Series of Airbus A220 engine failures focus of probe

By Tim Hepher

A probe into a series of engine failures on Airbus’s smallest jet, the A220, is studying if a software change set off unexpected vibrations that damaged fast-moving parts and forced three emergency landings, people familiar with the case said.

The airline Swiss briefly halted its fleet of A220 jets for checks on October 15 after a third flight in as many months was forced to divert with engine damage. Engine maker Pratt & Whitney also expanded checks on similar engines worldwide.

Formerly known as the CSeries, the 110-130-seat A220 was designed by Canada’s Bombardier and was one of the first to adopt the new Pratt & Whitney technology. Bombardier sold the programme to Airbus last year due to heavy losses. Wings and other parts of the plane are made in Belfast.

Investigators are focusing on recent changes in engine software that may have caused parts that compress air inside the engine to be set in a way that caused mechanical resonance or destructive vibrations, two of the people said.

Neither the aircraft nor the engine has been grounded but pilots have been told to avoid certain combinations of thrust settings and altitude to avoid the risk of a new problem until the root cause of the three Swiss engine failures can be found.

A third source said it may take until December to confirm the cause, while other scenarios have also not been ruled out.

Airbus, which was starting a Pacific tour to promote the A220, had no immediate comment on the investigation.

Officials at the US National Transportation Safety Board, or NTSB, which is leading an investigation into the recent failures involving the US-built engine, declined comment.

The European Union Aviation Safety Agency said it was monitoring the situation closely and coordinating with the US Federal Aviation Administration.

The head of Pratt & Whitney parent United Technologies said earlier this week it was working on finding the cause and remained confident in the new fuel-saving engine.

“Clearly, any time you get an issue like this, we’re on top of it. The guys are working through it,” chief executive Greg Hayes told analysts on a conference call.

Nobody was hurt in the three incidents, which all took place while flying over France between London and Geneva. But parts from two of the engines were found on the ground.

Reuters. Additional reporting Irish Examiner