POSTED AT 3:38 AM EDT    Wednesday, August 29
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Stricken jet leaked fuel after engine change
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By PAUL KORING
From Wednesday's Globe and Mail

 

A fuel line that failed on an engine that had been changed only days earlier caused an Air Transat Airbus A330 to lose huge amounts of fuel, forcing an emergency landing last week, say sources close to the investigation into the mishap.

That a crucial component could fail and the crew either did not or could not stem the resulting massive loss of fuel raises grave questions regarding maintenance, design and crew performance.

Air Transat changed the right-side engine in the week before the accident, sources close to the investigation say. Changing an engine requires that the fuel line be disconnected and reconnected, and investigators want to determine whether that procedure was properly done. The aircraft had made only two or three round-trip flights after the engine swap. One source said the new engine had been on the A330 for less than 50 flying hours.

Changing airplane engines is a common and periodic maintenance procedure.

Frederico Serra, the Portuguese lead investigator, confirmed Tuesday that "both engines failed as a result of fuel starvation" and that the "fuel line on the right-hand engine had failed."

Air Transat's Flight 236, with 291 passengers and a crew of 13 on an overnight journey from Toronto to Lisbon, managed to make an emergency "dead-stick" landing last Friday at a military air base in the Azores, the only land for more than 1,600 kilometres in any direction. Fortunately, dawn had broken and visibility was good.

The pilots are being hailed as heroes for managing to land what had become a huge glider at an unfamiliar airport, but investigators will also probe how long they had known about the fuel problem and what — if anything — they were able to do to isolate the leak.

Airbus confirmed Tuesday that the A330 design — like all modern jetliners — includes valves and redundant systems that allow pilots to isolate fuel leaks and stem further losses. "If there is a problem with fuel feed, there are valves to shut off flow," said Mary Anne Greczyn, a spokeswoman for Airbus North America.

She confirmed that the A330 design allowed for leaks to be isolated whether they occurred in any of the four main wing tanks, the two trim tanks, the centre fuel-feed tank or at either of the engines. Yet Flight 236 lost at least one-third of the fuel that was loaded on in Toronto, enough to take it from Toronto to Lisbon with a reserve for flying to an alternate airport — more than 1,600 kilometres beyond the Azores.

It remains unclear how long the pilots knew they had fuel problems. Co-pilot Dirk DeJager, 28, said Tuesday that the plane had more than enough fuel to complete the flight when he checked at 4:57 a.m. Less than half an hour later, at 5:25 a.m., the pilots reported a fuel problem to Portuguese air-traffic control. That was more than a hour before the second engine failed because of fuel starvation.

The crew initially at 5:25 requested a diversion to the Azores but didn't declare an emergency. Twenty-three minutes later, with fuel still pouring from the right-hand engine, they declared an emergency. Then at 6:13 a.m. the right engine failed.

Thirteen minutes later, with the aircraft at 32,000 feet and about 100 nautical miles from Lajes airport, the crew told controllers that the second engine had also shut down. After gliding for 20 minutes, the pilots landed the aircraft heavily but safely at Lajes.

"A fuel leak in an engine is a critical failure .. which should not take the aircraft down," Daniel Verreault, director of air investigations at Canada's Transportation Safety Board, said Tuesday in an interview. Although the investigation is being led by Portugal's accident investigation authority, representatives of Canadian agencies as well as Airbus and engine-maker Rolls-Royce are accredited to the team.

Mr. Verreault said the "failure should be isolated." It is a fundamental design principle of modern commercial aircraft that no single failure of a key component should render the aircraft unflyable. "A fuel leak, regardless of location, must be able to be stopped," he said.

If the fault is found to be in the design of the A330, the entire fleet could be grounded and require retrofitting.

"If it is an issue of maintenance, it brings the issue closer to home," Mr. Verreault added.

Air Transat, which has only three A330s in its fleet of 23 aircraft, carries out its own heavy maintenance, including routine swapping of engines on the Airbus twin jets.

So far, Canadian authorities haven't found anything to suggest that the problem affected other A330s or was the result of a design flaw, although the investigation has only just begun.

"We have no reason to believe that there is any problem at this stage with the A330," Canadian Transport Minister David Collenette said Tuesday.

Transport Canada had a team of four investigators at Air Transat's maintenance base at Mirabel, Que., Tuesday conducting an audit of the airline's procedures.

Earlier, Transport Canada suspended Air Transat's authority to operate A330s more than one hour's flying time from an airport on overwater routes.

From this LINK

Airboeing
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Member # 32811

posted 29 August 2001 21:54     Profile for Airboeing   Email Airboeing     Send New Private Message   Edit/Delete Post
One thing for sure is this incident is going to lead to a radical review and overhaul of manufacturer's procedures for dealing with fuel leaks. The Boeing 757 QRH for example only speaks of an engine fuel leak and this because there have been MANY such leaks and MANY cock ups in trying to deal with the suspected leak. The actual procedure in the 757 QRH is a complete mess and written for lawyers CYA (cover yer @rse). Only after a page and one half of guff does it get to the nitty gritty and this involves shutting an engine down "conditions permitting". Assuming the leak does not show on the fuel flow meters, this is the ONLY way to determine if a leak is on the engine (downstream of spar valve) or in the tank itself. The trouble with this is that psychologically it will be very difficult to convince yourself to shutdown an operating engine with which there is APPARENTLY nothing wrong. Unfortunately there is a long history of crews opening the cross-feed valve in such circumstances and so exacerbating the problem. Please note I am not suggesting anything of the sort here but there have been several cases on Boeing aircraft where this has occurred and leading to, for example, landing with one wing tank empty and the other almost full.

The posting regarding the British reg 330 with both engines surging due to fuel starvation sounds very interesting indeed and could cast a whole new light on things.


Posts: 47 | From: uk | Registered: Apr 2001  |  IP: Logged

 

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posted 30 August 2001 06:38     Profile for kimoki   Email kimoki     Send New Private Message   Edit/Delete Post
With reference to AirBoeing's post I have always thought the A330 Fuel Leak checklist to be a can of worms. It speaks of two scenarios - "Leak from Engine" or "Leak not from Engine or Leak not Located". It is very difficult to tell which applies and normally one will follow the second procedure initially which involves keeping the cross-feed CLOSED and turning all the fuel tank pumps off to allow gravity feeding at a lower altitude. There is a note however which says that if an engine flames out then one can assume that the leak is from an engine and apply that procedure which asks you to shut the engine down and turn all the fuel pumps back on. There is a note which says "The Xfeed valve can now be selected OPEN for rebalancing or to allow use of fuel from both wings".

The logic is that when the fuel pumps are turned off then air will be sucked into the engine through the leak if the leak is close to the engine and it will flame out. Shutting down the engine involves putting the Engine Master switch (Fuel switch) to off which closes the High and Low pressure fuel shutoff valves, therefore the leak should be isolated, allowing opening of the cross-feed. Of course if the leak is upstream of the Low pressure valve then all you are now doing is pumping the rest of your fuel overboard at high pressure.

This is all speculation of course and may have no bearing on this incident. And by the way, the 330 is a great glider with a huge wing and often the problem is getting it down.


Posts: 13 | From: Sandpit | Registered: Sep 98  |  IP: Logged
McGinty
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posted 30 August 2001 15:50     Profile for McGinty   Email McGinty     Send New Private Message   Edit/Delete Post
"I also heard that the FDR and CVR have gone to France for Investigation. Is this normal? Should they not have gone to TSB or do they normally go to manufacturer?"

On the Tech Log forum I asked a question about whether the FDR and CVR would be powered by the Ram Air Turbine after the loss of both engines on the 330.
http://www.pprune.org/cgibin/ultimatebb.cgi?ubb=get_topic&f=3&t=002419

The answer that came back was "the digital flight data recorder (DFDR) is powered by AC BUS 1 in the A330-200. Hence without engine driven generators or the APU it is inoperative!"

It thus would appear (as with the SwissAir 111 crash) that there will be no data available about the extraordinary last phases of flight for the Air Transat airbus.

There will unfortunately be no record of this pilot's wonderful dead-stick landing.


Posts: 57 | From: Saskatoon, Saskatchewan, Canada | Registered: Nov 1999  |  IP: Logged
"Having studied this incident with interest, I`m going to stick my neck out and think it went like this:

Quest:   A question on qty of Fuel flow transducers. Is there one at the tank outlet and one near the engine fuel control? If so, a major discrepancy of fuel flow should ring some warning bells ( either physically or metaphorically). If it is only measuring fuel flow at the fuel control nothing would appear strange as the fuel is leaking upstream of it.

Answer:  As far as I can see from FCOM the fuel flow is only measured just prior to the injectors so there would be no warning. The FMC constantly displays the fuel on board at landing on the flight-plan page so this would be where you would first spot an anomaly. An ECAM advisory would come up once the imbalance reached 3000kgs in the inner (main) tanks.

@ 0525 they noticed fuel leak - probably by seeing an unbalanced tank. If they did the standard calculation they would have realised they were indeed losing fuel. Which checklist to use? They kept the no.2 engine running throughout so if they did a checklist it had to be the "leak not from engine or leak not located" drill. In this case the X-feed stays in AUTO i.e.closed and you descend to gravity feed ceiling FL200 and then switch pumps off. If they had identified the leak from the no.2 engine, then they would have done the "leak from engine" drill which means you shut down the engine and can then use X-feed if you want to. But they kept the no2 engine running.

Somewhere it says they lost about 20 tons and I reckon that's about right. They were approx 1hr30mins to 2hrs away from Lisbon so 20 tons at that point is not unreasonable. Remember that 6 ton of this will be in the two outer tanks and a further 2ton or so in the trim tank. That would normally leave about 6 tons in each inner tank. Obviously they had quite a bit less than this in the right inner due to the leak and, once it got below 4000kgs, the trim-tank would transfer forward all its contents. As the right inner had so much less than the left one, the trim tank fuel probably all went to the right inner - however if the X-Feed was open (to achieve some sort of balance) then not necessarily so. Once inner contents get down to 3500kgs the outer tank transfers to the inner about a further 3 tons.

So if the x-Feed had stayed closed throughout they would have had 6 tons in the inner and 3 tons in the outer = about 9 tons (plus a ton say from the trim tank) to feed the no 1 engine and plenty to cruise for 250 miles and start a descent from FL200 (the gravity fuel-feeding ceiling) on one engine. If the no2 had been shut down, they would have had loads more. But they decided to keep the no2 engine running.

The fact that both engines failed from fuel starvation within 10 mins of each other -whilst there was a massive loss on one side -means the X-Feed must have been used and would explain the rapid loss of fuel from the LHS of the system.

We may yet hear there were further system failures but I doubt it. I think it was their reluctance to shut down the no2 engine coupled with opening the X-Feed that will be their downfall.  That's v.easy to say sat here - quite another to be there at night over the Atlantic with a leaking fuel system. They DID do a good job with the dead-stick but I figure if they had just kept the X-Feed closed they would have at worst done a single-engine approach and landing. It is a neat trap designed into the aircraft and the checklists (and with a modicum of help from the automation)

 

Jet crew's handling of fuel leak questioned

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.

In spite of a serious fuel leak on one side of the twin-engined jet, the flight crew should have been able to fly the plane safely on one engine with plenty of fuel reserves unless the cross-feed pumps were engaged, sending fuel from the undamaged left side to the right-hand engine, according to senior pilots familiar with the design and operation of the Airbus A330.

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.

Veteran pilot Robert Pichι said: "I don't consider myself a hero." At the news conference, neither he nor co-pilot Dirk DeJager, 28, said what they did to cope with the leak. Even with a severe and uncontained leak on one side of the aircraft, in this case a cracked, high-volume, low-pressure fuel-feed pipe to the right-hand engine, sufficient fuel would have remained in the left-wing tanks to fly the aircraft to its destination, the sources said.

"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 source said the only way the Air Transat plane could have lost all its fuel — including the still substantial amounts in the left-wing tanks unaffected by the leak — was that it was pumped to the right-side engine.

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.

 

Today's Toronto Star reported that the fuel line is 2.5 inches in diameter and that it can not be misrouted.

It's too bad that we can't see:

1. The RR Trent safety bulletin on routing of the hydraulic and fuel lines, maybe even diagrams of correct and incorrect routing. And is this routing effected during an engine change, maintenance or assembly? Given that the engine was in storage in a common pool, there is a possibility that the service bulletin applied to engine maintenance rather than installation.
2. Where the engine fuel shutoff is placed relative to the rupture.
3. The contents of the checklists that were followed.

From what I have been able to pick up in the public domain, the leak was very heavy and likely above the fuel shutoff. It seems that checklists assume that the leak is below the fuel shutoff and that the cross-feeds can be reopened once the engine is secured. Likely, shutting off the cross-feeds would have gotten them to Lajes with one operating engine, but the volume of the leak left the crew too little time to catch on to the full extent of their problem before running out.
I speculate that the fuel pumps are designed to maintain pressure in the line so that in a heavy leak situation they happily turn up the volume until the tank goes dry.
It would be nice to have the FMC monitor engine burn vs. tank volume. That would give you a gross leakage rate. In order to pinpoint the leak, you need flow transducers in each fuel line.
With Air Transat, you suddenly have two very busy pilots in the cockpit running procedures and executing a diversion with next to no time and insufficient cockpit information to quantify or pinpoint a massive leak.


It's going to take some reengineering before a crew will be able to identify in time which valve to shut when it's a case of a massive fuel leak.

 

[begin quote]

>

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

> the A330-200. Hence without engine driven generators [or the APU] it  is inoperative

>

>[end quote]

 on later A330 aircraft electrical power supply for the flight recorders is as follows (this may or may not apply to the aircraft in question):

DFDR AC Bus 2

FDIU AC Bus 2

QAR AC Bus 1

LA DC Bus 1 (3 axis linear accelerometer)

In the event of a dual engine flameout plus APU due no fuel, none of these busses would be supplied. Incidentally, the aircraft is one heck of a good glider, and the crew did a superb job getting it down safely. If we've had spare time in the simulator recently, for a "fun" finishing item we have been looking at 2 engine out approaches, starting at 25nm finals at 7,500 feet (on the glide-slope) and minimum clean speed - and landing is no big problem. This sort of event is clearly outside any normal or abnormal certification parameters, and just "for fun".

Why both engines should fail from fuel starvation remains to be seen.

AvWeek: A330 Overwater Flameout Raises ETOPS Issues

 

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.

In the wake of the near-catastrophic event, flight safety experts can be expected to revisit all aspects of extended twin-engine overwater operations.

Just last week, Canadian Transport Minister David Collenette revealed Air Transat agreed to a request by Transport Canada to implement special ETOPS training sessions for all flight crew as well as to review proper procedures, which include fuel management and the need to divert to the nearest alternate airport at first sign of engine-related emergency. In addition, Air Transat initiated a comprehensive review of the safety of its maintenance and operations and has provided Transport Canada with a corrective action plan.

The Portuguese safety board, the Gabiente de Pevencao e Investigacao de Acidentes com Aeronaves (GPIAA), is leading the investigation, with assistance from the Transport Safety Board of Canada and DCGA, the French civil aviation authority. GPIAA's preliminary report determined that both engines failed as a result of fuel starvation, and that a low-pressure fuel line on the No. 2 engine, Rolls-Royce Trent 700 serial no. 41055, had failed "probably as a result of its coming into contact with an adjacent hydraulic line" (see p. 36).

Montreal-based Air Transat Flight TS236, an A330-200, C-GITS, departed Toronto Lester B. Pearson Airport as scheduled, at 8:10 p.m. (EST) on Aug. 23, en route to Lisbon, with 293 passengers and 13 crewmembers. The twin-engine aircraft is certified to operate under the ETOPS 120-min. rule, that is, permitted to divert with one operable engine to an airport that is up to 2 hr. away.

Flight TS236 was cruising at Flight Level 390 (39,000 ft.). At 0536Z, the flight crew became aware of a fuel imbalance between the left and right wing main fuel tanks. At about 0541Z, the crew, concerned about the lower-than-expected fuel quantity indication, elected to divert from the intended flight route to Lajes Field (LPLA), which is located on the northeast tip of Terceira Island in the Azores--850 mi. west of Lisbon.

At 0548Z, the crew ascertained a leak might be the cause of the fuel loss and declared an emergency to Santa Maria Oceanic Control. At 0613Z, with Flight 236 135 mi. distant from Lajes, the flight crew alerted air traffic control of the failure of the right Rolls-Royce Trent 772-211B engine.

About 13 min. later, about 85 naut. mi. from Lajes at an altitude of about FL345, the left engine failed. The flight crew advised ATC that ditching at sea was a possibility.

The aircraft, which has a range of 5,600 naut. mi., and can accommodate up to 406 passengers in high-density configuration, became a glider. Its fuel supply--tanks have a maximum capacity of 36,750 U.S. gal.--was apparently depleted.

The cabin crew prepared the passengers for ditching at sea and issued brace command. ATC provided radar vectors to the flight crew, who proceeded on an engines-out night visual approach in what the GPIAA described as good weather conditions--wind 330 deg. at 8 kt., visibility unlimited, few clouds at 2,500 ft. and 5,000 ft. and temperature at 19C.

When the A330 touched down on Lajes' 10,865 X 300-ft. Runway 33 at 0646Z, eight of 10 tires ruptured. The GPIAA report said small fires that started in the main gear wheels were extinguished by crash response vehicles in position at the field. "There was no evidence of fire on the engine or fuel system," an Air Transat official said.

The GPIAA said nine passengers and two cabin crewmembers received minor injuries in the emergency evacuation, which, according to Flight Director Meleni Tesic, was completed in 90 sec. Reportedly, there was no fire or smoke in the cabin.

Passengers described the landing as "brutal" and "hysterical" and some accused the cabin crew of panicking. Tesic said there "was absolutely no panic in the cabin." With no PA system, she explained, attendants must shout as loudly as possible so passengers can hear safety instructions. Some passengers may have misconstrued the shouting for panic behavior.

Capt. Robert Piche said at a press conference he was "fully confident" the aircraft was loaded with fuel when the flight departed Toronto Pearson. He said he had minimum power with which to control the aircraft on descent to Lajes.

Passengers and the public hailed the flight crew as heroes, but Piche dismissed this, saying, "I was only doing my job . . . . we train for the worst." First Officer Dirk DeJager agreed. Piche, 49, and with 30 years of airline experience has been employed by Air Transat for nearly five years. DeJager, 28, has been flying with Air Transat for about five years.

No one had to be reminded of possible endings for the TS236 story. Lajes, a U.S. air base from which air crews and support troops are deployed, has high terrain to 1,925 ft. 2.75 naut. mi. west, and 503 ft. 0.25 naut. mi. east. From October to May, strong winds create hazardous crosswinds.

Immediately following the incident, the Transportation Safety Board of Canada suspended that country's largest charter airline from operating 120-min. ETOPS for its three A330s in a fleet of 24 aircraft, and launched a special audit of the carrier's maintenance practices. It also increased surveillance of Air Transat's aviation program to ensure compliance with Canadian Aviation Regulations. "The issue is that a leak in a pipe should not result in two engine shutdowns. That is a serious concern," said TSB Chairman Benoit Bouchard.

Air Transat called the rule "normal" and "a usual procedure in this type of circumstance" and did not expect it to have more than a minor impact on day-to-day operations. The carrier is to continue to fly ETOPS under the 60-min. rule, that is, an engine-out aircraft must be no more than 1 hr. from an airport. This means Air Transat will fly routes closer to land masses.

As a precautionary measure, Air Transat completed inspections of its engines on its A330s. Air Canada, which operates eight A330s, all of which have Rolls-Royce Trent 700 engines, undertook and completed inspection of the powerplants to ensure no mechanical conditions existed of the type that may have contributed to the Air Transat emergency.

On Aug. 29, Airbus issued an AOT (All Operators Telex) to operators of Airbus aircraft equipped with Rolls-Royce Trent 700s, saying the source of Air Transat's fuel leak is "a damaged fuel feed pipe." Further, it says the damage is "due to interference with the hydraulic pipe from the aft hydraulic pump in the vicinity of the HP fuel pump inlet" and that the interference can result in "a significant fuel leak." It says the pipes are modified as part of Rolls-Royce service bulletin RB211-29-C625. Complete application of the SB would ensure adequate clearance, according to the AOT, adding that the SB appears to "be partially applied on the affected engine."

The aim of the AOT is to launch a one-time inspection of the A330/Trent 700 fleet and spare engines, to ensure there is no interference between the parts in question and to complete that inspection within 72 hr. of receipt of the AOT.

Air Transat late last week was trying to regain its equilibrium. The carrier, a subsidiary of a leading Canadian travel services company, Transat A.T., began operations in 1987. Air Transat operates charters from Canada and Europe to southern destinations. It has a total fleet of 24 aircraft, including three A330s (two -200s and one -300), four A310-300s, six Lockheed L-1011-500s, seven L-1011-10s and four Boeing 757-200s. The airline says it transported 3.5 million passengers last year.

The company has not had any accidents causing injury, nor has the aircraft involved in the Lajes occurrence been implicated in another incident. According to Air Transat President and CEO Denis Jacob, the carrier has had 54 minor events out of 2,800 listed for Canada's total air industry.

The Lajes incident, however, is the second emergency evacuation for the carrier within seven days. On Aug. 18, smoke issued from the cabin ceiling lights of an L-1011 as it taxied to the departure runway at Orlando, Fla., with 324 passengers and 14 crew on board, The pilot ordered an evacuation that resulted in a few minor injuries.

The crippled A330 sat on Lajes sole runway, forcing the airport to cease flight operations, stranding about 600 passengers, until Aug. 28, when repair crews arrived with equipment to move the aircraft.

Pierre Sparaco contributed to this report from Paris.

Aviation Week & Space Technology is the world's leading weekly source of in-depth news and authoritative analysis of aviation and aerospace technology, business and operations. Take a look at the current issue.

 

 

Unconfirmed Source.

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

investigation, Mr. Jallet said. He would not reveal the tape's exact contents.

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 Pichι 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.

The Threat to ETOPS Operations      More revelations

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