Transport Canada has issued an airworthiness directive limiting high-altitude high-power climbs for A220s as it suspects such operations might have contributed to recent in-flight engine shutdown issues.
"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," the AD says.
The directive concerns all A220s in operation worldwide.
According to the AD, all operators of either A220-100s or A220-300s have until November 2, 2019, to change their flight manuals and incorporate a new normal procedure limiting the engines' N1 setting to 94% above the altitude of 29,000 feet. To prevent engine power exceeding this threshold, manuals have to instruct the pilots to turn the autothrottle off above this altitude.
Transport Canada said that investigations into the recent incidents are ongoing. The most recent high-profile case was an in-flight engine shutdown of Swiss' A220-300 HB-JCC (msn 55012), which experienced mid-flight engine problems on the morning of October 15 and had to divert to Paris CDG. The incident prompted a brief grounding of the entire fleet of A220s operated by Swiss. After repairs, the aircraft involved returned to service on October 28, Flightradar24 ASD-B data shows.
