The following article first appeared as a Comment in the 30 April 2013 issue of Flight International
Even as Boeing scrambles its technical squads to begin the modification work on the grounded 787 fleet, there is an inescapable sense of unfinished business with the battery fire investigation.
Because the airframer cannot yet be certain that it’s tamed the lithium dragon that crippled two Japanese 787s in January. Its response – a containment system to prevent collateral damage – is functional rather than elegant: effectively a big stick with which to beat the dragon unconscious if it gets out of hand.
But it’s really the only option for the time being. Boeing has conceded that it might never fully understand the failures that led to the grounding, which leaves the company in an uneasy limbo.
The situation is not unprecedented. Investigators probing the explosion that destroyed a TWA 747 over the Atlantic in 1986 concluded that the source of ignition “could not be determined with certainty”. Their best guess – excessive voltage arising from a short circuit – drove the effort to inert fuel tanks and contain the wild and transient nature of wayward electricity.
Neither of the 787 incidents was on the same scale, of course, which is to Boeing’s credit. But the whole saga highlights the dilemma of technological advancement, and the possibility that the extent of knowledge – even that as deep as Boeing’s – can sometimes unexpectedly fall short. The need to hunt for the “unknown unknowns” affecting a new aircraft is a lesson that, in the jet age, dates back to the de Havilland Comet.
While Boeing’s intense round-the-clock effort to construct fault trees, examine the battery’s functioning and test for potential flaws is commendable, it also leaves the company exposed to the obvious question as to why it hadn’t done all that before.
Fear of fire is hard-wired into the human mind. Given the well-documented hazards associated with lithium-ion batteries, and the images of smoke pouring from the hold of the Japan Airlines 787 at Boston, Boeing’s reputation might have fared better if it had demonstrated a little more humility – perhaps even left open the option of reverting to nickel-cadmium.
By enabling the 787 to return to flight relatively quickly, the containment system – with its weight penalty – is less of a best solution than the least unpalatable one. Even if the revamped battery demonstrates itself to be docile, don’t expect any quick restoration of trust in lithium-ion technology until a few more of those unknowns are no longer unknown.