The US National Transportation Safety Board (NTSB) is investigating an uncontained engine failure, the first of its kind, on a GE CF34-3B1-powered Bombardier CRJ200LR.

The incident occurred at 17:30 Thursday evening when a Mesa Airlines aircraft as flight 2985 from Denver, Colorado to Phoenix, Arizona shed a fan blade and the forward cowling from its left engine in cruise flight around 50nm (100km) out of Denver international airport, causing the crew to declare an emergency and return to Denver. Mesa Brian Gillman says no evacuation was necessary and the US Federal Aviation Administration reported that there were no injuries among the three crew and 50 passengers.  

Uncontained GE CF34-3B1 on CRJ200 W445

Engine manufacturer GE has sent three representatives to support the NTSB in its investigation, says a spokesman, who added that there are more than 2,000 of the “extremely reliable” engines in service since 1992. GE says failure is the first of its kind for the turbofan engine. Flight's fleet database ACAS shows that the aircraft, N17337, has not been damaged since it was delivered new to Mesa on 22 September 1999.

Bombardier declined from commenting on the incident, saying it would have to wait until the NTSB concludes its investigation.