Fatal training accident near Ontario, California

5 fatalities • Ontario, United States of America • Landing (descent or approach)

A training flight involving an engine-out simulation ended in a fatal crash during an approach to runway 25R, resulting in five fatalities.

What happened

During a scheduled training mission traveling from Los Angeles toward Ontario, the crew was performing a specialized procedure designed to simulate an engine failure. The objective of the flight was for the supervised pilot to execute an ILS approach with one engine non-functional, followed by a missed approach and a go-around maneuver.

As the aircraft was on final approach to runway 25R, the plane became uncontrollable and struck a field. The impact resulted in the total destruction of the aircraft and caused the deaths of all five crew members.

Findings

Investigations determined that the accident was triggered by the failure of a support fitting for the rudder hydraulic actuator. This mechanical failure led to an undetected loss of control over the left rudder. Because the flight was being conducted under conditions simulating an engine-out scenario, the loss of directional control prevented the crew from stabilizing the aircraft during the go-around phase. Additionally, environmental factors played a role, as existing weather conditions reduced external visual references, making it difficult for the flight check captain to quickly identify the change in aircraft performance.

Probable cause

The failure of a rudder hydraulic actuator support fitting caused an unobserved loss of left rudder control during a simulated engine-out maneuver.

Frequently asked questions

What happened in the 1971-03-31 Boeing 720 accident near Ontario, United States of America?

A training flight involving an engine-out simulation ended in a fatal crash during an approach to runway 25R, resulting in five fatalities.

Were there any fatalities in the 1971-03-31 Boeing 720 accident?

The accident was fatal, resulting in 5 fatalities.

What aircraft was involved and where did it happen?

The accident on 1971-03-31 involved a Boeing 720, registration N3166, operated by Western Airlines, at Ontario, United States of America.

What was the probable cause of the accident?

The failure of a rudder hydraulic actuator support fitting caused an unobserved loss of left rudder control during a simulated engine-out maneuver.

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