Fairchild SA227 AC N2691W accident near Rifle, Colorado

Probable cause

The uncontained engine failure due to the fatigue failure of the second-stage turbine rotor disk.

NTSB analysis

The commercial pilot departed in the twin-engine airplane for a scheduled, domestic cargo flight. He reported that, during the climb, he heard a "bang," which was followed by a loss of engine power and fire indications from the right engine. The pilot declared an emergency and diverted to another airport for an instrument approach and landed uneventfully.

Postaccident examination of the airplane revealed that the right engine's second-stage turbine rotor had separated. One portion of the rotor exited through the left side of the engine and nacelle structure, penetrated the right side of the fuselage, and came to rest inside the fuselage wall. Other portions of the separated rotor exited through the right side of the engine. The engine and the inside of the nacelle structure exhibited fire damage, but no evidence of a sustained fire was found in that area. The examination of the turbine engine revealed fatigue cracks on the second-stage rotor disk, which indicates that the rotor disk likely failed due to fatigue, and this likely resulted in the uncontained engine failure.

Text from the NTSB. Open the NTSB docket for CEN15LA202 for the full record.