Better Training/Techniques Needed for Unusual Attitude Recovery

Air Safety Week, August 16, 1999

"The 'pull reflex' can be a fatal instinct." Don Wylie, president, Texas Air Aces Inc.

SPRING, Texas - Advice to pilots: putting your feet on the instrument panel while leaning back to relax during a quiet phase of the flight is asking for trouble. How ready are you going to be should the airplane hit a pocket of clear air turbulence?

Advice to manufacturers: it may not be a good idea to build airplanes with convenient footrests on the instrument panel.

These are just a couple pearls of concern, gleaned from a lifetime of flying and an intense study of in-flight upsets that have caught many a pilot unawares, and killed more than a few, according to Don Wylie, president of Texas Air Aces, Inc. Wylie has crafted an advanced maneuvering program to help pilots be "alert to danger" and to arm them with the skills to recover an aircraft that has been flipped or placed into what is delicately known in the trade as an "unusual attitude." To set the terms of reference, an unusual attitude is defined in the industry as one where pitch unintentionally exceeds 25 degrees nose up or 10 degrees nose down, bank angle unintentionally exceeds 45 degrees , and the airspeed is inappropriate for the conditions. Wylie believes this definition is incomplete. "My definition adds that the situation is not anticipated, and has never before been seen or experienced by the pilot," he said. Further, it's not just inappropriate airspeed, but inappropriate airspeed and angle of attack (AOA) that more properly describe an unusual attitude or upset. Angle of attack is the relationship of the relative wind to the chord of the wing and has no regard to the orientation of the nose to the ground. While many accidents are attributed to a "failure to maintain sufficient airspeed," the more salient issue in Wylie's assessment may be "failure to maintain proper angle of attack." Departures from controlled flight may be the number one continuing challenge for air safety. According to widely-accepted industry statistics, over a 10-year period from 1987-1996 more people in North America were killed by loss of control (LOC) in airline accidents than by what is perceived as the biggest killer, crashes involving controlled flight into terrain (CFIT). The CFIT toll was 312, but the deaths from loss of control totaled 482, a body count that is some 50 percent higher.

For multi-engine jets, encounters with aircraft wake turbulence outnumber by a factor of 2-to-1 incidents of loss of control from severe weather turbulence. Other causes include icing, windshear, mechanical failures, pilot inattention, pilots overcontrolling, overshooting turns on final, or following simulator habits that can be deadly in some situations.

Wylie cites two cases where the ingrained, innate response of most pilots, when the airplane is banked steeply and the noise is pointed sharply down, is to pull back on the yoke in a desperate attempt to avoid impact with Mother Earth.

Such was the case in the fatal 1994 crash of USAir Flight 427, a B737, near Pittsburgh. Although the initial factor was an encounter with the wake vortex of a B727 a few miles ahead, Wylie is less concerned with the possibility of a rudder reversal, which was the primary suspect. He points to the known fact (from the flight data recorder) that the yoke was pulled full aft in a death-grip for the final 14 seconds of the airplane's flight, while the airplane was experiencing stall buffets approaching 4G's in intensity (a demonstration flight on one of Wylie's T34 aircraft illustrated to a lesser degree the rocking, disconcerting intensity of what the USAir pilots were experiencing). Yet, according to Wylie, had the crew been trained to push the yoke forward, to restore an angle of attack that would have gotten them out of the stall, the crew may well have been able to recover the airplane (see ASW, March 15).

The crew of a China Airlines 747SP on a 1985 flight over the Pacific to Los Angeles was luckier. At 41,000 feet the number four engine experienced a compressor stall. After it was shut down, the autopilot began compensating for the yaw created by the asymmetric thrust from the remaining three engines. However, the yaw pushed the aircraft into a roll. Over the next two minutes, the airplane plummeted 32,000 feet (about six miles), rolling some 60 degrees to the right with the noise pointed nearly straight down. The crew throttled the remaining three engines to idle power and pulled back on the yoke. Passing through 30,000 feet, at some 295 knots indicated airspeed (the 747SP has a design maneuvering airspeed, Va, of some 230 knots IAS), the captain was pulling 5 G's on the airplane, and the stresses literally were pulling pieces off. Fortunately, he was able to pull the airplane out of the dive at 9,500 feet. The much-relieved crew climbed back to 27,000 ft. and limped to a diversionary landing at San Francisco.

Post-incident inspection revealed loss of the entire left elevator, most of the right elevator and the outer 30-32 feet of the horizontal stabilizer. Reportedly, the auxiliary power unit (APU) mounted in the tail had been ripped off the airplane under the high G loading and today rests at the bottom of the Pacific Ocean.