Canada’s Transportation Safety Board has determined that a small lithium ion battery used to power an e-cigarette caused a baggage compartment fire that resulted in a Mayday and subsequent emergency landing in Calgary last summer. The WestJet Boeing 737-700 with 58 people on board had just taken off for Vancouver on June 14 and was climbing through 9,000 feet when a cargo hold fire light came on. The crew hit the fire extinguisher and headed back to Calgary where the plane was met by fire trucks. By then, the fire was out but the potential was obvious.
The batteries were in an outside pocket of a backpack and the bag was loaded with that side down against the fire-resistant liner of the baggage compartment. The TSB determined one of the batteries had a thermal runaway. The subsequent fire consumed much of the outside of the bag and scorched the liner but did not spread to any other bags. WestJet policy is that all e-cigarettes and their batteries have to travel in the cabin and the battery terminals have to be protected. The bag’s owner said he knew the policy but forgot he had two spare batteries and their charger in the backpack. The bag was screened but the batteries weren’t spotted.