increase in thrust. This control pressure should be held until approximately a 10º nosedown pitch attitude is achieved. Then the control pressure should be gently relaxed as speed increases. In the extreme noseup situation, with a pitch attitude over 50º and/or with rapidly falling airspeed, roll the aircraft to approximately 45-60º of bank and permit the nose to fall through smoothly to the horizon or slightly below the horizon. Roll wings level as the airspeed recovers. This is an effective maneuver and does not produce the same passenger discomfort associated with the negative “G” recovery.
3. Recovery from a very high speed dive with an excessive bank angle. In this condition, level the wings before attempting the dive recovery. If this is not accomplished, the aircraft could be pulled into an ever-tightening spiral with increase “G” forces. Therefore, the aircraft should be rolled level through use of the ailerons only, then gently apply aft elevator and hold until the speed stops increasing. Thrust should be reduced slowly in order to prevent a possible nose-down pitching moment. It is better to leave the throttles alone until the elevator pull starts to be effective, then, slowly reduce the thrust and consider deployment of the speedbrakes. When recovery has been effected to the point of no further speed increase, be alert for the need to hold forward stick force against the aircraft’s natural longitudinal stability which will exert itself as the aircraft seeks to return to its original trim speed.

CAUTION

The following should be considered as a last resort maneuver:
    If elevator control becomes marginal during the recovery, remember that the stabilizer is more powerful than the elevator and can be used to assist recovery. When using the stabilizer, “beep” it in short bursts and observe the results before applying additional bursts.

Douglas aircraft AOMs all contain detailed procedures for Severe Turbulence and/or Heavy Rain Ingestion which should also be consulted for guidance. Remember the importance of ATTITUDE FLYING as the safest and most efficient method of upset recovery.

The above information is presented for discussion purposes only and is not intended to replace that contained in any official publication, manual or training program.