Investigators probing the Feb. 13 inflight shutdown of the No. 2 Pratt & Whitney PW4077 engine on United Airlines Boeing 777-200 heading to Honolulu have traced the issue to a fan-blade separation, a preliminary NTSB report revealed.

The aircraft, carrying registration N773UA and operating as Flight 1175 en route to Honolulu’s Daniel K. Inouye International Airport (HNL) from San Francisco International (SFO), was descending through 32,700 ft. when “the flight crew received warnings of an engine compressor stall, and shut down the engine,” NTSB said. 

The crew declared an emergency and proceeded to HNL, landing without incident and proceeding to a gate. All 363 passengers and 10 crew members “deplaned normally,” United said in a post-incident statement.

The aircraft suffered minor damage, including loss of its No. 2 engine inlet and fan cowls. 

FlightAware data indicate the aircraft did not leave HNL until March 5, when it performed two flights. The first was a 98-min. sortie that started and ended at HNL—suggesting a post-maintenance check flight. The aircraft then returned to SFO, apparently on another non-revenue flight.

Sean Broderick