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Aviation Human Factors Industry News

July 20, 2006

Vol. II, Issue 25.

TSB Final Report A03P0332—Maintenance Error—In-flight Fuel Leak

On November 6, 2003, an Airbus A330-300 departed Vancouver International Airport, B.C., at 14:23 Pacific Standard Time (PST) on a scheduled flight to Calgary, Alta., with 6 crew members and 92 passengers on board. Shortly after takeoff, the Vancouver tower informed the pilots that a substantial amount of smoke or vapor was coming from the No. 2 engine. Although the pilots did not receive any abnormal engine indications or cockpit warnings, they declared an emergency and advised that they were returning to Vancouver. After an uneventful landing, the pilots shut down the No. 2 engine. Aircraft rescue and firefighting (ARFF) services, following the aircraft, advised the pilots that fuel was leaking from the engine but there was no sign of fire. Eventually, the aircraft was towed back to the terminal where the passengers were deplaned. There were no injuries or damage to the aircraft.

Visible fuel leak from the Airbus A330

Findings as to causes and contributing factors

      1. Because of an incorrect entry on the maintenance office duty board, and because technicians did not follow the troubleshooting manual (TSM), they unnecessarily removed the low-pressure (LP) fuel line from the fuel/oil heat exchanger.

      2. Because the technicians were unfamiliar with the coupling, because the retainer was hidden from view, and because they did not refer to the aircraft maintenance manual (AMM), the technicians did not properly reconnect the LP fuel line.

      3. Upon the application of take-off power, the fuel pressure, the fuel flow rate, and engine vibration caused the fuel/oil heat exchanger LP fuel line to detach, causing a substantial fuel leak from the No. 2 engine.

Findings as to risk

      1. A high-power engine run was not performed by the operator (nor was one required by the engine manufacturer), which would have produced conditions similar to those that caused the LP fuel line to detach from the fuel/oil heat exchanger on takeoff. A high-powered engine run could decrease the risk that a leak or mis-installed component would go undetected.

      2. Correct inspection of the fuel/oil heat exchanger would require the use of an elevated platform both prior to and after the actual engine run-up. A proper inspection of the LP fuel line connection was not accomplished after the engine run-up, increasing the risk that a leak or mis-installed component would go undetected.

      3. The operator had not implemented Airbus Service Bulletin (SB) A330-28-3080. Implementing this SB would reduce the risk that a fuel leak could go undetected, leading to fuel exhaustion, engine failure, or fire.


Other finding

      1. The removal and re-installation of the fuel/oil heat exchanger LP fuel line was not documented, as required by the operator's maintenance policy manual and Transport Canada regulation.

Poor Maintenance Endemic to Air Cargo Operations

Ten months after the death of a cargo pilot in a crash in which he was the only one aboard, the FAA revoked the carrier’s license. A number of FAA reports indicated inadequate flight personnel, and shortcomings in training and maintenance at Las Vegas-based American Aviation. Although a 2001 FAA inspection report warned, "This operator needs to be watched closely," the company continued to fly despite documented deficiencies, including the failure to give pilots the required uninterrupted rest. The death of Perry Grant flying a Piper PA-34 was the catalyst that provoked the FAA to finally revoke the carrier’s license. The case is one of a number discussed in the final part, appearing July 11, of a three-part series in The Miami Herald concerning the safety of air cargo operations. The article maintains that a culture of risk prevails in the air cargo industry, with older planes, less-experienced pilots, longer hours, overnight flying and dangerous weather. The article does not point out the lack of FAA oversight of cargo flight operations and maintenance, which some experts say is another risk factor that should be factored into a dismal safety record where about one cargo plane falls from the sky each month. The newspaper’s series on air cargo operations, titled "Deadly Express," appeared just before National Transportation Safety Board (NTSB) hearings into the safety of air cargo operations. The NTSB hearings are slated for July 12 & 13.


Man dies after walking into helicopter rotor

A Waverley man died yesterday when he walked into the spinning tail rotor of a helicopter on a farm.

Ronald Derek Heal, 61, died at the scene following the 10.50am accident on Waipipi road, the Taranaki Daily News reported today.

Wanganui Sergeant Kevin Smith said it appeared Mr Heal had walked over to the machine, while it was being loaded with fertilizer, and got too close to the spinning rotor.

Electrical Arcing Caused Fuel Tank Explosion

The National Transportation Safety Board (NTSB) is assisting the Indian Directorate of Civil Aviation in the investigation of the explosion on a Transmile Airlines B727 at Bangalore. Investigators found evidence that dangerous electrical arcing caused the explosion that destroyed the structural integrity of the left wing. On May 4, 2006, the left wing fuel tank exploded as the Malaysian-registered freighter was waiting to be towed. Investigators found evidence of damaged wiring and electrical arcing in an aluminum conduit running inside the tank. The conduit carried 115 volt AC electrical power to the fuel pump. Wire arcing within the conduit was previously recognized as a potential ignition source, and the accident airplane had been modified in accordance with an FAA airworthiness directive (AD). The AD required removal of the wires from the conduit, inspection, and re-installation of the wires, or replacement wires, into the conduit after insertion of a protective plastic sleeve. The AD actions proved insufficient to prevent the Bangalore accident. Had the explosion occurred in flight, catastrophic failure of the wing would have resulted in the airplane crashing


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Evidence of electrical arcing of the wiring inside the exploded fuel tank is shown by the circles in these photographs.


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Accident airplane.

View inside fuel tank.

UK AAIB urges action to improve wiring safety

Agency awaits full response

The AAIB’s progress report says the European Aviation Safety Agency (EASA) has replied to the circuit breaker proposal, saying: "EASA continues to be an active participant in the ageing systems rulemaking process. Industry continues to develop arc fault circuit breaker technology. A regulatory impact assessment will need to be performed before action may be taken."

The AAIB classified EASA’s response as "partially accepted, open"

while the US Federal Aviation Administration’s is "reply awaited, open". The same classification is accorded to another recommendation to the FAA: "It is recommended that the [FAA] accelerate the publication and adoption of the guidance material produced by the Ageing Transport Systems Rulemaking Advisory Committee on developing an electrical systems standard wiring practices manual, developing an effective wiring systems training programmed and on changes to existing maintenance practices and analysis methods, which could be applied to both in-service aircraft and new designs, to ensure adequate consideration is given to potential in-service deterioration of electrical wiring systems."

Aviation safety agencies on both sides of the Atlantic are moving too slowly on improving electrical wiring safety in older aircraft, says the UK Air Accidents Investigation Branch (AAIB). In its first progress report to the European Aviation Safety Agency on the status of follow-up actions recommended in accident/incident reports, it calls on both the European Aviation Safety Agency (EASA) and the US Federal Aviation Administration to "expedite a requirement for the replacement of existing thermal/mechanical type circuit breakers [CBs] by arc fault circuit breakers".

The AAIB says it is aware that plans are in progress through both agencies to reduce the likelihood of damage to old wiring looms, but since this will never be completely effective the introduction of more sensitive "intelligent" circuit breakers that recognize momentary arcing is the most critical part of the solution, it insists.

Checking progress on its recommendations from reports on four serious incidents in 2002 and 2003 – three of them to Boeing 737s and one to a Concorde – the AAIB says: "However strenuous the efforts to avoid design and maintenance quality lapses, their essentially random natures make them very difficult to eliminate. There are many reports of wiring loom damage where sustained arcing within/between looms occurred, or probably occurred, where [thermal/mechanical] CBs have failed to operate, or to operate in sufficient time to prevent serious wiring damage and, in some cases, loss of the aircraft. The four incidents reported here present such examples of sustained arcing."

The lost aircraft were a Trans World Airlines Boeing 747-100 in July 1996 and the September 1998 Swissair Boeing MD-11.

China sets up aviation safety academy

BEIJING, (Xinhua) -- China's aviation sector, the fastest growing in the world, established the China Civil Aviation Safety Academy here on Wednesday.

Yang Yuanyuan, director of China's General Administration of Civil Aviation said safety is an important criteria in judging a country's aviation development.

With a growing air transportation, it is crucial for China's aviation sector to improve its safety so as to move into a higher level of development, Yang said.

The academy will offer the staff in China's air transportation sector eight courses from theoretical studies to practical operations.

Wang Changshun, president of the academy, said although its accident rate is lower than the international average level, China's aviation industry still has a long way to go to catch up with countries with advanced aviation transportation systems.

Wang said that the academy will endeavor to set up a complete series of courses on aviation safety in five years and aim to provide 6,000 and 8,000 training opportunities for aviation staff every year.

Statistics show that China's total air transportation grew by 18.2 percent, passenger traffic by 16.5 percent and cargo transportation jumped 15.6 percent annually from 1978 to 2004, nearly double worldwide growth.

Pilots May Have Mishandled Airbus Brakes in Siberia Crash

Investigators are looking into whether the crew of an Airbus jet that went off a runway in Siberia on July 9 may have improperly used a braking system that was partly disabled before takeoff, people with knowledge of the inquiry say.

The model involved in the crash, the Airbus A310, has a thrust reverser on each of its two engines, and normal procedure, as with other large jets, is that after touchdown the crew deploys the reversers, which direct jet blast toward the front of the plane, to assist the wheel brakes in slowing the plane down. After the thrust reversers are deployed, the crew applies the throttles on the engines.

But the plane in the accident, flown by a Russian airline called S7, began its overnight flight from Moscow with one of its thrust reversers disabled.

While the reason is not clear, there are a number of causes, including mechanical failure, that could disable a thrust reverser.

Planes can land safely without thrust reversers, but if only one is deployed and power is applied to both engines, the forces are applied in opposite directions, tending to spin the airplane. Normal procedure is to alert the crew to important items that are not working, including thrust reversers.

Planes are permitted to fly disabled thrust reversers for a limited time before they are repaired.

In Irkutsk, the plane ran off the runway and ripped through a six-foot concrete barrier, slammed into several small buildings, and burst into flames, killing 124 of the 203 passengers and crew aboard.

Survivors were quoted as saying that the plane’s engines appeared to be accelerating, then shut down. That would be normal in any landing in which both thrust reversers were used.

Investigators said that in some circumstances, a pilot could use a single thrust reverser, providing that power was applied only to that engine.

Several witnesses were reported to have seen the plane actually accelerate after landing before leaving the runway and slamming into the concrete wall at about 100 miles an hour, then hitting several unoccupied storage buildings and stopping in flames.

Investigators examining the flight data recorder have not reached any definitive conclusions about the cause of the crash. It appeared, according to one investigator, that while both engines gained power after touchdown, the one without the thrust reverser gained power more slowly.

The authoritative journal, Flight International, reported Tuesday that the aircraft had landed at the proper point on the runway, then continued down the runway for some distance before yawing off to the right.

"This has led to speculation among Russian pilots that there might have been asymmetric thrust reverser deployment or braking, but no official sources will confirm or deny it at this stage," the publication said.

The two pilots, Sergei Shibanov, 45, and Vladimir Chernykh, 48, had no previous accidents, the airline said, and were highly experienced pilots qualified to fly international flights.

The benefits of breakfast

A healthy breakfast that includes high-fiber cereal can not only help keep diabetes, heart disease, and stroke at bay, it can also help you achieve and maintain a healthy weight.

Research suggests that breakfast eaters are leaner than those who skip the morning meal, with one study reporting that missing breakfast was associated with a fourfold increase in the risk of obesity. High-fiber cereals are central to breakfast's health benefits and can help you reduce the risk of heart disease, stroke, diabetes, and even intestinal polyps and colon cancer. Look for breakfast cereals that provide at least 6 grams of fiber per serving, but make sure your choice is low in sugar (less than 10 grams per serving). Add nonfat milk and bananas, berries, or apple slices to create a tasty meal.

You needn't limit your morning menu to high-fiber cereals, but wise choices are important. Stick to whole-grain or pumpernickel breads for toast; opt for trans-fat-free soft margarines or cholesterol-lowering spreads that contain plant stanols. Eggs needn't be banned from the breakfast table, but are better reserved for the occasional brunch, particularly for people with diabetes. In one study, men with diabetes who ate more than one egg a day were twice as likely to develop cardiovascular problems. To date, there is no solid evidence that organic eggs or brands high in omega-3 fats offer any particular health benefits—and they still count as eggs. Many typical breakfast foods (hash browns, bacon, croissants) have too much fat or salt—and fast-food breakfasts have too much of everything, except the fiber that adds the real punch to breakfast's health benefits.

A little experimentation—a whole grain cereal one day, pumpernickel toast with peanut butter the next—can help you find the combination of foods that make breakfast a welcome start to your day.

END with appreciation to jetBlue