Boeing completed the set of tests required by the Federal Aviation Administration for its 787 Dreamliner battery fix with a two-hour test flight Friday.
The FAA will examine the test data from Boeing, and is expected to approve the outcome soon and let the 787’s return to passenger service.
Boeing wouldn’t submit the data unless the results had met the requirements set in advance by the FAA, so approval to allow the 787 to fly passengers again is all but certain.
Boeing clearly thinks so.
The company has lined up a series of crack mechanic teams ready to travel across the globe and retrofit on each grounded jet two seriously upgraded lithium-ion batteries.
“One of the teams has already deployed,” said Boeing spokesman Marc Birtel, though he added that the mechanics will not perform any battery work until the solution is certified by the FAA.
Even in normal times, Boeing has so-called Airplane-On-Ground, or AOG, teams ready to travel anywhere in the world where a customer’s jet is grounded.
This time, the teams will arrive with complete new battery kits. Each upgraded battery will have a stainless steel containment box and a one-inch-diameter titanium tube for venting any gases if overheating occurs.
For each of the batteries on any jet – one forward, just behind and below the cockpit; and one aft, just behind and below the wing – the AOG mechanics will have to drill a new hole in the fuselage and connect the venting tube to that outlet.
Birtel said the AOG teams are “prepared and equipped to support the implementation of approved modifications to the in-service fleet of 787’s.
“AOG teams provide the unique capability for an on-site, comprehensive and integrated modification to airplanes,” he said.
Most of the tests required by the FAA were completed on the ground, either in a lab or in a test plane parked at Paine Field.
Besides the outer containment box and the venting tubes, the new battery system includes high-temperature phenolic glass laminate dividers and clear electrical tape around each of the eight lithium-ion cells to provide both heat and electrical insulation.
To ensure the steel enclosure box can deal with even the worst-case battery-overheating incident, one test Boeing conducted entailed igniting propane gas within the box to cause an explosion that had to be completely contained.
The flight test Friday – a straight shot west across Washington state’s Olympic Peninsula, south along the coast, then back along the same path to Everett, Wash. – was more routine.
Birtel said the intention was “to demonstrate that the new system performs as intended during normal and non-normal flight conditions.”
The “non-normal” testing involved “simulating failed engines, generators, pumps and other equipment on the airplane,” he said.
All Nippon Airways and Japan Airlines should be first in line for the battery retrofits, though for those airlines, the timing must also await approval from Japan’s Civil Aviation Bureau.
Typically, the Japanese regulator, like aviation regulators worldwide, will simply go with whatever decision is made by the FAA.
Given the serious financial pressure on All Nippon Airways in particular – it’s had 17 Dreamliners grounded for close to three months – an industry source in Japan, who asked not to be identified, said Japan’s Civil Aviation Bureau will likely follow the FAA quickly.