What happened
An Air Canada Airbus A320-211, registered as C-FTJO, was operating a flight from Montréal/Pierre Elliot Trudeau International Airport to Toronto/Lester B. Pearson International Airport with 98 passengers and 6 crew members. During the climb, the flight crew noticed an unusual odour in the cabin. Shortly after, the aircraft's monitoring system alerted the crew to a low fluid level in the green hydraulic system. To manage the loss of pressure, the crew de-energized the green hydraulic system, which rendered several components inoperative, including nose wheel steering and normal braking.
The aircraft landed safely at Toronto/Lester B. Pearson International Airport. While stopped on the runway awaiting a tow, the crew re-energized the green hydraulic system to close the landing gear doors at the request of the tow operator. This action immediately caused smoke to enter the cockpit and cabin. The captain ordered an evacuation, and passengers exited via the emergency slides. During the process, 2 passengers and 2 crew members sustained minor injuries.
The investigation
The investigation focused on the source of the smoke and the circumstances of the evacuation. Investigators found that a leak had developed in the number 1 yaw damper due to degraded piston rod seals. This leak allowed hydraulic fluid to flow down the fuselage and into the auxiliary power unit (APU) intake. The APU heated the fluid, which was then distributed through the air conditioning system into the cabin.
While the aircraft had been flagged for monitoring due to a previous fluid loss, the specific modification to address the faulty seals had not been performed on C-FTU. Additionally, investigators examined the evacuation process, noting that several passengers attempted to exit with carry-on luggage, which could potentially obstruct exits or delay egress.
Findings
- A leak from the number 1 yaw damper caused hydraulic fluid to be ingested into the APU, resulting in smoke entering the cabin.
- The evacuation resulted in minor injuries to 4 individuals.
- The presence of carry-on baggage during the evacuation presented a risk of blocking exits and increasing evacuation time.