Incident · 2013-12-23

What the record says

Event date

2013-12-23

Event type

Incident

Highest injury level

No injuries

Aircraft

BOEING 737 3H4 (N360SW)

Operating rule

Part 121

Operator

SOUTHWEST AIRLINES, CO. Operator named in NTSB report

Operated by (per NTSB report)

SOUTHWEST AIRLINES CO

Probable cause

The initial damage to the fan blades was caused by the ingestion of two mallard ducks that caused one or more fan blades to fracture, striking the fan shroud, as well as other passing fan blades, producing various sized blades fragments that created a cascading effect of collateral impact damage to the other fan blades, the fan case, and the inlet cowl. One large blade fragment was deflected out of the fan containment plane, which pierced and exited the inlet cowl in a benign direction. The engine and airplane met the applicable bird and containment design standards since the engine did not catch on fire, no engine cases exhibited any penetrations, the engine was able to be shutdown normally, and the airplane damage did not impact the safe operation of the airplane or create a hazard to the persons on board.

Flight crew

No flight-crew details recorded in the NTSB accident database for this event.