Published Feb. 12, 2013
The Boeing Co. has flight tested one of its 787 Dreamliners to monitor batteries at the center of investigations that led to the airplane’s grounding.
The company’s fifth test airplane, ZA005, flew Saturday and Monday, according to a blog maintained by Randy Tinseth, vice president of marketing for Boeing Commercial Airplanes.
To see photos of Boeing’s 787 test flights, click here.
Two pilots and 11 crew members were onboard during the test flights, and ZA005 flew over eastern Washington state, barely crossing into Oregon during both flights. The crew used special equipment to monitor the main and auxiliary power unit, or APU, batteries, and the flights were the first round of monitoring tests.
Saturday’s flight lasted two hours and 19 minutes, and Monday’s flight lasted one hour and 30 minutes.
Tinseth said the data collected during the flights could help investigators looking into a battery fire aboard a Japan Airlines 787 in January at Logan International Airport in Boston and into an emergency landing in Japan that same month.
The Boston fire began in cell six of the APU battery, according to the National Transportation Safety Board. The cell short-circuited and a thermal runaway, or uncontrolled increase in heat, followed and spread to the other cells.
The battery caught fire after passengers and crew had disembarked. Maintenance and cleaning personnel found smoke in the cabin and called firefighters, who put out the fire about 40 minutes after arriving on scene.
NTSB Chairman Deborah Hersman has also said the battery’s certification process needs to be reviewed.
“Boeing has indicated that these tests showed no evidence of cell-to-cell propagation or fire in the battery,” Hersman said. “Boeing assessed that the likelihood of a smoke emission event from a 787 battery would occur less than once in every 10 million flight hours.”
But the 787 fleet has accumulated fewer than 100,000 flight hours, Hersman said, and “there have now been two battery events resulting in smoke less than two weeks apart on two different aircrafts.”
The second event happened on an All Nippon Airways 787 in Japan about a week after the fire in Boston. Japanese regulators are leading that investigation, and the battery incident forced the airplane’s emergency landing. The ANA flight was climbing at 30,000 feet when the crew noticed smoke and fumes in the cabin and flight deck. Japanese regulators haven’t characterized the issue as a “fire event,” Hersman has said.
“The assumptions used to certify a battery must be reconsidered,” she said.