Guy Norris Los Angeles

If the Jan. 7 fire on a Japan Airlines 787 at Boston's Logan International Airport proved anything to Boeing, it was that no amount of exhaustive pre-service testing can guard against the unexpected.

It also showed that the 787 remains under unprecedented scrutiny. Even with deliveries well underway and the aircraft performing better than specification, the market reaction to the Boston event demonstrated that the whole company still catches a cold when the program so much as sneezes. The smoke had barely cleared before Boeing's stock began a slide that within hours saw more than $2.6 billion temporarily wiped off the value of the company.

The question now facing Boeing and the regulators is whether the latest incident, which was centered on a lithium-ion battery unit, is more serious than a sneeze and could be the possible trigger for a system modification or redesign. The fire caused “severe fire damage” to the aft electrical/electronics (E/E) bay in which the battery—one of two on the 787—is located, states the NTSB, which is heading the investigation.

The powerful battery is designed to start the auxiliary power unit (APU) and provide back-up lighting power. The Japan Airlines (JAL) 787, which was delivered on Dec. 20, had been on the ground for around 25 min. when smoke was detected in the cabin. Airport firefighters responded and extinguished the fire in 40 min. Although Boeing is not discussing details of the Boston incident while investigations continue, Mike Sinnett, 787 vice president and chief project engineer, says the decision to use lithium-ion technology “was the right choice for us at the time. Knowing what I know now, it would be the same choice.”

The fire caused a media furor not only because it was the latest in a series of electrical system-related issues to dog the 787 in recent weeks, but also because it concerned the lithium-ion battery, the use of which was flagged by the FAA in 2007 as a special condition for certification.

Earlier electrical system issues were focused on a rash of problems in a power distribution panel which began on Dec. 4, when a United Airlines 787 was forced to divert to New Orleans. Further problems with the same system were later reported by Qatar Airways and LAN.

However, for all the attention given to these and other early in-service problems, such as leaks in the fuel system addressed by a recent FAA airworthiness directive, Boeing is adamant that the 50-strong 787 fleet is performing to a similar reliability level as the 777 was at this early stage in its service life. It also says dispatch reliability rates are better than for some other early Boeing model fleets. The number of electric-related issues appears to be worse than it is simply because the 787 is the world's first more-electric aircraft and therefore has a disproportionate number of these systems compared to other models, the company avers.