CEN21LA256
2021-06-02 · San Angelo, Texas, United States · None · 1 aircraft · Status: Completed
Airport SJT
Aircraft involved
Probable cause & findings
Inadequate maintenance of the left main landing gear strut, which resulted in a landing gear collapse.
Factual narrative
On June 2, 2021, about 2050 central daylight time, a Piper PA-28-161 airplane, N2120J, was substantially damaged when it was involved in an accident near San Angelo, Texas. The flight instructor and student pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The instructor stated that, during the landing roll, he noticed the left wing lower as if the tire was flat. The airplane subsequently veered left, which resulted in substantial damage to the left wing. Postaccident examination revealed a hole on top of the left wing where the left main landing gear strut assembly had broken loose from the upper left wing spar cap. Several mounting holes in the left main landing gear strut were elongated, consistent with wear over an extended period of time. Several landing gear strut mounting bolts were loose, and all bolts were missing from the lower strut assembly mount. During removal of the left main landing gear strut assembly from the left wing, only the brake line remained attached, with no other hardware securing the left main landing gear strut to the left wing. The airplane’s maintenance records were not made available for review, and the maintenance history of the landing gear could not be determined. The flight instructor stated that, during the landing roll, the left main landing gear collapsed, and the airplane veered left, which damaged the left wing. Examination of the left main landing gear strut revealed that several mounting holes were elongated, consistent with wear over an extended period, and several bolts were missing. The landing gear strut’s missing bolts and loose hardware likely resulted in the failure of the remaining fasteners to support the airplane’s weight and resulted in the landing gear collapse. Although the airplane’s maintenance records were not made available for review and the maintenance history of the landing gear could not be determined, the elongated mounting holes and missing bolts were consistent with maintenance personnel’s failure to ensure that proper torque was applied to the landing gear strut hardware. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12
NTSB Findings
FAA avdata. C = Cause, F = Factor.
- — Aircraft-Aircraft systems-Landing gear system-Main landing gear-Inadequate inspection
- — Personnel issues-Task performance-Maintenance-(general)-Maintenance personnel
Verbatim from NTSB's published report. Source file
NTSB_2021_CEN21LA256.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 (maintenance). All research papers
- Embry-Riddle Scholarly Commons 2026 · Journal article (IJAAA) From Reactive to Predictive: A hybrid Trust-Mediated Adoption Framework for Data-Driven Maintenance in Distributed-Authority Aviation Environments
Modern aviation maintenance operates within increasingly data-intensive technological environments, yet the operational integration of predictive maintenance into routine decision-making remains incon…
- Semantic Scholar 2026 · Article (Reliability Engineering & System Safety) Understanding human error in military aviation maintenance: The role of Performance shaping factors, cognitive workload and error orientation
- Semantic Scholar 2025 · Article (Applied Sciences) Decision-Making Framework for Aviation Safety in Predictive Maintenance Strategies
The implementation of predictive maintenance (PM) in aviation presents unique challenges due to strict safety requirements, complex operational environments, and regulatory constraints.
- Semantic Scholar 2024 · Article (Defence Science Journal) Modelling of Human Factors in Aviation Maintenance Using HFACS ME Human Factors Analysis and Classification System Maintenance Extension and Bayesian Network
Aircraft maintenance is a complex task involving a skilled human workforce, spare parts, and various other resources. Human factors are an inherent element of the human workforce.
- Embry-Riddle Scholarly Commons 2024 · Journal article (JAAER) A New Trajectory in UAV Safety: Leveraging Reinforcement Learning for Distance Maintenance Under Wind Variations
In the field of aviation, safety is a critical cornerstone, and the operation of Unmanned Aerial Vehicle (UAV) systems is deeply connected with this principle.
- Embry-Riddle Scholarly Commons 2024 · Journal article (JAAER) Low-Resource Automatic Speech Recognition Domain Adaptation – A Case-Study in Aviation Maintenance
With timeliness and efficiency being critical in the aviation maintenance industry, the need has been growing for smart technological solutions that optimize and streamline the different underlying ta…