WASHINGTON --
Manufacture of lithium-
Federal investigators said Monday that Ion batteries allowed pollutants and other defects in the batteries on Boeing's 787 Dreamliner, including a battery that broke out in Boston's smoke and fire in 2013.
The National Transportation Safety Council is at 110-
Page reported that on January, a Japanese airline plane parked in Boston caught fire due to a short battery. 7, 2013.
This issue is due to the fact that Boeing has not been designed for the most serious impact of the short circuit, and also due to the fact that the FAA did not find this issue when it certified the aircraft, according to the NTSB report.
The exact cause of the short circuit was never found in the Boston incident or a similar smoldering battery in January.
2013, this prompted an emergency landing in Japan on a full-day air carrier flight.
But three months after the FAA stopped flying, Boeing redesigned the battery with ceramic insulation between the batteries, a steel box to hold any short circuit and a steel box that would smoke and be flammable
On March 2014, Boeing and the FAA announced that Dreamliner was safe after a full review of its certification.
The battery problem came at the time of the delivery of innovative aircraft, with 49 aircraft worldwide, including 6 to United Airlines. Lithium-
Ion batteries are common in mobile phones and laptops because they are lighter and more efficient than typical nickel
CD battery.
The battery has contributed to the Dreamliner, which is 20% more fuel efficient than similar aircraft.
But in the safety assessment of the battery, Boeing expects the battery to be discharged once in 10 million flight hours.
The problems in Boston and Japan happened after about 52,000 flying hours.
NTSB determines that the short circuit is not caused by overcharging, external short circuit, external heat, or installation. NTSB found :--
Boeing Japan sub-contractor GS Yuasa who made the battery did not test the battery in the worst possible conditions during the flight and tested the battery different from the certified final design.
Tests include pushing nails into the battery or heating the battery with an electrical pad to cause a short circuit. --
GS Yuasa's production facilities have welding that allows the potential entry of foreign debris into the battery, checking that defects such as wrinkle of battery wires cannot be reliably detected. --
The FAA did not realize that a short circuit in one of the batteries could spread to the entire battery like Boston and Japan in what is called a heat runaway.
Boston turned out to be a heat out of control, with the aircraft's auxiliary battery spewing smoke to the rear of the aircraft, and according to the NTSB report, "There are two fires of different flames at the electrical connector on the front of the Shell ".
Kenneth Quinn, spokesman for GS Yuasa, said the company respected the NTSB report, but added that "the root cause of the internal short circuit is still elusive.
"However, we are still full of confidence in the quality and safety of our batteries, our country-of-the-
"The Art manufacturing process and our highly skilled, well-trained staff," says Quinn, a Washington Airlines lawyer . ".
To prevent similar problems in the future, the board recommends :--
FAA works with industry to revise safety standards for lithium
Ion battery, with a better test to detect overheating of the battery. --
Boeing has built better oversight of its supply to ensure that industry standards are applied in manufacturing. --
GS Yuasa reviews its manufacturing to prevent defects.
Quinn said the company is keen to continuously improve quality in battery manufacturing and will look closely at the findings and suggestions of NTSB.