Canada issues Emergency AD to limit Airbus A220 engine power settings after recent incidents
Regulator Transport Canada issued an Emergency Airworthiness Directive (AD) to limit certain engine power settings on Airbus A220 aircraft following three recent failures.
Three inflight shutdowns occurred within three months: July 25, 2019, September 16, 2019, and October 15, 2019. In each case, the aircraft involved was a Swiss International Air Lines Airbus A220-300 (formerly named Bombardier CSeries 300) with Pratt & Whitney PW1524G-3 engines. These inflight shutdowns were due to failure of the low-pressure compressor (LPC) stage 1 rotor, which resulted in the rotor disk releasing from the LPC case and damaging the engine.
Investigations are ongoing to determine the root cause, but preliminary investigation results indicate high altitude climbs at higher thrust settings for engines with certain thrust ratings may be a contributor. This condition, if not corrected, could lead to an uncontained failure of the engine and damage to the aeroplane.
Transport Canada issued the AD on October 26, introducing a new Aircraft Flight Manual (AFM) limitation and normal procedure to limit the engine N1 setting to 94% while above 29000 feet. This AD is considered an interim action and further AD action may follow.