Lithium-ion batteries caused a fire in a passenger plane’s luggage hold … even though they shouldn’t have been there.

An official report into the blaze on the aircraft operated by budget Canadian airline company WestJet has also published pictures which show the fire’s intensity.

The Transportation Safety Board report reveals that the pilot had just taken off from Calgary in June with 53 passengers on board and immediately turned round and made an emergency landing.

It had reached an elevation of about 3,000 metres — 9,000 feet — when a fire warning light came on.

A report by CBC News reveals that the flight crew remotely discharged a fire extinguishing bottle in the cargo hold, then declared a mayday before turning back to Calgary.

The plane landed about 10 minutes later and was inspected by fire crews. Passengers and crew members were removed from the plane before the cargo doors were opened.

They discovered a bag showing signs of fire damage – and part of the fire-resistant liner of the cargo compartment was also damaged by fire and heat.

The report states: “The fire did not penetrate the cargo liner or aluminium floor structure and was contained to an area of approximately 24 inches by 24 inches. The burned bag was offloaded and segregated.”

The cockpit voice recorder and flight data recorder were sent to a lab in Ottawa, which showed that other than the indicator light, crew members had no other warnings or alarms.

The report states that the passenger whose bag caught fire flew frequently on business and was aware of WestJet's policy against putting lithium-ion in checked luggage but had accidentally left two lithium-ion batteries in his charger in the bag.

It adds: "The passenger inadvertently packed two spare lithium-ion batteries for his e-cigarette in the front pocket of the bag. The pocket also contained a dry herb vaporiser, a portable speaker, and USB cables.

"The passenger arrived at the airport and checked his bag in. He took his e-cigarette and two other lithium-ion batteries into the passenger cabin, as required by WestJet's policy on e-cigarettes.

"The checked bag proceeded through the passenger baggage security screening and was loaded into the aircraft's lower aft baggage compartment while still containing the two spare lithium-ion batteries.

“An investigation concluded that one battery in the charger experienced a thermal runaway and the interior material of the battery was completely burned out. The thermal runaway was likely caused by external damage. The investigation could not determine if the damage occurred before the battery arrived at the airport or during baggage handling.”

* The problem of fires in personal electronic devices such as mobile phones and laptops on passenger planes seems to be growing. One way to tackle such incidents on planes is to use an AvSax fire containment bag which can deal with fires in personal electronic devices and are now carried on aircraft operated by 65 airline companies across the world – including some of the biggest and best-known.

AvSax  – which won the Queen’s Award for Enterprise in 2018 - has been used 28 times to deal with emergencies since the start of 2017.

More than 13,000 AvSax are now carried on aircraft worldwide. Deployment is so effective that extremely expensive diversions to alternate airports are avoided. 

* Written by Andy Hirst at AH! PR