Loss of Control Due to Elevator Trim Failure Resulting in Unrecoverable Spin

Casualties unknown • Lily Lake, IL, US

A pilot experienced a complete failure of the elevator trim system during flight maneuvers. Attempts to relieve control surface loads through specific pitch inputs resulted in an aerodynamic stall and subsequent spin from which recovery was not possible before impact.

What happened

The incident began with reports that a neighbor had operated the aircraft earlier in the day, noting difficulties in adjusting the elevator trim while airborne. Prior to the subject flight, the pilot verified the trim system's functionality on the ground; it appeared to operate normally, leading him to set it for cruise configuration before executing a standard takeoff.

During the flight, while maneuvering onto a crosswind leg, the pilot attempted to adjust the elevator trim but found the mechanism unresponsive. In an effort to reduce the aerodynamic load on the stabilizer, he pulled back on the control stick to initiate a climb and then released the pressure to place the aircraft in a near-zero gravity state. The trim remained immovable despite this action.

The pilot attempted another upward pull with increased force. This aggressive input caused the aircraft to exceed its critical angle of attack, resulting in an aerodynamic stall. The aircraft entered a spin from which the pilot was unable to recover before striking the ground.

The investigation

Post-acc examination of the aircraft revealed that the elevator trim tab was locked in a slight nose-down position. However, no pre-impact mechanical malfunction or defect was detected in the control system components. The failure appeared to be an isolated event rather than a result of structural damage or systemic mechanical failure.

Probable cause

The pilot's inability to recover from an aerodynamic stall and spin following a loss of elevator trim control, which occurred during an attempt to relieve stabilizer loads.

Frequently asked questions

What happened in the 1983-08-02 Piper J3C-65 accident near Lily Lake, IL?

A pilot experienced a complete failure of the elevator trim system during flight maneuvers. Attempts to relieve control surface loads through specific pitch inputs resulted in an aerodynamic stall and subsequent spin from which recovery was not possible before impact.

What aircraft was involved and where did it happen?

The accident on 1983-08-02 involved a Piper J3C-65, registration N27020, at Lily Lake, IL.

What was the probable cause of the accident?

The pilot's inability to recover from an aerodynamic stall and spin following a loss of elevator trim control, which occurred during an attempt to relieve stabilizer loads.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X44028. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.

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