Gimli Glider

[tapakeg]

I did a search on this, and there have been some brief posts about it, but nothing this in-depth.  

Our CO sent this out to the squad, I thought I would pass it along.  If it's old news, sorry, for those of you who haven't heard of this, it is an excellent read.


The Gimli Glider  by Wade H. Nelson
>
> Copyright WHN 1997 All Rights Reserved,  Published in Soaring Magazine
>
> Question:  If a Boeing 767 runs out of fuel at 41,000 feet what do you
> have?
>
> Answer:  A 132 ton glider with a sink rate of over 2,000 feet-per-
> minute and marginally enough hydraulic pressure to control the
> ailerons, elevator, and rudder.  Put veteran  pilots Bob Pearson and
> cool-as-a-cucumber  Maurice Quintal in the cockpit and you've got the
> unbelievable  but true story of Air Canada Flight 143, known ever since
> as the Gimli Glider.
>
> Flight 143's problems began on the ground in Montreal.  A computer
> known as the Fuel Quantity Information System Processor manages the
> entire 767 fuel loading process.  The FQIS controls the fuel pumps and
> drives all of the 767's fuel gauges.  Little is left for crew and
> refuelers to do but hook up the hoses and dial in the desired fuel
> load.  But the FQIS was not working properly on Flight 143.  The fault
> was later discovered to be a poorly soldered sensor.  An improbable
> sequence of circuit-breaking mistakes made by an Air Canada technician
> independently investigating  the  problem  defeated  several  layers
> of  redundancy  built into the system.  This left Aircraft #604 without
> working fuel gauges.
>
> In order to make their flight from Montreal to Ottawa and on to
> Edmonton, Flight 143's maintenance crew resorted to calculating the
> 767's fuel load by hand.  This was done using a procedure known as
> dipping, or "dripping" the tanks.  "Dripping" could be compared to
> calculating the amount of oil in a car based on taking a dipstick
> reading.
>
> Among other things, the specific gravity of jet fuel is needed to make
> the proper "drip" calculations.  The flight crew had never been trained
> how to perform the calculations.  To be safe they re-ran the numbers
> three times to be absolutely, positively sure the refuelers hadn't made
> any mistakes; each time using 1.77 pounds/liter as the specific gravity
> factor.  This was the factor written on the refueler's slip and used on
> all of the other planes in Air Canada's fleet.  The factor the
> refuelers and the crew should have used on the brand new,  ALL-METRIC
> 767 was  0.8 kg/liter of kerosene.
>
> After a brief  hop Flight 143 landed in Ottawa.  To be completely safe,
> Pearson insisted on having the 767 re-dripped.  The refuelers reporting
> the plane as having 11,430 liters of fuel contained in the two wing
> tanks.  Pearson and Quintal, again using the same incorrect factor used
> in Montreal, calculated  they had 20,400 kilos of fuel on board.  In
> fact, they left for Ottawa with only 9144 kilos, roughly half what
> would  be needed to reach Edmonton.
>
> Lacking real fuel gauges Quintal and Pearson manually keyed 20,400 into
> the 767's flight management computer.  The flight management computer
> kept rough track of the amount of fuel remaining by subtracting the
> amount of fuel burned from the amount (they believed) they had started
> with.  Their fate was now sealed.  According to Pearson, the crew and
> passengers had just finished dinner when the first warning light came
> on.  Flight 143 was outbound over Red Lake Ontario at 41,000 feet and
> 469 knots at the time.  The 767's Engine Indicator and Crew Alerting
> System beeped four times in quick succession, alerting them to a fuel
> pressure problem.  "At that point" Pearson says "We believed we had a
> failed fuel pump in the left wing, and switched it off.  We also
> considered the possibility we were having some kind of a computer
> problem.  Our flight management computer showed more than adequate fuel
> remaining for the duration of the flight.  We'd made fuel checks at two
> waypoints  and had no other indications of a fuel shortage."  When a
> second fuel pressure warning light came on, Pearson felt it was too
> much of a coincidence and made a decision to divert to Winnipeg.
> Flight 143 requested an emergency clearance and began a gradual descent
> to 28,000.  Says Pearson, "Circumstances then began to build fairly
> rapidly."  The other left wing pressure gauge lit up, and the 767's
> left engine quickly flamed out.  The crew tried crossfeeding the tanks,
> initially suspecting a pump failure.
>
> Pearson and Quintal immediately began making preparations for a one
> engine landing.  Then another fuel light lit up.  Two minutes later,
> just as preparations were being completed, the EICAS issued a sharp
> bong--indicating the complete loss of both engines.  Says Quintal "It's
> a sound that Bob and I had never heard before.  It's not in the
> simulator."  After the "bong," things got quiet.  Very quiet.  Starved
> of fuel, both Pratt & Whitney engines had flamed out.  At 1:21 GMT, the
> forty million dollar, state-of-the-art Boeing 767 had become a glider.
> The APU, designed to supply electrical and pneumatic power under
> emergency conditions, was no help because it drank from the same fuel
> tanks as the main engines.  Approaching 28,000 feet the 767's glass
> cockpit went dark.  Pilot Bob Pearson was left with a radio and standby
> instruments, noticeably lacking a vertical speed indicator - the glider
> pilot's instrument of choice.  Hydraulic pressure was falling fast and
> the plane's controls were quickly becoming inoperative.  But the
> engineers at Boeing had foreseen even this most unlikely of scenarios
> and provided one last failsafe & emdash; the RAT.  The RAT is the Ram
> Air Turbine, a propeller driven hydraulic pump tucked under the belly
> of the 767.  The RAT can supply just enough hydraulic pressure to move
> the control surfaces and enable a dead-stick landing.  The loss of both
> engines caused the RAT to automatically drop into the airstream and
> begin supplying hydraulic pressure.
>
> As Pearson began gliding the big bird, Quintal "got busy" in the
> manuals looking for procedures for dealing with the loss of both
> engines.  There were none.  Neither he nor Pearson nor any other 767
> pilot had ever  been trained on this contingency.  Pearson reports he
> was thinking "I wonder how it's all going to turn out."  Controllers in
> Winnipeg began suggesting alternate landing spots, but none of the
> airports suggested, including Gimli, had the emergency equipment Flight
> 143 would need for a crash landing.  The 767's radar transponder had
> gone dark leaving controllers in Winnipeg using a cardboard ruler on
> the radar screen to try to determine the 767's location and rate of
> descent.
>
> Pearson glided the 767 at 220 knots, his best guess as to the optimum
> airspeed.  There was nothing in the manual about minimum sink - Boeing
> never expected anyone to try to glide one of their jumbo jets.  The
> windmilling engine fans created enormous drag, giving the 767 a sink
> rate of somewhere between 2000 and 2500 fpm.  Copilot Quintal began
> making glide-slope calculations to see if they'd make Winnipeg.  The
> 767 had lost 5000 feet of altitude over the prior ten nautical (11
> statute) miles, giving a glide ratio of approximately 11:1.  ATC
> controllers and Quintal both calculated that Winnipeg was going to be
> too far a glide; the 767 was sinking too fast.  "We're not going to
> make Winnipeg" he told Pearson.  Pearson trusted Quintal absolutely at
> this critical moment, and immediately turned north.
>
> Only Gimli, the site of an abandoned Royal Canadian Air Force Base
> remained as a possible landing spot.  It was 12 miles away.  It wasn't
> in Air Canada's equivalent of Jeppensen manuals, but Quintal was
> familiar with it because he'd been stationed there in the service.
> Unknown to him and the controllers in Winnipeg, Runway 32L (left) of
> Gimli's twin 6800 foot runways had become inactive and was  now used
> for auto racing.  A steel guard rail had been installed down most of
> the southeastern portion of 32L, dividing it into a two  lane
> dragstrip.  This was the runway on which Pearson would ultimately try
> to land, courting tragedy of epic proportions.
>
> To say that runway 32L was being used for auto racing is perhaps an
> understatement.

[tapakeg]

Gimli's inactive runway had been "carved up" into a
> variety of racing courses, including the aforementioned dragstrip.
> Drag races were perhaps the only auto racing event not taking place on
> July 23rd, 1983 since this was "Family Day" for the Winnipeg Sports Car
> Club.  Go-cart races were being held on one portion of runway 32L, and
> just past the dragstrip another portion of the runway served as the
> final straightaway  for a road course.  Around the edges of the
> straightaway  were cars, campers, kids, and families in abundance.  To
> land an airplane in the midst of all of this activity meant certain
> disaster.
>
> Pearson and Copilot Quintal turned toward Gimli and continued their
> steep glide.  Flight 143 disappeared below Winnipeg's radar screens,
> the controllers frantically radioing for information about the number
> of "souls" on board.  Approaching Gimli Pearson and Quintal made their
> next unpleasant discovery:  The RAT didn't supply hydraulic pressure to
> the 767's landing gear.  Pearson ordered a "gravity drop" as Pearson
> thumbed frantically through the Quick Reference Handbook, or QRH.
> Quintal soon tossed the QRH aside and hit the button to release the
> gear door pins.  They heard the main gear fall and lock in place.  But
> Quintal only got two green lights, not three.  The nose gear hadn't
> gone over center and locked, despite the "assist" it was given by the
> wind.
>
> Six miles out Pearson began his final approach onto what was formerly
> RCAFB Gimli.  Pearson says his attention was  totally concentrated on
> the airspeed indicator from this point on.  Approaching runway 32L he
> realized he was too high and too fast, and slowed to 180 knots.
> Lacking dive brakes,  he did what any sailplane pilot would do:  He
> crossed the controls and threw the 767 into a vicious sideslip.  Slips
> are normally avoided on commercial flights because of the the
> tremendous buffeting it creates, unnerving passengers.  As he put the
> plane into a slip some of Flight 143's passengers ended up looking at
> nothing but blue sky, the others straight down at a golf course.  Says
> Quintal, "It was an odd feeling.  The left wing was down,  so I was up
> compared to Bob.  I sort of looked down at him, not sideways anymore."
> The only problem was that the slip further slowed the RAT, costing
> Pearson precious hydraulic pressure.  Would he be able to wrestle the
> 767's dipped wing up before the plane struck the ground?  Trees and
> golfers were visible out the starboard side passengers' windows  as the
> 767 hurtled toward  the threshold at 180 knots, 30-50 knots faster than
> normal.  The RAT didn't supply "juice" to the 767's flaps or slats so
> the landing was going to be hot.  Pearson didn't recover from the slip
> until the very last moment.  A passenger reportedly said "Christ, I can
> almost see what clubs they are using."  Copilot Quintal suspected
> Pearson hadn't seen the guardrail and the multitude of people and cars
> down the runway.  But at this point it was too late to say anything.  A
> glider only gets one chance at a landing, and they were committed.
> Quintal bit his lip and remained silent.  Why did Pearson select 32L
> instead of 32R?  Gimli was uncontrolled so Pearson had to rely on
> visual cues.  It was approaching dusk.  Runway 32L was  a bit wider,
> having been the primary runway at Gimli in prior years.  Light
> stanchions still led up to 32L.  And the "X" painted on 32L, indicating
> its inactive status, was reportedly quite faded or non-existent.
> Having made an initial decision to go for 32L the wide separation of
> the runways would have made it impossible for Pearson to divert to 32R
> at the last moment.  Pearson says he "Never even saw 32R, focusing
> instead on airspeed, attitude, and his plane's relationship to the
> threshold of 32L."
>
> The 767 silently leveled off and the main gear touched down as
> spectators,  racers, and kids on bicycles fled the runway.  The giant
> Boeing was about to become a 132 ton, silver bulldozer.  One member of
> the Winnipeg Sports Car Club reported  he was walking down the
> dragstrip, five gallon can full of hi-octane racing fuel in hand, when
> he looked up and saw the 767 headed right for him.  Pearson stood on
> the brakes the instant the main gear touched down.  An explosion rocked
> the 767's cabin as two  tires  blew.  The nose gear, which  hadn't
> locked down,  collapsed with a bang.  The nose of the 767 slammed
> against the runway,  bounced,  then began throwing a three hundred foot
> shower  of sparks.  The right engine nacelle struck the ground.  The
> 767 reached the tail end of the dragstrip and the nose grazed a few of
> the guardrail's wooden support poles.  (The dragstrip began in the
> middle of the runway with the guardrail extending towards 32L's
> threshold) Pearson applied extra right brake so the main gear would
> straddle the guardrail.  Would the sports car fans be able to get out
> of the way, or would Pearson have to veer the big jet off the runway to
> avoid hitting stragglers?
>
> The 767 came to a stop on its nose, mains, and right engine nacelle
> less than a hundred feet from spectators,  barbecues and campers.  All
> of the race fans had managed to flee the path of the silver bulldozer.
> The 767's fuselage was intact.  For an instant, there was silence in
> the cabin.  Then cheers and applause broke out.  They'd made it;
> everyone was alive.  But it wasn't over yet.  A small fire had broken
> out in the nose of the aircraft.  Oily black smoke began to pour into
> the cockpit.  The fiery deaths of passengers in an Air Canada DC-9 that
> had made an emergency landing in Cincinnati a month before was on the
> flight attendants' minds, and an emergency evacuation was ordered.  The
> unusual nose-down angle at which the plane was resting made the rear
> emergency slides nearly vertical.  Descending them was  treacherous.
> The only injuries that resulted from Pearson's dead-stick landing of
> Flight 143 came from passengers exiting the rear emergency slide and
> slamming onto the asphalt.  None of the injuries were life-threatening.
>    The fire in the aircraft's nose area was battled by members of the
> Winnipeg Sports Car Club who converged on the plane with dozens of
> hand-held fire extinguishers.  Pearson had touched down 800 feet from
> the threshold and used a mere 3,000 feet of runway to stop.  A general
> aviation pilot who viewed  the landing from a Cessna on the apron of
> 32R described it as "Impeccable."  The 767 was relatively undamaged.
>
> Air Canada Aircraft #604 was repaired sufficiently to be flown out of
> Gimli two days later.  After approximately $1M in repairs, consisting
> primarily of nose gear replacement,  skin repairs, and replacement of a
> wiring harness, it re-entered the Air Canada fleet.  To this day
> Aircraft #604 is known to insiders as "The Gimli Glider."  The
> avoidance of disaster was credited to Capt. Pearson's "Knowledge of
> gliding which he applied in an emergency situation to the landing of
> one of the most sophisticated aircraft ever built."  Captain Pearson
> strongly credits Quintal for his cockpit management of "Everything but
> the actual flight controls," including his recommendation of Gimli as a
> landing spot.  Captains Pearson and Quintal spoke at the 1991 SSA
> Convention in Albuquerque about their experiences.  Pearson was, at the
> time, still employed and flying for Air Canada, and occasionally flying
> his Blanik L-13 sailplane on the weekends;  he has since retired to
> raise horses.  Maurice Quintal is now an A-320 Pilot for Air Canada,
> and will soon be captaining 767's, including Aircraft #604.
>
> Copyright 1997 WHN
>
> A side-note to the Gimli story:  After Flight 143 had landed safely, a
> group of Air Canada mechanics was dispatched to drive down and begin
> effecting repairs.  They piled into a van with all their tools.  They
> reportedly ran out of fuel en-route, finding themselves stranded
> somewhere in the back woods


and a link with a news story

Gimli Glider News Story


Could you imagine being a passenger on that plane?


Tapakeg

[Dinger]

and the subject of a made for tv movie.

this is one of my favorites. It just fires the imagination for some reason.

[rpm]

The TV movie was actually pretty good...for a TV movie.

[tapakeg]

Yeah, in searching the boards as to not re-post, that is what most people talked about was the movie.  Would be interested in watching it.  I wonder if it is a rental?


Tapakeg

[Sandman]

Cool story.

[Chairboy]

The problem with the TV movie is that it represented the crew of the plane as being lucky idjuts.  For example "What's this RAT thing?  Maybe we should press the lever and find out" and the captain jumping out of the airplane and kissing the ground.

The captain was hired to be a consultant to help with the movie, but after reading the script, he declined and required them to remove his name from the credits.

Just an FYI.

And yes, amazing piloting.  The Gimli Glider is truly one of the most incredible modern aviation stories, right up there with the DC-10 landing sans hydraulics (where the instructor who was a passenger sat between the pilot seats helping steer the plane w/ differential thrust).

[john9001]

the plane took off with inop fuel guages? remind me never to fly air canada.

[J_A_B]

"up there with the DC-10 landing sans hydraulics (where the instructor who was a passenger sat between the pilot seats helping steer the plane w/ differential thrust)."


I thought that one crashed on landing.



J_A_B

[tapakeg]

I thought that one crashed on landing.

It did, but there were survivors, and they were lucky to get the plane within 100 miles of the airport, let alone lined up on the runway.     IIRC


Tapakeg

[Chairboy]

Originally posted by J_A_B
I thought that one crashed on landing.
J_A_B

It did, and people died.  But because of the hard work of the crew members and the gentleman who helped steer the plane, there were survivors.

Sometimes life doesn't give you 100% of what you want, and you should celebrate what you get.  It's astonishing that ANYONE survived a complete hydraulic failure at altitude on a modern jet.

[tapakeg]

It is amazing to know that they KNEW of a fuel indicator problem and the aircraft was able to fly with passengers.

I woked on helicopters in the Army and believe me, that aircraft would never have left the runway.    X


I would think the standads for commercial airlines would be same if not tighter because of the number of lives flyng.

anyone been a mechanic for both military and civilian?  care to tell the difference between the standards?


Tapakeg