By PAUL KORING

From Thursday's Globe and Mail

Even with a serious leak in its right-side engine, Air Transat Flight 236 should not have lost all its fuel last week — unless massive amounts of fuel were pumped from the undamaged left side to the engine with the leak, sources close to the investigation say.

The Air Transat A330 Airbus was forced to make an emergency landing without power in the Azores last Friday. The emerging scenario that investigators are considering, as yet unconfirmed by detailed information from the flight data recorder, is that the pilots pumped fuel to the leaking side, turning a serious but not life-threatening situation into a near-disaster that was averted by their skilled emergency landing at a military air base with both engines out.

The Air Transat pilots were exhaustively interviewed by investigators after the incident. Air Transat declined to comment Wednesday on whether its pilots cross-fed fuel from the left-wing tanks to the leaking right engine.

"The pilots probably know, but I can't answer that right now," said Seychelle Harding, spokeswoman for the Montreal-based charter airline. She said the pilots "didn't know where the leak was until the plane was on the ground."

Ms. Harding also said the crew "followed the proper checklist."

Officials investigating the mishap will want to determine whether Airbus instrumentation could lead pilots to misdiagnose a serious fuel leak to one of the plane's Rolls Royce engines and whether the appropriate procedures were followed by the pilots.

Meanwhile, Airbus Industrie issued an alert Wednesday ordering all airlines flying A330s with Rolls-Royce engines to conduct an urgent inspection within 72 hours to ensure that all fuel lines are properly installed.

Without actually fingering Air Transat, which installed a new right-hand engine on the A330 only four days before the near-disaster, Airbus said the airline had only "partially applied" previously issued instructions. The result was the fuel pipe reconnected to the new engine chafed against a hydraulic pipe, leading to a crack and severe leak, Airbus said.

Air Transat declined comment on the Airbus assessment or its directive that all airlines check A330s with Rolls Royce engines to insure adequate separation between the fuel and hydraulic lines.

"That's what Airbus says. ... I can't comment until the investigation is complete," Ms. Harding said Wednesday.

The pilots, hailed as heroes for managing to land their powerless airliner with 291 passengers and a crew of 13, held a news conference in Mirabel, Que., earlier this week.

"There's no way to get fuel from one side to the other without opening the cross-feed," said one source, who has intimate knowledge of A330 design and flight procedures.

The cross-feed allows pilots to correct imbalances in fuel loads. It is initiated by the cockpit crew, which starts the pumps to transfer fuel.

The Airbus checklist for correcting a fuel imbalance — as opposed to its procedures for isolating a fuel leak — calls for a pilot to cross-feed fuel to the lighter wing and expressly warns against cross-feeding in the event of a leak. There are dozens of checklists for coping with different problems.

Like all modern jetliners, the A330 has established procedures to follow in the event of fuel leaks. The tanks have valves to isolate sections of them and reduce loss. If the leak is in or near the engine, as was the case with Flight 236, the fuel pumps feeding the engine should be shut down.

As well, a shut-off valve in the engine can be closed, although the fuel leakage would not stop if the crack were upstream of the valve. Shutting off that valve also shuts down the engine.

Pilots are often reluctant to shut down a malfunctioning engine, preferring to let it idle so it can be used without the restart procedure.

In the case of Flight 236, both engines were kept running until they failed within 13 minutes of each other. Investigators have determined that both failed because of "fuel starvation."

Experienced pilots say that a serious fuel leak in or near an engine should be dealt with by shutting down the engine and the pumps that feed fuel to it. That standard operating procedure applies not just to A330s but to all modern, multi-engine jetliners.

Flight 236's pilots said the aircraft had used a normal amount of fuel until about two-thirds of the way through its overnight Toronto-Lisbon flight. Then, at about 5 a.m. local time, with Lisbon still more than 1,600 kilometres away, they noticed serious fuel loss.

Twenty-five minutes later they requested a diversion to the Azores. An hour later, the aircraft had no fuel left, the second engine quit and the crew, still about 180 kilometres from Lajes air base, had to glide to a heavy but successful landing.

An Airbus 330 burns about five tonnes of fuel an hour in high-altitude cruise. According to one source, Flight 236 lost nearly 12 tonnes of fuel, much of it from the undamaged left side, in 30 minutes; total fuel loss was greater than 20 tonnes.

Although the fuel system on modern jetliners is complex, with two main tanks in each wing and often a centre fuselage tank and a tank in the tail for trimming the aircraft, the principle underlying the design is simple: to separate the left and right sides of the system so a single leak anywhere cannot result in the loss of more than half the remaining fuel. Only by transferring fuel can the reserves in the undamaged side leak out.

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> the digital flight data recorder (DFDR) is powered by AC BUS 1 in

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>[end quote]

DFDR AC Bus 2

FDIU AC Bus 2

QAR AC Bus 1

LA DC Bus 1 (3 axis linear accelerometer)

By Frances Fiorino/Aviation Week & Space Technology

31-Aug-2001 9:48 AM U.S. EDT

NEW YORK - The Aug. 24 shutdown of both 71,000-lb.-thrust Rolls-Royce Trent 700 engines on an Air Transat Airbus A330-200 transiting the Atlantic Ocean stunned industry--and promptly stirred regulators, airlines and manufacturers to action, initiating engine and fuel system inspections and probes of training and maintenance practices.

Mechanic warned Air Transat over jet

A senior airline mechanic told his boss an Air Transat plane was not ready

to fly just days before it lost power over the Atlantic, forcing a dramatic

emergency landing on an island airstrip, a union official says.

The mechanic was so worried about the plane that he tape-recorded a

telephone conversation with his non-union supervisor, who overruled his

advice to leave the Airbus A330-200 on the ground after an engine

replacement in which not all work recommended by the manufacturer was

completed, the official said.

"He didn't want to release the plane," said Jean Jallet, president of Lodge

1751 of the International Association of Machinists and Aerospace Workers,

which represents mechanics at Transat's Mirabel hangar north of Montreal.

Five days later, after several uneventful round trips, the plane's engines

died en route from Toronto to Lisbon after losing fuel. Its pilot was forced

to make a dangerous no-power landing on an island

runway to save the lives of the 304 people on board.

Air Transat spokeswoman Seychelle Harding said she couldn't comment on the

union's allegations, but she said the mechanic's supervisor was suspended

with pay last week.

"Whether something went wrong or not, he was in charge of the engine

change," Ms. Harding said. "It's standard procedure to suspend him."

Neither the airline nor the union would release the names of the mechanic or

his superior.

The cause of the near-disaster is under investigation. The Globe and Mail

quoted sources last week as saying improper installation caused a fuel line

to chafe against other pipes, resulting in a leak that

eventually starved the engines of fuel.

The engines' manufacturer, Rolls-Royce, also issued a statement last week

saying the fuel leak appears to be the result of Air Transat following only

part of a service bulletin issued earlier.

Mr. Jallet said the certified aircraft technician and his team of between

six and eight mechanics tried to follow that bulletin, which called for

replacement of the engine's fuel line and a nearby hydraulic pipe. But the

hydraulic line couldn't be corrected because certain parts weren't stocked

at the maintenance facility north of Montreal.

"That's why you'd get what what we call fretting, or chafing of the lines,"

Mr. Jallet said. "The mechanic was well aware that the service bulletin was

half-done. I don't know why they didn't have all the parts."

Mr. Jallet said an Air Transat supervisor disregarded the mechanic's concern

and signed off on the plane's release into regular service.

"My guy [the mechanic] did the right thing," Mr. Jallet said. "When they

tell you something you don't agree with, you have to call them back and get

it on tape. That way you're covered."

The union has offered lawyers to the mechanic to help him through the

Mr. Jallet also said management officials overrule unionized mechanics far

too frequently at small airlines such as Air Transat.

"In these smaller outfits, you get more pressure to release the aircraft,"

Mr. Jallet said. "You wouldn't have that at Air Canada."

Another union official said staff at smaller carriers can feel pushed to

avoid delaying planes over safety concerns.

"Probably there is more pressure because they have to meet a schedule," said

Jack Quinn, chief steward of IAMAW Lodge 764 in Richmond, B.C. "It's not

like Air Canada where you just bring another aircraft in. It's very

competitive, of course. For somebody like Air Transat, if that aircraft

doesn't fly you're looking at a whole flight being lost and people being put

up in hotels and such. I don't think they have as many backups."

Mr. Quinn, who started as a mechanic for the former Canadian Pacific

Airlines in 1977, represents West Coast mechanics of the former Canadian

Airlines, now part of Air Canada. He has no direct knowledge of Air Transat,

but said it's not a good sign if mechanics have started taping their

conversations with management.

"That's a new one on me," he said. "If you got to the point where you were

having to record things, then you would be a bit concerned, wouldn't you? It

would tell me that it wasn't the first time. I think you'd be covering your

butt."

Mr. Jallet said the mechanics union was merely doing what is necessary to

keep front-line workers from taking the fall for the airline's problems.

"It's easy to blame the lower guy on the totem pole."

The airline has said it replaced the engine because tiny metal filings had

been detected in the motor's oil. While any fuel leak is serious, this one

affected only the right-wing fuel tanks. Investigators are trying to

determine whether the pilots pumped fuel from the undamaged left-wing tanks

to the leaking right engine, causing both engines to quit.

Although the Portuguese-led investigation isn't complete, Transport Canada

has ordered Air Transat pilots to take remedial training in fuel management

and emergency procedures for long flights over water. The regulator also

directed the Montreal-based airline to overhaul its maintenance procedures.

The pilots' first remedial sessions on fuel management will begin Tuesday.

Whatever the cause of the near disaster, pilots around the world marvelled

at the skill of Captain Robert Piché in handling the plane after the second

of its two engines went silent at 34,500 feet, 137 kilometres from the

nearest airstrip. Without power, a pilot has just one chance to land. Eight

of the plane's 10 tires blew under extreme emergency braking, without

reverse engine thrust, but everyone aboard survived.

Air Transat issued a news release on the weekend detailing arrangement made

for passengers. Their airfare was refunded and they will get "complimentary

upgrades wherever possible" on the return trip, the airline said.

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