LAX93IA029
1992-11-05 · MEDFORD, Oregon, United States · None · 1 aircraft · Status: Completed
N131AF has since been reassigned. It is now registered to a different aircraft (PILATUS AIRCRAFT LTD PC-12/47E, built 2021), which was not involved in this event.
Aircraft involved
Probable cause & findings
FATIGUE FAILURE OF THE ELEVATOR CONTROL TUBE ROD END BEARING RESULTING IN A LOSS OF ELEVATOR CONTROL.
Factual narrative
DURING CRUISE FLIGHT AT FLIGHT LEVEL 230, THE AIRPLANE SUDDENLY PITCHED UP AND THE AUTOPILOT DISENGAGED. THE PILOT WAS UNABLE TO CONTROL THE AIRPLANE WITH THE CONTROL YOKE. USING POWER AND TRIM CONTROL, HE FINALLY REGAINED CONTROL OF THE AIRPLANE AND MADE AN EMERGENCY LANDING AT SACRAMENTO WITHOUT FURTHER INCIDENT. INVESTIGATION REVEALED THAT THE THREADED PORTION OF THE ROD END BEARING, P/N 49261-02, HAD SEPARATED AT THE POINT WHERE THE THREADS ARE INSERTED INTO THE AFT END OF THE ELEVATOR CONTROL TUBE ASSEMBLY, P/N 40847-07. THE ELEVATOR CONTROL TUBE CONNECTS TO THE ELEVATOR PITCH HORN. METALLURGICAL EXAMINATION SHOWED THAT THE SEPARATION WAS DUE TO A FATIGUE FAILURE. THE AIRCRAFT HAD BEEN INSPECTED AT 37 HRS AND 134 HRS BEFORE THE INCIDENT IN ACCORDANCE WITH AN APPROVED AIRCRAFT INSPECTION PROGRAM. NEITHER INSPECTION SPECIFICALLY ADDRESSED AN INSPECTION OF THE ELEVATOR CONTROL TUBE ASSEMBLY. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1992_LAX93IA029.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
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Related research
Matched on aircraft type or causal vocabulary (autopilot). All research papers
- arXiv 2025 · arXiv preprint ROSflight 2.0: Lean ROS 2-Based Autopilot for Unmanned Aerial Vehicles
ROSflight is a lean, open-source autopilot ecosystem for unmanned aerial vehicles (UAVs). Designed by researchers for researchers, it is built to lower the barrier to entry to UAV research and acceler…
- arXiv 2025 · arXiv preprint ROSplane 2.0: A Fixed-Wing Autopilot for Research
Unmanned aerial vehicle (UAV) research requires the integration of cutting-edge technology into existing autopilot frameworks.
- arXiv 2024 · arXiv preprint A Data-Driven Autopilot for Fixed-Wing Aircraft Based on Model Predictive Control
Autopilots for fixed-wing aircraft are typically designed based on linearized aerodynamic models consisting of stability and control derivatives obtained from wind-tunnel testing.
- arXiv 2022 · arXiv preprint Experimental Flight Testing of a Fault-Tolerant Adaptive Autopilot for Fixed-Wing Aircraft
This paper presents an adaptive autopilot for fixed-wing aircraft and compares its performance with a fixed-gain autopilot.
- arXiv 2021 · arXiv preprint An Adaptive Digital Autopilot for Fixed-Wing Aircraft with Actuator Faults
This paper develops an adaptive digital autopilot for a fixed-wing aircraft and compares its performance with a fixed-gain autopilot.
- arXiv 2026 · arXiv preprint Robust Adaptive Sliding-Mode Control for Damaged Fixed-Wing UAVs
Many unmanned aerial vehicles (UAVs) can remain aerodynamically flyable after sustaining structural or control surface damage, yet insufficient robustness in conventional autopilots often leads to mis…