As Ethiopian Airlines and other Boeing 787 customers prepared to return their Dreamliners to service with battery system modification kits, the U.S. National Transportation Safety Board (NTSB) conducted an exhaustive, two-day investigative hearing into the design and certification of the lithium-ion batteries implicated in the airplane’s grounding. Sixteen witnesses testified and answered questions during the hearing on April 23 and 24 at the Board’s Washington, D.C., headquarters.
U.S. National Transportation Safety Board (NTSB) members and technical specialists questioned representatives of Boeing and the Federal Aviation Administration on Tuesday about assumptions they made in determining the probability of lithium-ion batteries failing on the Boeing 787 Dreamliner.
A new aluminum-lithium foundry in Issoire, France, opened March 26 by aluminum specialist Constellium embodies the latest effort to regain ground lost to composite materials in aircraft construction. Dedicated to a new line of alloys dubbed Airware, the new casthouse has the capacity to produce 14,000 metric tons of aluminum-lithium per year, making it the world’s first large-scale production facility of the alloy.
Boeing executives expressed what they consider a “reasonable expectation” that the 787 Dreamliner would return to service in a matter of a few weeks at a briefing last Friday in Tokyo during which they detailed the company’s plan for certifying a solution to the “issues” surrounding the airplane’s lithium-ion batteries. However, Boeing Commercial Airplanes CEO Ray Conner and 787 chief program engineer Mike Sinnett acknowledged that the timing will depend completely on the U.S. Federal Aviation Administration’s certification schedule and a smooth execution of the testing.
The U.S. National Transportation Safety Board (NTSB) continues to focus on the design, certification and manufacturing processes of the lithium-ion battery system used on the grounded Boeing 787.
Whenever the non-aviation media gets hold of a story that involves aircraft certification issues, such as the recent Boeing 787 lithium-ion battery problems, an enterprising reporter “discovers” that the FAA applied “special conditions” to the certification of the product in question. These stories seem to imply that the manufacturer was given some sort of special dispensation, a way to get around the regulations to obtain the FAA’s stamp of approval.
Only one business jet thus far has been certified with a lithium-ion main-ship battery, Cessna’s Citation CJ4, which employed lithium-iron phosphate technology, unlike the lithium-cobalt oxide chemistry in the Boeing 787 batteries. No other business jet has been certified with a lithium-ion main-ship battery, although Gulfstream had planned to employ a lithium-ion battery in the G650 before switching to a nickel-cadmium battery while the aircraft was still working its way toward certification.
The International Civil Aviation Organization approved a temporary ban on carrying lithium-ion batteries as standard cargo on passenger aircraft last week. An interim amendment approved on February 13 rescinded ICAO’s earlier exemption that allowed lithium-ion batteries weighing up to 35 kg (77 pounds) to be carried. Batteries weighing approximately 66 pounds were responsible for two recent fires aboard the now-grounded Boeing 787 airliner.
Airbus has decided against using a lithium-ion main ship battery for the A350 XWB following the findings by the U.S. National Transportation Board of short-circuiting and “thermal runaway” in the APU battery that caught fire on January 7 in a Japa