While the rest of the Boeing 787 fleet remains grounded, the FAA has authorized a one-time crew-only Dreamliner flight to return one of the airplanes from a paint facility in Fort Worth, Texas, to the company’s factory outside Seattle.
FAA approval for the flight was given alongside the stipulations that the flight crew take a direct route to Everett, follow certain preflight procedures to ensure no pre-existing battery damage and continuously monitor for potential battery problems in flight.
Thursday’s ferry flight comes as investigators continue to probe the problems surrounding the 787’s lithium-ion batteries, which triggered a fire in a Japan Airlines Dreamliner parked at Boston Logan International Airport on January 7 and smoke on an All Nippon Airways airplane during a January 16 flight in Japan.
Inspection of the battery involved in the Boston incident revealed evidence of thermal runaway, a process in which a large increase in temperature triggers progressively increasing temperatures that, in this case, ultimately exceeded 500 degrees Fahrenheit.
The NTSB announced on Thursday that the battery showed multiple indications of short-circuiting in a single cell, and that investigators are looking into a number of potential culprits, including battery charging, manufacturing defects and the underlying design and construction of the battery. Mechanical impact damage and external short-circuiting have been ruled out as potential factors.
Boeing officials maintain they are confident the 787 will be able to return to the skies using lithium-ion batteries, but they say they are working on contingency plans involving conventional batteries as well.
As the NTSB and the FAA look into the cause surrounding the incidents, investigators are also taking a closer look at the Dreamliner flight test program and the approval process for the batteries in an effort to determine why the battery problems were not discovered sooner.
Prior to certification, Boeing’s test data suggested that the risk of smoke emission from a Dreamliner battery was as low as once in every 10 million flight hours. NTSB Chairman Deborah A.P. Hersman on Thursday emphasized that the possibility that short-circuiting in a single cell could lead to a critical problem must now be re-evaluated in the wake of the two recent incidents, which were experienced in a fleet that, to date, has accumulated less than 100,000 hours.
When the Boeing 787 will be able to return to the skies for battery testing remains unknown.