Boeing Dreamliner Fire: No Cause Found
The US National Transportation Safety Board (NTSB) has released the findings of an investigation into the battery fire on a Boeing 787 in January.
But its 547-page report failed to identify the root cause of the blaze on a Japan Airlines Dreamliner at Boston's Logan International Airport.
The regulators said firefighters struggled to control the battery fire through thick smoke after a ventilation system failed due to the lack of power.
The 787's auxiliary power unit - an engine in the tail of the plane - was also shut off because the battery is needed to start the system.
Initial attempts to remove the smoking 28kg battery from the plane failed, but it was eventually lifted to around 15 metres away from the plane.
One firefighter was injured in the attempts to put out the fire - which took one hour and 40 minutes in total, the report said.
A second incident, nine days later, in Japan prompted the grounding of all Dreamliners, costing Boeing and airlines millions of pounds a day.
US aviation officials are expected to make a decision in the near future about whether to approve a plan by Boeing to revamp the 787's lithium ion batteries to prevent or contain future fires.
If approved, the company hopes to test the reconfigured batteries quickly and have the planes back in the air as soon as possible.
The company described the NTSB's report as a "positive step" towards completing the investigation and a spokesman said it had worked closely with the regulators.
The report comes as a Japanese transport ministry official said authorities knew of past incidents involving circuit boards on Dreamliners operated by All Nippon Airways (ANA).
But they do not believe the problems are linked to the jet's battery problems, he added.
ANA, which owns nearly half of the 50 Dreamliners delivered to date along with Japan Airlines, said there had been three instances of electric distribution panel trouble in its 787s before it was grounded.
what do you think?
The investigation into the cause(s) of a fire developing in a lithium-ion battery could usefully focus on variability of the environmental conditions in which the battery operates, and in particular the cyclic nature of those variations. Assuming that the battery is not within the temperature and pressure controlled cabin area, then it is possible that it is subject to dramatic variations of temperature, pressure, and humidity. It is also possible that these variations occur over a large range in a very short period of time. If this happens several times a day, it may be that using such batteries in these conditions is just asking for trouble. Lithium-ion batteries have been around for years; in fact most consumer-market cameras and camcorders use such batteries. They are not noted for catching fire, but then the environmental conditions under which they operate are within a restricted range and change relatively slowly. Let's not forget that Comet airliner crashes in the early 50s were due to cyclic pressure variations which caused cracking of the skin of the fuselage.