Air Canada 143 is surely one of the most famous aircraft disasters in the history of aviation. A brand new fly-by-wire Boeing 767-200 inexplicably ran out of fuel on a flight from Montreal to Edmonton. Thanks to a series of fortuitous coincidences and the skill of Captain Pearson the stricken plane glided to a decommissioned aerodrome at Gimli, and the powerless landing resulted in no fatalities. So was born the sensational story of the Gimli Glider
Unlike most books on catastrophic aviation incidents, William and Marilyn Hoffer concentrate their narrative on human emotion. They have clearly spent an inordinate time interviewing practically all of the 69 survivors, and through theses accounts they have authored a riveting story of the growing concern evolving into terror and then intense jubilation and relief once the plane had been landed successfully.
As with most aviation incidents, Air Canada 143's predicament was the result of a series of minor faults, both mechanical and human, which aggregated together caused a potentially lethal combination. The plane had been authorised to fly despite the Fuel Quantity Indicator System (FQIS) being non-operational. This opposed the recommendations on the Minimum Equipment List (MEL) – an evolving document full of placeholders and ambiguity due to the newness of the aircraft. The FQIS itself had dual redundancies but a dry solder joint meant this was only operating correctly when a circuit breaker was tripped. This circuit breaker had been left in the wrong position due a maintenance staff oversight. The airline had recently opted to change from imperial to metric measurements but the refuelling staff were not trained with the correct conversion factors. The Boeing required fuel by volume whilst the refuelling tankers provided it by weight – again introducing conversion errors. Finally there were incomplete procedures after the devolution of fuel sign-off from the cockpit to the maintenance engineers.
Hours into the flight and the engines flamed out, fortune changed in favour of those on board. Wide bodied 'heavies' don't glide. The best that can be achieved is a controlled descent, yet Captain Pearson was a time-served glider pilot and managed to maximise the terrain covered by the unpowered plane. Thankfully Gimli was an achievable glide distance away, and it offered an extremely long strip of asphalt by virtue of it being a WWII training airport. As the 767 'glided' towards Gimli it became clear to Pearson that he was too high and fast to make the landing. With no power to deploy the flaps and slats, and not enough altitude for a 360 degree turn, he pulled off a manoeuvre unprecedented in the history of aviation on a commercial airliner, yet commonplace on a glider. He sideslipped the behemoth using opposite aileron and rudder – this can achieve a rapid speed and altitude loss when the wing is lowered and the same amount of opposite rudder keeps the actual heading the same.
Once the plane landed Captain Pearson noticed that the far end of the runway was being used as a drag strip by a motor club, but again good fortune intervened. The forward gear on the plane collapsed resulting in increased inertia due to the friction which stopped the plane short of the partying motor club, most of which had not realised a silent wide bodied jet was careering down the runway towards them.
As stories with a human angle and a happy ending go, it would be difficult to beat the Hoffer's blow-by-blow account. The book is let down by the complete absence of schematics and diagrams, but as previous stated, the authors are more interested in those involved than recalcitrant machinery.