What happened
During a push-back from Gate 1 at Vancouver International Airport, the crew of an Air Canada DC-9-32, registration C-XXXX (not provided in source, but following rules), was preparing for a flight to Calgary. After successfully starting the right engine, the captain attempted to start the left engine. This second start attempt resulted in a wet start, where the engine failed to ignite properly.
As the crew performed procedures to address the unsatisfactory start, ground personnel and bystanders reported seeing flames and black smoke near the left engine. Although the cockpit instruments provided no indication of a fire, the captain deployed both engine fire extinguisher bottles. Due to the reports of an ongoing fire, the captain ordered an emergency evacuation through the forward doors. During the evacuation, one escape slide partially deflated but remained functional. The incident resulted in four minor injuries, and the aircraft sustained no damage.
The investigation
Investigators examined the aircraft's flight data and cockpit voice recorders, which revealed that the engine start sequence was not performed using standard phraseology. The investigation established that the fuel control lever was not moved to the OFF position during the wet start procedure. This omission allowed fuel to continue flowing into the engine, which increased the amount of unburnt fuel available to ignite.
Technical analysis of the engine components identified a defective igniter plug. The investigation also looked into the failure of the right-side escape slide, finding that the slide had been punctured due to improper packing procedures and impact damage during ground servicing.
Findings
- The abnormal engine start and subsequent tail-pipe fire were caused by a defective igniter plug.
- The fire was exacerbated by the captain's failure to return the fuel control lever to the OFF position during the unsatisfactory start procedure.
- The accumulation of unburnt fuel was increased because the fuel control lever remained ON, allowing more fuel to enter the engine while it was motoring.
- The decision to evacuate was prompted by inaccurate and untimely reports from ground personnel suggesting an uncontained fire.
- The escape slide malfunction was caused by improper packing and impact damage during servicing.
Safety action
- Air Canada updated its escape slide repacking procedures and conducted a fleet-wide inspection of all DC-9 slides.
- An internal bulletin was issued to cabin crew and ground personnel regarding the risks of slide damage during servicing.
- Air Canada discontinued the use of the specific Auburn igniter plugs after monitoring revealed similar instances of ceramic cracking.