Baggage compartment fire occurred on WestJet flight shortly after departing Calgary International
The aircraft departed from Runway 35L at CYYC at approximately 0639. The captain was the pilot flying, and the first officer was the pilot monitoring.
While the aircraft was climbing through 9000 feet above sea level, at 0641:10, a lower aft cargo fire warning light illuminated.
The flight crew immediately followed the CARGO FIRE procedures published in the company's 737NG Quick Reference Handbook (QRH). The CARGO FIRE DISCH switch was activated, and 1 cargo fire extinguishing bottle was discharged.
At 0646, the flight crew declared a MAYDAY emergency and initiated a return to CYYC. Ten minutes later, the aircraft landed on Runway 35R at CYYC and exited onto Taxiway Delta.
After clearing the active runway, the aircraft stopped on the taxiway and was inspected by airport rescue and firefighting (ARFF) services. No visual signs of fire were noted, and no hot spots were detected by infrared camera imaging.
In accordance with the QRH, the flight crew informed ground personnel not to open any cargo doors until all passengers and crew had exited the aircraft.
The aircraft was cleared to taxi back to the gate, where the passengers and crew were deplaned. After all passengers were off the aircraft, ARFF and WestJet ground handling personnel opened the lower aft baggage compartment.
One passenger bag, found face-down near the cargo compartment door opening, showed signs of fire damage.
The fire damage was isolated to the individual bag. Minor thermal damage was found to the cargo compartment's fire-resistant liner near the bag.
The fire did not penetrate the cargo liner or aluminum floor structure and was contained to an area of approximately 24 inches by 24 inches. There was no additional damage to any of the surrounding bags. The burnt bag was offloaded and segregated, and then all other passenger baggage were offloaded.
As per regulations, the aircraft was equipped with a cockpit voice recorder and a flight data recorder, which were removed and sent to the TSB Engineering Laboratory in Ottawa, Ontario.
The data indicated that, other than the lower aft cargo fire warning, the crew did not receive any additional warnings or alarms. The crew's actions were carried out in accordance with the QRH and company standard operating procedures.
Records indicate that the aircraft was certified, equipped, and maintained in accordance with existing regulations and approved procedures.
The Boeing 737-700 (also referred to as 737-7CT) was manufactured by Boeing Commercial Airplanes in 2011. It is a twin-engine, medium-range, turbofan airliner with 140 passenger seats and a cruise speed of about 430 knots.
The passenger whose bag caught fire flew frequently for business purposes and was aware of WestJet's policies with respect to restricted items in checked baggage.
The passenger packed his bag, a tactical-style nylon backpack, on the evening of 13 June 2018 and inadvertently packed 2 spare lithium-ion batteries for his e-cigarette, in the charger, in the front pocket of the bag. The pocket also contained a dry herb vaporizer, a portable speaker, and USB cables.
On the morning of 14 June 2018, the passenger arrived at the airport and checked his bag in. He took his e-cigarette and 2 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 2 spare lithium-ion batteries. ■