Users of the Airbus A220 must take into account operational limitations when deploying the aircraft. After a series of incidents with the Pratt & Whitney PW1500G engines of the A220, Transport Canada, relayed by the European Aviation Safety Agency, issued an airworthiness directive which came into effect October 26 and requires to lower the engine power to 94% above an altitude of 29,000 feet (just over 8,800 metres).
In the past, there have been several incidents in which SWISS A220s were confronted with engine failures. In July 2019, a part of one of the engines had separated in flight, over France. On September 16 and October 15, the same type of incidents occurred on flights between Geneva and London. In each case, the aircraft had been forced to make an emergency landing.
SWISS then decided to ground temporarily its 29-strong A220 fleet, with many cancellations as a result. After thorough inspections, the fleet was put back into use after two days. Korean Air also inspected its A220s. These proved to be, according to the companies, in excellent condition. Other companies saw no reason to stop the aircraft.
“Preliminary survey results indicate that high altitude climbs at high thrust levels on engines of some nominal thrust may be a contributing factor,” said Transport Canada in its note.
The airworthiness directive also means that pilots must switch off the autothrottle when climbing above 29,000 feet. If pilots desperately exceed the set limit for more than twenty seconds, this must be reported.
in addition to reducing power, crews will no longer exceed an altitude of 35,000 feet (just over 10,600m) when weather conditions can lead to frost formation.
The airworthiness directive applies to both the A220-100 and the larger A220-300. To date, a total of 82 A220-100s and A220-300s (formerly Bombardier CS100 and CS300) have been delivered. Users include four other companies besides SWISS: airBaltic, Delta Air Lines, Korean Air and Air Tanzania.