CHI00LA010
1999-10-15 · CAMBRIDGE, Minnesota, United States · None · 1 aircraft · Status: Completed
Airport CRG
Current FAA registration · N4621L
- Make / Model
- CESSNA 172G
- Year of manufacture
- 1966 · 33 years old at event
- Engine
- CONT MOTOR 0-300 SER (145 hp)
- Seats / Engines
- 4 seats · 1 engine
- Last airworthiness date
- 19660518
- ADS-B equipped
- Yes — Mode-S A5A38F
Source: FAA Aircraft Registry (releasable master file).
Aircraft involved
Probable cause & findings
the fractured main landing gear due to the improper maintenance by an unknown person(s) and the inadequate annual inspection by an unqualified person.
Factual narrative
On October 15, 1999, at 1650 central daylight time, a Cessna 172G, N4621L, owned and piloted by a commercial pilot, was substantially damaged following a loss of directional control during landing on runway 34 (3,200 feet by 75 feet, asphalt) at Cambridge Municipal Airport, Cambridge, Minnesota. The right main landing gear strut had fractured at a weld attaching the cabin entry step to the strut. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The flight departed from Anoka County Airport, Blaine, Minnesota, at 1445, en route to Cambridge Municipal Airport. The pilot reported the following in a written statement, "...Upon touchdown on runway 34, I heard a loud snapping noise and then felt something hit bottom right side of fuselage and aircraft began to swerve to right side of runway. I immediately pulled throttle and mixture out and applied left brake to try to return to centerline. The aircraft continued to track off runway into a grassy area on east side of runway. The aircraft stopped approximately 25 yards from edge of runway 34 with the right wingtip and right elevator touching the ground. The right main spring steel landing gear was found at edge of runway." Inspection of the right main landing gear by a Federal Aviation Administration Maintenance Inspector revealed that the cabin entry step was welded on the bottom side of the strut. The cabin entry step on the left main landing gear strut was also welded to its strut. According to the FAA Inspector, there was no logbook entry regarding the welding of the cabin entry step. The last annual inspection was not performed by an inspection authorized (IA) airframe and powerplant mechanic. The Cessna Service Manual states the following under section 5-7, Step Bracket Replacement, "The step bracket is secured to the landing gear strut with Conley-Weld, or a similar epoxy base adhesive." The Cessna 172G impacted the runway during landing following a loss of directional control. The right main landing gear strut had fractured at a weld attaching the cabin entry step to the strut. .' Inspection of the right main landing gear revealed that the cabin entry step was welded on the bottom side of the strut. The cabin entry step on the left main landing gear strut was also welded to its strut. There was no logbook entry regarding the welding of the cabin entry step. The last annual inspection was not performed by an inspection authorized (IA) airframe and powerplant mechanic. The Cessna Service Manual states the following under section 5-7, Step Bracket Replacement, 'The step bracket is secured to the landing gear strut with Conley-Weld, or a similar epoxy base adhesive.' Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1999_CHI00LA010.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…