By Keith Laing - 02/08/13 12:25 AM EST
“The traveling public’s safety is our highest priority," LaHood and Huerta continued. "These test flights will be an important part of our efforts to ensure the safety of passengers and return these aircraft to service.”
The battery failure that resulted in a fire was followed by a separate incident in which smoke was seen in-flight on another 787 that had a similar battery issue, causing the FAA to order U.S. airlines to take the planes out of service.
Other worldwide aviation agencies quickly followed the FAA's lead, resulting in a worldwide grounding of the Dreamliner.
The National Transportation Safety Board (NTSB), which is conducting a separate review of the 787, has attributing the battery failures to short-circuiting and accelerated temperature increases known as “thermal runaway.”
The NSTB raised questions earlier on Thursday about the FAA’s initial certification of the 787's battery, saying that “the assumptions that were used to certify the battery must be reconsidered."
"Boeing assessed that the likelihood a smoke emission event from a 787 battery would occur less than once in every 10 million flight hours," NSTB Chairwoman Deborah Hersman said during an update at the agency's headquarters in Washington.
"The 787 fleet has accumulated less than 100,000 flight hours, yet there have now been two battery events, results in smoke, less than two weeks apart, on two different aircrafts," Hersman continued.
Boeing later defended its testing of the 787’s batteries, arguing that its examinations of potential problems with the batteries had been “rigorous.”
"The 787 was certified following a rigorous Boeing test program and an extensive certification program conducted by the FAA,” Boeing said in a statement.
"We provided testing and analysis in support of the requirements of the FAA special conditions associated with the use of lithium ion batteries," Boeing continued. "We are working collaboratively to address questions about our testing and compliance with certification standards, and we will not hesitate to make changes that lead to improved testing processes and products."
The FAA did not comment on its initial certification of the 787 battery, but the agency said Thursday that “test flights are commonly used as part of research and development.
“In this case, the primary purpose of the test flights will be to collect data about the battery and electrical system performance while the aircraft is airborne,” LaHood and Huerta said. “As with all test flights, these will be subject to a number of restrictions, including extensive pre-flight testing and inspections and in-flight monitoring in order to ensure the highest levels of safety. The flights will be conducted in defined airspace over unpopulated areas.”
Boeing said in a statement after the FAA’s announcement that it was “confident that 787 is safe to operate for this flight test activity.
“The company has marshaled an extensive team of hundreds of experts and they are working around the clock focused on resolving the 787 battery issue and returning the 787 fleet to full flight status,” Boeing said. “We are working this issue tirelessly in cooperation with our customers and the appropriate regulatory and investigative authorities.”
The FAA has not identified a time frame for the resolution of its 787 investigation.
The NTSB, which has said its investigation will have no bearing on the 787’s return to operation, predicted that the conclusion of its review is "probably weeks away.”