NTSB: Southwest Engine Lost A Fan Blade


Jeremy Martin via Airlive and WSJ

The engine that came apart at altitude on a Southwest B737 last month lost one of its fan blades during the flight, the NTSB reported in an investigative update on Monday. The jet was en route from New Orleans to Orlando, Florida, when the incident occurred, and the crew diverted to Pensacola. They landed safely and nobody was hurt. Initial examination of the engine by NTSB investigators found that one fan blade had separated from the fan disk and the root of the separated fan blade remained in the fan hub; however, the remainder of the blade was not recovered. Initial findings from the NTSB’s metallurgical examination include that the fracture surface of the missing blade showed curving crack arrest lines consistent with fatigue crack growth.

The fatigue crack region was 1.14 inches long and 0.217 inches deep. Also, the left engine inlet separated from the engine during the flight, the NTSB said. Debris from the inlet damaged the wing and empennage, and left a 5-inch-by-16-inch hole in the fuselage just above the left wing. No debris from the engine was found in the hole, and the passenger compartment was not penetrated. The cabin did experience depressurization during the incident. The jet engine was made by CFM International, a joint venture between General Electric and Safran. The NTSB investigation is continuing.