Boeing unveiled its fix for its troublesome 787 battery on Friday and is aiming to wrap up testing within two weeks.
The company hopes to get quick approval from the Federal Aviation Administration and bring an end to the grounding of the plane that began on Jan. 16. Company executives said the plane could be flying again within weeks, although aviation authorities in the U.S., Japan and elsewhere will ultimately decide the timing.
Boeing still doesn't know the root cause of the fire on a parked 787 Dreamliner in Boston on Jan. 7, or of the smoldering battery that forced an emergency landing on another 787 nine days later. Boeing executives said they may never know.
Instead, they're building a battery they hope cannot burn.
The battery's eight cells will each be wrapped in an orange tape that won't conduct electricity. A glass laminate sheet protects the cells from the aluminum case. The wires on top are getting extra heat-resisting insulation. And the whole works now goes inside a new sealed steel tub that looks like a kitchen trash can tipped on its side. If a cell overheats, a titanium hose will carry the gases to the outside of the plane through a new inch-and-a-half hole in the fuselage.
The changes make it "very unlikely" that another battery event will happen, said Ron Hinderberger, a Boeing vice president for engineering.
Boeing hopes the new steel box won't just contain a battery fire, but will prevent one from starting at all by choking off the flow of oxygen and venting the battery gases and air outside the plane.
The new design was tested before Boeing proposed it to the FAA. It will be retested so it can be certified for use on the plane, and then approval will be up to FAA.
AT A GLANCE
Boeing Co. is proposing several changes to the battery on its 787 Dreamliner. Here's a closer look at its plans, which still require government approval:
• Nonconducting tape wrapped around each of the eight cells that make up a battery.
• Heat-resisting insulation for wiring.
• Glass laminate plates between the cells and aluminum case.
• Locking nuts on the metal plates that connect each cell.
• New tests on each battery cell, and on the assembled battery.
• New sealed steel box to house the battery.
• Titanium tube to take gases from an overheated battery straight outside through a new hole in the plane.