An unusual attitude is any airplane attitude not normally required for instrument flight. Unusual attitudes may result from a number of conditions, such as turbulence, disorientation, instrument failure, confusion, preoccupation with cockpit duties, carelessness in cross-checking, errors in instrument interpretation, or lack of proficiency in aircraft control. Since unusual attitudes are not intentional maneuvers during instrument flight, except in training, they are often unexpected, and the reaction of an inexperienced or inadequately trained pilot to an unexpected abnormal flight attitude is usually instinctive rather than intelligent and deliberate. This individual reacts with abrupt muscular effort, which is purposeless and even hazardous in turbulent conditions, at excessive speeds, or at low altitudes. However, with practice, the techniques for rapid and safe recovery from unusual attitudes can be learned.
When an unusual attitude is noted on your cross-check, the immediate problem is not how the airplane got there, but what it is doing and how to get it back to straight-and-level flight as quickly as possible.
Recognizing Unusual Attitudes. As a general rule, any time you note an instrument rate of movement or indication other than those you associate with the basic instrument flight maneuvers already learned, assume an unusual attitude and increase the speed of cross-check to confirm the attitude, instrument error, or instrument malfunction.
Nose-high attitudes (Fig. 5-41) are shown by the rate and direction of movement of the altimeter needle, vertical-speed needle, and airspeed needle, as well as the immediately recognizable indication of the attitude indicator (except in extreme attitudes). Nose-low attitudes (Fig. 5-42) are shown by the same instruments, but in the opposite direction.
Recovery From Unusual Attitudes. In moderate unusual attitudes, the pilot can normally reorient himself by establishing a level flight indication on the attitude indicator. However, the pilot should not depend on this instrument for these reasons: If the attitude indicator is the spillable type, its upset limits may have been exceeded; it may have become inoperative due to mechanical malfunction; even if it is the non-spillable type instrument and is operating properly, its indications are very difficult to interpret in extreme attitudes. As soon as the unusual attitude is detected, the recovery should be initiated primarily by reference to the airspeed indicator, altimeter, vertical-speed indicator, and turn coordinator.
Nose-High Attitudes. If the airspeed is decreasing or below the desired airspeed, increase power (as necessary in proportion to the observed deceleration), apply forward elevator pressure to lower the nose and prevent a stall, and correct the bank by applying coordinated aileron and rudder pressure to level the miniature aircraft and center the ball of the turn coordinator. The corrective control applications are made almost simultaneously but in the sequence given above. A level pitch attitude is indicated by the reversal and stabilization of the airspeed indicator and altimeter needles. Straight coordinated flight is indicated by the level miniature aircraft and centered ball of the turn coordinator.
Nose-Low Attitudes. If the airspeed is increasing, or is above the desired airspeed, reduce power to prevent excessive airspeed and loss of altitude. Correct the bank attitude with coordinated aileron and rudder pressure to straight flight by referring to the turn coordinator. Raise the nose to level flight attitude by smooth back elevator pressure. All components of control should be changed simultaneously for a smooth, proficient recovery. However, during initial training (or when your technique is rusty) a positive, confident recovery should be made "by the numbers," in the sequence given above. A very important point to remember is that the instinctive reaction to a nose-down attitude is to pull back on the elevator control. The possible result of this control response in a steep diving turn has been discussed previously.
After initial control has been applied, continue with a fast cross-check for possible overcontrolling, since the necessary initial control pressures may be large. As the rate of movement of altimeter and airspeed indicator needles decreases, the attitude is approaching level flight. When the needles stop and reverse direction, the aircraft is passing through level flight. As the indications of the airspeed indicator, altimeter, and turn coordinator stabilize, incorporate the attitude indicator into the cross-check. The attitude indicator, and turn coordinator should be checked to determine bank attitude and corrective aileron and rudder pressures applied. The ball should be centered. If it is not, skidding and slipping sensations can easily aggravate disorientation and retard recovery. If you enter the unusual attitude from an assigned altitude (either by your instructor or Air Traffic Control if operating under Instrument Flight Rules), return to the original altitude after stabilizing in straight-and-level flight.
Figure 5-41. Unusual attitude - nose high.
Common errors associated with unusual attitudes include the following
1. Failure to keep the airplane properly trimmed. A cockpit interruption when you are holding pressures can easily lead to inadvertent entry into unusual attitudes.
2. Disorganized cockpit. Hunting for charts, logs, computers, etc., can seriously detract from your attention to the instruments.
3. Slow cross-check and fixations. Your impulse is to stop and stare when you note an instrument discrepancy unless you have trained enough to develop the skill required for immediate recognition.
4. Attempting to recover by sensory sensations other than sight. The discussion of disorientation in Chapter II indicates the importance of trusting your instruments.
5. Failure to practice basic instrument skills once you have learned them. All of the errors noted in connection with basic instrument skills are aggravated during unusual attitude recoveries until the elementary skills have been mastered.
Figure 5-42. Unusual attitude - nose low.