Guidance on the response to an in-flight battery / PED fire / smoke event is provided within ICAO Doc 9481, Emergency Response Guidance for Aircraft Incidents Involving Dangerous Goods.
In summary, this recommends:
- applying the fire-fighting procedure to knock down any flames
- dousing the device with water or other non-flammable liquid
(aimed at cooling to prevent thermal runaway propagating to adjacent cells)
- leaving the device in its place and monitor for any reignition (approximately 10 to 15 minutes)
- completely submerging the item in water and secure the container
- monitoring the device and the surrounding area for the remainder of the flight
Specifying a period before an item can be moved and be rendered completely safe recognises that a lithium battery may reignite. This is because water tipped onto many PEDs such as laptops or tablets may not reach the battery compartment and in turn, this may be insulated by the surface the PED is sat on, for example a seat back meal tray. On the flight deck, dousing an item with water may be difficult due to confined space and the water could potentially damage other electronic systems.
Since the development of the ICAO guidance, new products designed for use in response to lithium battery thermal runaway events have become available. Products which provide both a cooling and containment capability are typically more aligned to the existing ICAO guidance as when used, they are filled with water or other non-flammable liquid to act as a cooling agent.
After knocking down flames, it could conceivably take just a couple of seconds for a PED to be placed inside a containment bag, allowing it to be moved to a place of safety. Passengers could then return to their seats mitigating potential unrelated safety hazards such as injury in the case of severe turbulence. Equally, the effect on flight crew in carrying out their duties following an event on the flight deck would be minimised.
Accordingly, fire containment bags may be used in response to an in-flight battery / PED event, providing that:
- the operator is satisfied that the manufacturer's product performance claims are legitimate;
- use of the selected product has been included in the safety risk assessment required under AMC2 CAT.GEN.MPA.140(c);
- emergency procedures have been amended to reflect use of the equipment;
and
- the crew dangerous goods training programme(s) has been revised and received re-approval by the CAA.