Air Safety Week:

Averting Catastrophe Through Superior Airmanship

Crews of two flights received ALPA's superior airmanship awards for 2003. The citations are instructive illustrations of coping under stress, not to mention intelligent improvisation for situations beyond those covered by the standard checklists. Extracts below are from the awards given to the respective captains:

Federal Express MD-11, June 16, 2002, flight from Bangkok to Subic Bay, Philippines:

"As the aircraft was nearing the turn for final approach at approximately 1,500 feet, Captain James Almlie called for 50� of flaps. As First Officer Mark Abbott selected the flap handle to that position, the crew heard a loud bang and felt the airplane immediately and rapidly roll to the left. Capt. Almlie instantly countered the uncommanded roll and leveled the wings, which required nearly full right aileron. First Officer Abbott immediately called for a go-around while Capt. Almlie fought to maintain control of the aircraft. The crew complied with the go-around procedures as best they were able, but found the outboard flaps retracted to 28� while the inboard flaps were stuck in an asymmetric position - somewhere between 41� and 50�. At the same time, the autothrottles were slow to react, requiring Abbott to manually increase and decrease power on Captain Almlie's command.

"The crew immediately diverted to Manila and completed emergency procedures ... and safely navigated the barely controllable aircraft around the mountainous terrain ... in the darkness. At one point ... the control forces required to keep the wings level became so great that Capt. Almlie had to hand over the controls to First Officer Abbott and allow himself a break before beginning the approach and landing at the Manila airport. The crew flew an approach with Captain Almlie working the flight controls and First Officer Abbott working the throttles. Working together in this unusual but effective way, [they] brought the crippled aircraft to a safe landing.

"After landing, the crew's external check of the airplane revealed that the left inboard flap had become detached from the wing due to structural failure of bolts in the attachment assembly. The violent failure severed hydraulic lines in the left wing that led to the failure of one hydraulic system. Debris from the damaged components had caused the ground spoiler system to deploy and jam in the up position, effectively destroying much of the lift on the left wing. Because of the amount of control deflection required to counter the loss of lift on the left wing, spoilers also deployed on the right wing, robbing that wing of lift as well."

The case is under investigation by the National Transportation Safety Board (NTSB), and at this point is considered a straight hardware failure, sources familiar with the case say.

Northwest Airlines, Flight 85, October 9, 2002, a B747-400, Tokyo to Detroit:

"While cruising on autopilot at approximately 35,000 feet and approaching Russian airspace over the Bering Sea, the airplane abruptly rolled into a 35� left bank. The pilots instantly countered the uncommanded bank, keeping the airplane from rolling over and diving at high speed into the ocean. The pilots assessed the situation and diverted to Anchorage, Alaska. The aircraft was hand flown for more than an hour-and-a-half while using opposite upper rudder, bank, and differential thrust to maintain aircraft control. With no procedures to guide them, the flight crew had to develop the best way to safely execute an approach and landing. (ASW note: the B747 has a two-panel rudder; in this case, the lower panel deflected fully to the blowdown limit. The crew countered the resulting aerodynamic force with the upper rudder panel.)

"At normal flap setting, the approach to Anchorage was flown at 185 knots (about 210 mph - or 60 mph faster than normal for landing). By this time, the lower rudder further deflected to 31.5�. At touchdown, the aircraft began to veer left, but by using tiller, differential braking, and differential reverse, the crew was able to keep the aircraft on the pavement. There were no injuries."

The NTSB is investigating, but at this point the uncommanded deflection of the rudder initially to 17� has been attributed to a failed power control module. Although all such modules have been inspected, an airworthiness directive (AD) is forthcoming, sources said, to further ensure the integrity of these rudder control mechanisms, as the same module moves the upper rudder panel as well.

An ALPA source familiar with this incident said the situation would have been more dire if the upper panel had been the one driven to full deflection by a failed control unit, as that panel is larger.

Capt. John Hanson, with 35 years of flying experience, was the pilot in command. Hanson, his copilot, and two pilots comprising the relief crew, all received the superior airmanship award. In radio communication with Northwest personnel on the ground, they worked out the procedures to bring the airplane to a safe landing at Anchorage. Concerns were expressed at the ALPA symposium that the procedures developed literally "on the fly" in this case need to be promulgated to the entire fleet.