mandag 4. august 2014

Batterier som sikkerhetsfaktor

In-flight battery fires stir safety questions


By: ANDY PASZTOR

LITHIUM batteries that power the ubiquitous electronic devices passengers take on-board planes pose an increasing, but little-publicised fire hazard.

Comprehensive data on how often there are problems with the batteries in flight aren't available but experts say that each year, carriers confront several dozen serious, in-flight instances of smouldering, smoking or even burning batteries inside aircraft cabins worldwide.

In the US alone, the Federal Aviation Administration's website lists 17 significant incidents on passenger planes in the past decade, including an American Airlines jet that had a fire in an overhead compartment last September and made an emergency landing en route from Chicago to St. Louis. There were no injuries.

With more than 1.3 billion rechargeable batteries manufactured annually around the globe and many travellers routinely bringing multiple personal devices into aircraft cabins, safety experts agree the potential for trouble is escalating.

As power packs grow more powerful, they present greater challenges if something starts heating up in the overhead bin or some device casually slipped into the seat pocket suddenly begins to spew smoke or fumes.

Such events constitute one of the big emerging safety questions facing the industry. "Batteries are a big deal" and airborne cabin incidents involving them "clearly are big issues," according to Nancy Graham, the top safety official at the International Civil Aviation Organization, an arm of the United Nations.

"We don't have enough data" yet to make long-term policy decisions, she said, adding that "industry needs to help us understand and measure what the risks are."

This week the US Department of Transportation issued new standards for air-cargo shipments of various types of lithium batteries, including packaging requirements and safeguards for power cells that have been damaged or are headed for recycling.

The rule, however, stops short of imposing limits advocated by pilot-union leaders on how many batteries or cellphones can be carried on a US cargo aircraft. US regulators don't allow lithium batteries to be shipped in the cargo holds of passenger jets, but many other countries permit such packages.

As part of the rule - slated to go into effect early next year - regulators embraced industry positions and dropped earlier proposals for more-stringent package-labelling requirements, verification of manufacturing-quality controls and classification of lithium batteries as hazardous goods.

Among the senior ranks of Google executives, according to industry officials, the emerging threat was considered real enough to prompt swift action. The company, these officials said, recently moved to equip jets that fly its executives with portable, fire-resistant aluminium sleeves.

Dubbed "PlaneGard," they also include gloves, a visor and a system to keep toxic fumes from spreading - all designed to protect passengers and crew from overheating batteries and help extinguish fires by pumping water into the sealed receptacle.

Other companies previously offered protective systems, but Michael Gilchrist, a Highwater partner, said "it's certainly a red hot topic now." He said the company is talking to airlines and corporate fleets, adding "we have seen a tremendous amount of attention."

Safety advocates say battery hazards are underreported and few carriers highlight the topic in passenger-safety cards or during briefings by flight attendants.

Air France, Cathay Pacific and Virgin Atlantic are among the handful of airlines that have gone the furthest to alert crews, provide protective equipment or explicitly warn passengers about potential risks.

Airliners have been diverted for battery problems, but there is no case of a commercial aircraft crashing due to a battery fire.

Sometimes, even airline-accident investigators get involved. French authorities issued a formal incident report about a fire in the business section of an Air France Boeing 777 in December 2010, while it was cruising at 38,000 feet across the Atlanticto Paris from Atlanta. A battery was crushed and burst into flames after getting jammed in a seat mechanism.

Such events could prompt revised firefighting procedures. So far the focus has been on keeping burning batteries, which can reach 1,000 degrees Fahrenheit, in one place. But many air safety experts now are considering if the new systems warrant changes.

An FAA spokeswoman said "we will update our firefighting and fire prevention guidance as new technologies become available."

The FAA also said that the new fire-suppression systems were still early in the development process, and the agency continues to work with ICAO, other regulators and industry representatives to "address the threat of aeroplane fires, including those associated with personal electronic devices."

Keeping track of cabin events is particularly tough. Unlike cases of in-flight entertainment systems heating up, there aren't any established, industrywide procedures for tracking similar battery malfunctions related to mobile phones, laptops, tablets or the many devices they power.

After a fire is put out using a Halon extinguishing agent, current US and international safety documents call for dousing overheated batteries with water, and instruct crew members to avoiding picking the batteries up or moving them. Experts agree ice should never be used to cool a burning or smouldering battery, because it will serve as insulation and increase the likelihood of a flare-up.

Cathay Pacific, which ships huge volumes of batteries out of China, has what is widely regarded as the industry's most extensive safety programs for cargo and passenger flights, according to independent safety experts. The Hong Kong-based carrier, among other things, tells passengers on its website to check if their carry-on lithium batteries meet UN test specifications. For spare batteries packed in checked-in luggage, the airline requires them to be protected from damage or short-circuits.

In an April 2013 presentation to an industry conference, Cathay's general manager of corporate safety reported a cellphone "was so red hot it started smoking" earlier that month on a regional airline flight between two Australian cities. The device "had to be dropped to the floor of the cabin shortly after landing," according to his PowerPoint presentation.

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