COVER STORY The 156-tonne GIMLI GLIDER PHOTO : COURTESY ARCHIVES OF MANITOBA Grounded: Inspecting the damage after Flight 143’s unorthodox landing. It’s the 20th anniversary of aviation’s most famous deadstick landing. piloting Flight 143 on a routine flight loss of pressure in the right main fuel Merran Williams from Montreal to Edmonton, via tank. Realising the situation was becom- N THE WESTERN side Ottawa. The Boeing 767 was lightly ing serious, Pearson quickly ordered a of Manitoba’s idyllic loaded, with 61 passengers and five crew. diversion to Winnipeg Airport, 120 miles Lake Winnipeg lies an Flight 143 climbed to its cruising alti- away. It became clear they were running old Royal Canadian Air tude of 41,000 feet and the first hour of out of fuel. Force station. As a town flight was straightforward for the experi- The left engine was the first to flame ofO just 2,000 people, Gimli is a tiny dot enced flight crew. However, just after out. At 2021, when their altitude was on the map, eclipsed by its larger neigh- 2000 local time, Pearson and Quintal 28,500 feet and they were 65 miles from bour, Winnipeg. But thanks to a 20-year- were shocked to see cockpit instruments Winnipeg, the right engine stopped. old accident, Gimli is probably the most warning of low fuel pressure in the left Flight 143 was gliding. Most of the famous landing ground in Canada. fuel pump. At first they thought it was a instrument panels went blank as they On July 23, 1983, Captain Bob Pearson fuel pump failure. had been relying on power generated by and First Officer Maurice Quintal were Seconds later, warning lights indicated the engines, and suddenly Pearson was 22 FLIGHT SAFETY AUSTRALIA JULY-AUGUST 2003 Sideslipping a 767 COVER STORY Aircraft too high. Speed slowed to 180 knots flying blind. A magnetic compass, an out, the absence of a nose wheel saved artificial horizon, an airspeed indicator lives. The pilots were shocked to see peo- and an altimeter were the only instru- ple on the runway as they descended. ments still working. Unknown to Air Traffic Control, Gimli The ram air turbine dropped from airbase had become a two-lane dragstrip. near the right wheel well and used wind The rally spectators were startled to see power to turn a four-foot propeller, pro- a huge aircraft bearing down on them, viding enough hydraulic power to silent except for the rushing of wind manipulate the ailerons, elevators and against its body. People scattered as rudder. However, the pilots were unable quickly as they could, but only the fric- to operate speed brakes, flaps or the tion between the aircraft nose and the Pilot initiates slideslip. Left undercarriage or carry out reverse thrust ground as the partly extended nosewheel rudder pedal on landing. collapsed, brought the aeroplane to rest pushed while he At 2031, realising Flight 143 did not in front of them. turns the yoke to have enough height to reach Winnipeg, The time was 2038 hours. Just 17 min- the right. Aircraft the pilots called Winnipeg Air Traffic utes had elapsed since Pearson had start- manoeuvred into a steep angle, Control to request a change in heading ed flying a powerless 767 from 28,500 Aircraft rapidly to Gimli, a decommissioned airforce feet to a safe landing. loses altitude. base 12 miles away. Gimli wasn’t listed Pearson and Quintal became in Air Canada’s manuals but, fortuitous- overnight celebrities and Gimli a house- ly, Quintal had been stationed there hold name across the world. An accident when serving in the airforce. As far as that came so close to tragedy ended as a anyone knew, both of its 6,800-foot run- triumph of human ingenuity. ways would be deserted. But while the crew of Flight 143 were As the aircraft descended without praised for their skill and bravery under power, Pearson needed all his flying skills pressure, a vital question remained. How to keep it on track. He had only one did an aircraft as advanced as a Boeing Aircraft chance to land – there could be no 767, with all its cutting edge avionic straightened up at altitude 40 missed approach. Unfortunately the air- technology, run out of fuel? feet. craft was coming in too fast and was A federal government public inquiry going to overrun the runway at its cur- carried out a comprehensive investiga- rent speed, as there was no way of apply- tion into the accident, using reports ing reverse thrust. compiled by Air Canada and the Pearson took a gamble that the 767 Transportation Safety Board of Canada would respond in the same way as a (TSB). Pearson himself was on the wit- smaller aircraft and executed a sideslip ness stand for five days and remembers by turning the yoke to the right at the seeing seven television cameras trained same time as he jammed his foot against on him amid the media frenzy on the the left rudder pedal. The aircraft first day. responded and descended enough to The reason for the accident turned out Aircraft touches down. bring it in on target. The manoeuvre to be all too familiar. Systemic problems required exceptional piloting skills as the with Air Canada training and proce- indicated airspeed wasn’t correct during dures, had led to a series of uncorrected the sideslip because the angle of the air- errors by ground and flight crew. The craft was different from its direction of TSB’s final report, a tome of almost 200 ILLUSTRATION travel. It came down to Pearson’s judge- pages, criticised Air Canada’s upper ment and experience as a glider pilot. management for serious communication Aircraft comes to During the nerve-wracking descent, failures. The TSB concluded that pro- : rest PETER MARKMANN Quintal tried using a back-up system to ducing manuals and procedures for per- lower and lock the landing-gear. The sonnel was a “corporate responsibility” gear on each wing was deployed but the not being adequately fulfilled by Air nosewheel stuck part way. As it turned Canada management. FLIGHT SAFETY AUSTRALIA JULY-AUGUST 2003 23 GIMLI RED LAKE WINNIPEG MONTREAL OTTAWA Cut short Travelling from Montreal to Edmonton via Ottowa, Flight 143 was forced to divert to Winnipeg because of a fuel shortage that led to the loss of both engines. When it became apparent the aircraft would not reach Winnipeg, the pilots changed course and headed to Gimli. The flight and cabin crews were Although he couldn’t diagnose the praised for averting a major disaster “The failure of one exact problem, Yaremko found that if he through their “professionalism and skill” disabled the faulty circuit breaker, the which helped them overcome the prob- inductor coil should not backup circuit breaker got the gauges lems caused by “corporate and equip- working again and provided the required ment deficiencies”. have disabled the fuel fuel readings. The mechanic labelled the The trouble started almost three weeks pulled circuit breaker with yellow main- before the accident when the fuel quanti- gauges.” tenance tape to prevent it being turned ty indicating system on aircraft No. 604 back on. But he did not clearly record in (later Flight 143) was examined follow- the logbook his reasons for doing this. ing a directive from Boeing. As each fuel self-testing mechanism enabling it to The 767 flew from Edmonton to gauge was checked, it mysteriously went recognise faults within the system. Montreal via Ottawa without incident blank. However, a later check found the These built-in redundancies did not after the pilot in command satisfied him- gauges apparently working normally, so prevent the processor from failing, how- self that it was legal to operate the air- the aircraft was given clearance to fly. ever. Tests performed after the accident craft under provisions of the Minimum On the night of 22-23 July, the prob- found the failure was caused by a “cold Equipment List (MEL) despite the devia- lem resurfaced and the same mechanic, solder” joint on the inductor between tion reported in the fuel processor. Conrad Yaremko, investigated, unaware one coil wire and its terminal post. While Because of the unreliable electronic it was the same aircraft. He discovered a the terminal post was pretinned and had fuel monitoring system, when the air- malfunction in the digital fuel gauge enough solder sticking to it, the coil wire craft reached Dorval Airport in processor but was told no replacement end was not pretinned and had poor Montreal, maintenance worker Jean processors were available. adhesion. Ouellet was assigned to conduct a manu- The processor was a dual-channel sys- Still, the failure of one inductor coil al drip check of the aircraft’s fuel levels tem that provided fuel quantity meas- should not have disabled the fuel gauges. before its dispatch to Edmonton. He was urement, calculation and indication, and Another inductor coil in the second intrigued by the problem with the fuel was located under the aircraft’s floor, processor should have taken over if the processor and despite not having the behind the cockpit. It was considered the processor had performed according to its authority or training, took it upon him- “heart” of the fuel quantity indication specifications. Investigations revealed a self to tinker with the electronics while system on the Boeing 767 and was built design error was to blame. The processor waiting for the fuel truck. As he later told by Honeywell to Boeing specifications. failed to switch from the defective chan- investigators: “I thought I would do a Its benefits included an ability to operate nel to a working channel because there BITE [built-in test equipment] test on on a second channel if one failed, and a had been a drop in the power supply.