What happened
During the takeoff roll, the flight engineer observed a warning light on the number 3 engine. The aircraft type proceeded through V1 and V2 speeds and rotated successfully. Shortly after liftoff, following the command to retract gear and flaps, a loud noise occurred and the crew confirmed the loss of the number 3 engine. A failure of the number 1 propeller blade caused an immediate imbalance, which resulted in the engine separation from the airframe. The departing blade struck the lower fuselage and damaged the number 2 engine, severing hydraulic, pneumatic, electrical, and emergency airbrake lines.
The crew declared an emergency and attempted to land on runway 07. Although debris was noted at the runway intersection, the pilot continued the approach. Upon landing, the propellers failed to enter reverse pitch, and the aircraft suffered a loss of braking capability. After applying maximum power, the aircraft briefly took off again, clearing the end of the runway by approximately 30 feet. The crew then diverted to Van Nuys Airport, reporting a lack of brakes. During this period, the number 2 engine also failed due to low oil pressure and loss of BMEP indication.
While approaching runway 34L at Van Nuys, the aircraft lost sufficient altitude and airspeed to reach the runway. The crew attempted an emergency landing at the Woodley Municipal Golf Course. The aircraft struck the ground on its main gear, bounced multiple times, and the nose impacted a concrete foundation. The aircraft eventually came to rest against a trailer and ignited approximately 20 minutes later. The accident resulted in 3 fatalities and 3 injuries.
Findings
- The primary cause of the initial engine separation was the failure of a propeller blade on the number 3 engine.
- This failure originated from a fatigue crack located on the leading edge beneath the deicer boot.
- The crack remained undetected because of an improperly performed overhaul.