Incident Sequence
A charter flight arrived and deplaned without any incident, and there was no indication of smoke, fumes, or heat. Company maintenance personnel subsequently placed damaged passenger seatbacks, which incorporated solid-state chemical oxygen generators, into the forward cargo compartment along with seat covers and oil.
Maintenance Actions
A company mechanic examined the seatbacks to locate a serviceable unit. During this process, he found a loose oxygen canister and handled it improperly by grasping its oxygen hose. The source notes that such handling can release the firing pin, fire the percussion cap, trigger a chemical reaction, and generate oxygen. This reaction can produce up to 430 degrees of heat outside the canister.
Fire Propagation
A fire started in the forward cargo compartment in the vicinity where an oxygen canister was later found with a dented striker plate. The seat covers ignited, and the fire burned through the cabin floor. Subsequently, the fire spread throughout the entire cabin.
Personnel Knowledge
Company maintenance personnel did not know that oxygen generators carried as company supplies were hazardous materials. Additionally, the mechanic was not familiar with the repair or installation of the passenger supplemental oxygen equipment.