On Thursday the U.S. agency that investigates air crashes called for lithium-ion batteries on Boeing's 787 Dreamliner jets to undergo more testing to ensure they are safe. The 250-seat jetliner, which has a list price of around $212 million, has been plagued with problems since it was introduced in 2011.
The National Transportation Safety Board (NTSB) urged the Federal Aviation Administration (FAA) to develop better tests to evaluate and certify the batteries, which have in some cases overheated and led to battery fires.
The NTSB is also recommending that the FAA require the tests for future aircraft designs and check whether 787s and other planes that have similar batteries need more testing. The agency, which stopped short of calling lithium-ion batteries or planes flying with them unsafe, can only make recommendations — it would be up to the FAA to decide whether to act.
Lithium-ion batteries are widely used in cars, laptops and smartphones and have a tendency to overheat through processes that are not well understood by scientists.
The NTSB criticized the FAA, Boeing and battery-maker GS Yuasa Corp of Japan. Recent NTSB tests showed results are affected by environmental factors, such as how the battery was installed and the temperature of the air around it. The testing protocols for the battery, however, were "inadequate" because they didn't properly account for real world conditions.
"There is no standardized thermal runaway test that's conducted in the environment and conditions that would most accurately reflect how the battery would perform when installed and operated on an in-service airplane," the NTSB said on its website.
The NTSB has not yet determined a root cause for the 787 fire of a parked Japan Airlines plane in Boston in January 2013. No one was injured in the fire, but the incident prompted aviation authorities at the time to ground the approximately 50 Boeing 787 planes that were in service globally.
That grounding lasted for three months while Boeing designed a steel containment box and other measures to stifle battery fires on the jet. The FAA later approved a battery redesign plan by Boeing and the planes have since been allowed to fly once again, but safety concerns remain.
Other incidents followed, including a Japan Airlines plane that had to be temporarily grounded at Tokyo's Narita International Airport after white smoke was spotted outside the plane and a battery cell showed signs of leaking in January.
In calling for the changes before its fire investigation ends, the NTSB signaled safety could be improved and pressed the FAA to proceed without delay.
In a 12-page letter, the NTSB said it sought "to urge the FAA to take action" on its five recommendations, which include seeking advice from independent experts on new technologies well before they're authorized for use on aircraft.
Boeing said it supported efforts to improve certification standards, while the FAA was not immediately available to comment.
Boeing also said the tests it conducted in overhauling the 787 battery system last year "are fully consistent with the recommendations made by the NTSB today."
Hans Weber, a former FAA adviser and president of consulting firm TECOP International, said the NTSB's recommendations were important to ensuring safety.
"It's a professional, serious step in dealing with new technology that has resulted in some scary failures," Weber told Reuters. "Whether the FAA acts on this one or not remains to be seen."
The NTSB also urged development of new tests that simulate an aircraft environment. While the NTSB's letter focused on Boeing's 787, they also noted the Airbus A380 and Boeing 777 and 737 also have lithium-ion batteries.
Al Jazeera and wire services