Day 884: How A Massive Jet Plane Became A Glider

originally published June 2, 2014

To my knowledge, there has never been a commercial airline disaster on a flight that has departed from or been on its way to Edmonton, the city where my fingers do most of their keyboard-thumping. One could take that as optimistic reassurance or as a terrifying taunt to the Odds Gods, depending on one’s personal perspective. But I recently learned that my city’s perfect streak of flight safety was very nearly foiled in 1983.

It was Flight 143, a routine flight from Montreal that was run every day. The aircraft was a top-end Boeing 767, a model which hadn’t yet seen two years in the air. The plane wasn’t shiny-new, but it was new enough that mechanical trouble should not have been a concern. In this case it was, though the technical flaws on the plane were minor compared to the very human glitch of not pouring enough fuel into the tank.

Flight 143’s tale is terrifying, but it’s a triumph of pilot awesomeness that prevents it from being a tragedy. Canadian aero-lore calls this the story of the Gimli Glider. I call it the near-miss bullet that almost pierced my city’s pristine record of commercial air safety.

The fuel tanks of a 767 are regulated by the Fuel Quantity Indicator System (the FQIS). There are two channels which cross-check with one another, though the plane could be flown with either of them failing. If the FQIS fizzles entirely, the fuel gauges in the cockpit don’t work. I’m no pilot, but I suspect this would be kind of a big deal. On this particular aircraft, the FQIS was half-functional, but due to a sequence of botched last-minute maintenance (which made it non-functional) and faulty communication between ground crew and air crew, the flight was allowed to proceed.

To calculate how much fuel would be needed to get to Edmonton, pilot Bob Pearson and the Montreal ground crew had to do a little math. They crunched the numbers and determined that 22,300 pounds of fuel should do the trick. This calculation was done and redone – all with meticulous precision, except for one small catch: the conversion rate was wrong. Boeing 767’s were the first aircraft to be outfitted for the metric system, to which Canada was presently in the process of converting. The correct amount of fuel they’d require was 22,300 kilograms, not pounds. They had roughly half that. You can see how this might cause an issue.

Captain Pearson, along with First Officer Maurice Quintal, boarded the plane with full awareness of the glitchy FQIS. They guided the plane through takeoff and bumped it up to about 41,000 feet. It was smooth sailing until they were over Red Lake, Ontario – just shy of the Manitoba border and roughly halfway through their voyage. That’s when the warning system beeped, advising Pearson and Quintal there was a fuel pressure problem on the left side of the plane. No problem, they simply turned off what they assumed was a defective fuel pump; in the air, gravity would take care of feeding fuel to the engines.

Then another alarm sounded, indicating a similar failure to the right engine. Now the pilots elevated their internal threat level to ‘uncomfortable’, and requested an emergency landing in Winnipeg. That’s when they were both surprised by an unfamiliar – and ominously loud – bonging sound. It was a total engine failure. Time to ascend from ‘uncomfortable’ to ‘pants-poopingly worried’.

Then came the next problem.

The magnificent new Boeing 767 also featured an Electronic Flight Instrument System, which meant that most cockpit controls and gauges operated on power that was generated by the plane’s engines. No engine power, no cockpit power. A few things still worked, but some of the more important doohickeys – like the vertical speed indicator, which tells the pilot how quickly the plane is plummeting toward the earth – were out. The two pilots hadn’t been trained on this sort of flukey disaster, and even the operations manual included nothing about how to land without engines. By now, even the 61 passengers on board had to be freaking out. Luckily, Captain Bob had a plan.

He happened to possess hundreds of flight-hours in glider aircraft, and felt he could successfully maneuver the plane safely to the planet’s surface using those skills. First Officer Maurice may or may not have been on board, but it was their only shot so he set about calculating their chances of making it to Winnipeg in one piece. Those numbers didn’t work out in their favor. Luckily, Maurice remembered he’d been stationed at a Royal Canadian Air Force station in Gimli, which was very much within reach. If they could make it to that base – which was now closed – they could land on the runway.

Except…

Yes, RCAF Station Gimli was now Gimli Motorsports Park, and that day they were hosting a massive race event held by the Winnipeg Sports Car Club. The decommissioned runways had become a racing track and a parking lot full of cars, trucks and RVs. It would have to be cleared in time for the plane’s arrival.

As the folks on the ground frantically tried to get the hell out of the way, Captain Bob dropped the landing gear. Naturally, because nothing was destined to work right that day, the front gear didn’t lock into place – they’d had to use a gravity drop, since the hydraulic deployment system was dependent on the now-dead electrical power supply. As they approached the runway, it became clear that they were moving too fast. They were also too high, though not high enough to execute a 360-degree circle to buy time and slow down.

Captain Bob executed a forward slip – a glider technique that involves tilting into the wind while raising the opposite wing. This maintains the craft’s trajectory while using air resistance to cut down the speed. It’s a standard glider move, but not so easy to translate to a 767. Luckily, Captain Bob was one kick-ass glider pilot.

Without functioning flaps, without a proper landing gear, and without a whole lot of hope that they’d make it out alive, Captain Bob touched down and immediately stood up on the brake pedals. This blew the rear tires right away. The nose wheel, which had never clicked into place, collapsed into its wheel well, causing the nose of the plane to bounce and scrape along the runway. This turned out to be a good thing – had the nose wheel locked into place, they probably never could have slowed the plane down in time to keep from flying off the runway toward the auto racing crowd.

As it is, friction did the job. They slowed to a halt, and apart from a small nose fire and about ten minor injuries as people tried descending the inflatable emergency slides (keep in mind, the rear of the plane was tilted way up in the air now, as there was no front wheel), everyone was fine.

Air Canada blamed the pilots and ground crew, however the Aviation Board of Canada pointed their bureaucratic finger at the airline. Pearson and Quintal were suspended, though they appealed that. They were reinstated, and even worked together on a later flight. The plane – now known as the Gimli Glider – was repaired and put back to work, finally retiring to the Mojave Desert in 2008. A huge celebration was held for the plane’s decommissioning, including a Gimli parade and an invitation for Pearson, Quintal, and three of the flight’s six flight attendants to take the plane’s final voyage to its resting place in Arizona.

It was likely the most terrifying day in the lives of everyone involved, yet through the mastery of the flight crew, everyone survived. And my city’s record remains clean.