Exploding batteries on planes: Rare and small risk

Computerworld - As the U.S. Department of Transportation proposes stricter rules on the shipments of lithium batteries, a close look at Federal Aviation Administration data finds that in-flight incidents involving batteries have been both rare and, apart from one catastrophe, relatively benign.

Between March 1991 and September 2009, there were a total of 109 incidents globally involving batteries that exploded, caught fire, or emitted smoke, according to FAA data (downloadable as a PDF here) collected over the past two decades and analyzed by Computerworld.

The incidents resulted in 51 injuries and one death. Many came from a single August 1999 disaster, in which one passenger died, 13 suffered critical injuries, and 14 had minor injuries, after a Taiwanese passenger jet exploded upon landing. An investigation determined that gasoline from a leaky canister carried in an overhead passenger bin was ignited by sparks from a nearby 12-volt motorcycle battery.

Excluding that horrific disaster, fewer than two documented injuries per year have been reported, all of them minor and most of them involving loading dock workers, and not passengers or in-flight aircrew. Fifteen incidents in the last two decades were serious enough to warrant a decision to re-route a plane or perform an emergency landing, according to FAA data.

For instance, in 2008, there were nine battery accidents resulting in two minor injuries. To put that figure in perspective, that year 3.3 billion lithium batteries were transported (according to the Washington-based Portable Rechargeable Battery Association) on 77 million flights (according to the Airports Council International), including 56 million passenger and combination passenger/cargo flights.

Based on that data, one's chances of being on the same flight with someone who suffers a minor injury because of a malfunctioning battery was about 1 in 28 million in 2008. In comparison, the one-year odds of dying from a car accident in the U.S. are 1 in 6,584, according to the National Safety Council (download PDF).

Additional analysis using data visualization software provided by Tableau Software Inc. shows the following:

• Four accidents involved laptops (two were Dell laptops, one was an IBM machine).
• Cordless drills and other power tools were the devices most commonly implicated in battery accidents; they were involved in 10% of the accidents (11).
• Flashlights were the second-most common device, involved in five incidents.
• Lithium and lithium-ion batteries were involved in 38% of FAA-documented incidents. Large industrial batteries, which are prohibited in carry-on luggage and are already subject to strict packaging regulations worldwide, were involved in 37% of the incidents.
• Lithium-battery-related incidents were far less common in the U.S. than industrial battery incidents (31% of the total versus 41%), especially compared with the rest of the world (where 60% of the incidents involve lithium batteries and 20% involve industrial batteries). That can't be credited to a ban enacted in 2008 barring fliers from carrying spare lithium-ion batteries in their checked luggage: 54% of the incidents on U.S. airplanes in the past two years have involved lithium batteries, double the rate (27%) between 1991 and 2007, before the ban was enacted.

Click to view interactive charts of the FAA data, which details 109 plane-related battery problems during hundreds of millions of flights over the last two decades.

The FAA data, while incomplete, is significant because of the lack of support it provides for proposed new DOT restrictions on air freight shipments of battery-powered devices and on passengers carrying spare alkaline or nickel-metal-hydride batteries in their checked luggage.

The DOT proposal is an extension of the 2008 FAA ban against lithium batteries in checked luggage.