Fire on board airliners is an increasing risk for the future unless mitigations are put in place, warn the US Federal Aviation Administration and UK Civil Aviation Authority.
The agencies have jointly launched a campaign to increase industry awareness of specific risks and countermeasures, releasing an instructional video titled "Maintenance for fire reduction" to accompany the written advice.
Of particular concern in passenger aircraft, says the CAA, is "the threat of fires breaking out in hidden areas of the aircraft, which cabin crew are unable to access and bring under control in-flight. The importance of reducing fire risks was highlighted with the recent significant fire on the Ethiopian Airlines Boeing 787 on the ground at London Heathrow." The CAA adds a warning: "As the film points out, an in-flight fire that is out of control will, on average, lead to flight crew losing control of the aircraft within 15 minutes."
The FAA and CAA are highlighting maintenance procedures as they affect work on aircraft wiring, both at installation and during subsequent in-service inspection or modification. Damage to wiring insulation, they point out, can lead to short-circuiting and sparking, which can ignite the wiring insulation itself. If dust, lint and other contaminants are allowed to gather in hidden spaces, this can ignite and carry the fire into other areas including the thermal/acoustic blanket that lines the aircraft hull behind the cabin wall and ceiling panels. If that also becomes contaminated during maintenance, it can catch fire, the CAA cautions.
This year, there have also been three high-profile incidents in which lithium batteries on board Boeing 787s have been involved in serious overheating or fire events, and since 2011 two 747-400 freighters have been lost with their crews when lithium battery cargoes started fires that rendered the aircraft uncontrollable before the crews could land them.
Recently, in the face of this growing fire risk, the Royal Aeronautical Society gathered a team of international experts to examine the level of risk and what can be done about it. Its report cites lithium batteries as a major component in the risk list, but relates the fire risk to the entire airline fleet, not just 787s.