Cessna 550 N75WL accident near Port Aransas, Texas

Probable cause

An in-flight collision with multiple birds, which resulted in separation of the right engine's fan rotor and subsequent total loss of power of the right engine.

NTSB analysis

The turbofan-powered airplane struck birds after takeoff, resulting in a total loss of power on the right engine. The commercial pilot diverted to another airport, where he landed the airplane uneventfully. Examination of the airplane revealed several locations with bird remains, including within the right engine's fan duct. Examination of the right engine showed that the fan and booster stages were missing from the engine; they were found as a unit near the departure airport. Examination of the airplane revealed substantial damage to the fuselage and right wing from the fan and booster stages.

DNA analysis of the bird remains indicated that they were from redhead ducks, which can weigh between 1.38 and 3.31 lbs each. Damage on two fan blades that were approximately opposite each other indicated that at least two birds struck the fan. Examination of the engine components revealed that all damage was consistent with overload failures resulting from the bird strikes. The engine was certified to withstand the impact of a single 4-lb bird; thus, the ingestion of multiple ducks likely exceeded the engine certification requirements. However, the subsequent engine failure was contained because the fan case and inlet were not penetrated, as designed.

Text from the NTSB. Open the NTSB docket for CEN17LA136 for the full record.