Investigators are probing another serious engine failure on a Swiss Airbus A220-300, less than two months after a previous similar incident involving a sister aircraft on the same route.

The aircraft (HB-JCA) had been operating Geneva-London Heathrow on 16 September when the failure occurred in the left-hand Pratt & Whitney PW1500G engine during climb.

US National Transportation Safety Board investigators state that the incident took place just before the twinjet reached its cruising altitude of 35,000ft.

The crew returned to Geneva after carrying out quick-reference handbook procedures and declaring an emergency.

Inspection of the aircraft after it landed showed that the stage-one rotor in the low-pressure compressor had separated and there was a hole in the compressor case.

None of the 77 occupants was injured.

French investigators were already looking into the failure of the left-hand PW1500G on another Swiss A220-300, under similar circumstances, on 25 July.

The aircraft (HB-JCM) had departed Geneva for Heathrow and had been climbing through 32,000ft when the failure occurred.

Investigation authority BEA subsequently sought public assistance to find engine components which they believe were shed from the aircraft over France. The stage-one rotor of the low-pressure compressor was found to be missing after the jet diverted to Paris.

The aircraft involved in the latest incident was delivered to Swiss in May 2017. It had been operating the LX358 service while the earlier event occurred to flight LX348.

Investigation of both incidents has been delegated to the US NTSB.