It appears – two years after Boeing had fire incidents from installed lithium ion batteries that shut down deliveries of its vaunted Dreamliner 787 – that its “solution” to “vent” heat and flames outside the aircrafts has prevented any catastrophes, so far.
But it hasn’t alleviated concerns about the batteries’ physics and makeup. Last week Boeing issued a warning to its airline customers to not carry bulk shipments of lithium-ions because if they catch fire or overheat, they’re unstoppable. A spokesman told the Associated Press that the manufacturer has advised airlines not to transport the batteries “until safer methods of packaging and transport are established and implemented.” Likewise, the FAA simultaneously stated that its research has found that carriage of lithium ion batteries “presents a risk.”
The alert was industry-wide. At a safety forum held last week in Washington by the Air Line Pilots Association, Boeing’s fire protection system specialist Doug Ferguson explained what led to the decision to issue the warning. He said standard fire suppression systems employed on aircraft, called Halon 1301, are ineffective against the “thermal runaway” that bulk quantities of lithium ion batteries are known for.
“Unrestricted quantities of lithium batteries that are involved in a cargo fire…can still create hazards that would effect the continued safe flight and landing of the aircraft,” Ferguson said, “particularly depending on the location, the type and quantity of batteries and the time required for a safe landing.”
Boeing, after dismissing any fears about fires in the lithium-ion batteries that power most of the Dreamliner’s systems (saying “it almost doesn’t matter” what caused them), apparently had an intervention from a higher power. According to Aviation International News, the International Coordinating Council of Aerospace Industries Associations issued recommendations regarding transport of lith-ions. Boeing and fellow manufacturers Airbus, Embraer and Bombardier participated in developing the advisory, with plans to meet soon to work on packaging that can contain or mitigate thermal runaway fires.
“What has happened,” Ferguson added, “is that testing has shown that there are higher rates of smoke production, flammable vapor, pressures and temperatures that occur with fires that involve…lithium-ion batteries….than with ordinary Class A type combustibles – paper products for instance.”
So did Boeing learn something new all of a sudden? Or was the company pressed by industry groups to align with them over their serious concerns about the dangers of lithium-ion batteries? According to a physicist who has closely followed the Boeing situation, and battery fires in general, the dangers of bundled lith-ions and the shortcomings of Halon are nothing new.
“It was already very well-known 5 years ago that Halon has no chance whatsoever to extinguish a fire involving significant numbers of Lithium-ion batteries in air cargo,” said Lewis Larsen of Chicago-based Lattice Energy. “The notion that it would take yet another 5 years for this particular epiphany to finally dawn on them is simply not believable.”
At the safety forum Ferguson said in testing, the Halon controlled flames, but the thermal heat that migrated from battery to battery was unaffected. It’s a phenomenon with which Ferguson and Boeing’s safety team should be well experienced. Two Japanese airlines suffered battery fires on Dreamliners in January 2013, which spurred the Federal Aviation Administration to shut down operations while the incidents were investigated. And in 2006 a 787 battery explosion caused a “devastating lab fire” in Arizona, burning a 10,000-square-foot facility to the ground.
Two years ago Larsen said debris from a thermal runaway event on a Japan Air Lines Dreamliner showed that heat from internal shorts reached temperatures far higher than Boeing engineers likely contemplated in their design. The evidence showed that temperatures reached to the boiling point for stainless steel and then turned into gaseous vapor.
Boeing, however, was not to be deterred from its celebrated, fuel-efficient “green” Dreamliner, which is loaded with the troublesome batteries. Despite never finding out what caused the Japanese airlines’ fires, the company took measures designed to vent heat and flames outside the fuselage and thus mitigate risk, rather than try to detect the cause of the fires in the first place.
The FAA says the solution is good enough, but that may not instill confidence since the agency certified the airworthiness of the Dreamliner batteries in the first place. A National Transportation Safety Board investigation into the original fires determined that both FAA and Boeing failed to sufficiently oversee the batteries’ manufacturing process, which opened the door to design flaws. The list of failures in the safety inspection process is reportedly lengthy.
The problems haven’t fully dissipated. In January 2014 Japan Air Lines suffered another malfunction with a Dreamliner battery overheating, with reported smoke and liquid coming out. Last month an Aeromexico Dreamliner made an emergency landing in Ireland due to an alert in the cargo hold, but a spokesman said there was no fire. The cause has not yet been announced. And in May the FAA issued a maintenance mandate for the Dreamliner, after testing showed the plane could lose all electrical power after being continuously powered for 248 days.
[Originally posted at NLPC]