24/7 Wall St.

At a session later this week of the Montreal meeting of the International Civil Aviation Organization (ICAO), the U.S. Federal Aviation Administration (FAA) is presenting a working paper that recommends a ban on transporting portable electronic devices larger than a mobile phone or tablet in checked luggage.

A ban on carry-on devices was enforced earlier this year on flights from some Middle Eastern countries into the the United States and the United Kingdom. The result was that more laptops were included in checked baggage, with “little research data available on the behavior, effects and risks” of carrying the devices in checked baggage.

In 10 tests conducted by the FAA’s Fire Safety Branch, a heater was placed next to a laptop’s lithium-ion battery to force the battery into “thermal runaway.” The working paper notes:

For the first five tests, the suitcases were filled with clothes, shoes, etc., but no other currently permitted dangerous goods. In four of those tests, the fire was contained and eventually self-extinguished, and the suitcases were not breached. In one test, conducted without the Halon fire suppression system, the resulting fire burned out of the suitcase and fully consumed it; in this test, the battery burned a hole in the suitcase, which may have allowed oxygen to enter to fuel the fire.

Even more dangerous was an aerosol can included in the same piece of luggage as the laptop:

[I]f a [portable electronic device] is packed in a suitcase with an aerosol can and a thermal runaway event occurs, there is the potential for an aerosol can explosion. The explosion itself may or may not be strong enough to structurally damage the aircraft, but in a Class C cargo compartment it will most likely compromise the Halon fire suppression system by dislodging blow panels or cargo liners, rendering the compartment unable to contain the Halon. The fire suppression system of the aircraft is then compromised, which could lead to the loss of the aircraft.

The FAA reviewed several changes that could make carrying laptops in checked luggage safer, but concluded that requiring them to be carried “only in the cabin is the simplest, most effective, and most efficient option for addressing this identified safety risk.”

The full working paper is available at the ICAO website.