WPR10CA398
2010-08-04 · Lincoln, California, United States · Serious · 1 aircraft · Status: Completed
Airport LHM
Aircraft involved
Probable cause & findings
A loss of control due to the mechanical disconnection of an aileron pushrod from its bellcrank as a result of the mechanic's failure to properly secure the pushrod attach hardware. Also causal was the pilot's inadequate preflight inspection.
Factual narrative
The student pilot/owner reported that he had about 329 total hours of flight experience, including 250 hours in single-engine airplanes, 58 hours in ultralight aircraft, and 21 hours in gliders. He stated that the accident aircraft was a modified version of the Kolb Firefly ultralight. The single-seat aircraft was registered with the Federal Aviation Administration (FAA) as an experimental amateur-built "Buzzard 1 Motorglider." A week before the accident, the aircraft was assembled by a certificated aircraft mechanic. The pilot reported that he had previously flown the aircraft one time, for about 30 minutes. During the accident flight takeoff roll, the pilot noticed that the aircraft did not "feel right," but he opted to continue. About 250 feet above the ground, the outboard right wing "started to flutter in a violent way," and in response, the pilot reduced engine power and aircraft speed. He then "lost all control." The aircraft impacted the ground in a field, and seriously injured the pilot. About 1 hour after the accident, skydivers noticed the wreckage, and summoned emergency services to rescue the pilot. Examination of the wreckage by an FAA inspector revealed that the bolt that was supposed to attach an aileron pushrod to the outboard aileron bellcrank was lying loose in the bottom of the wing bay; neither the nut nor the cotter pin was recovered. Examination of the opposite aileron bellcrank revealed that the corresponding bolt and nut were not secured by a cotter pin, despite provisions for one. The mechanic who assembled the aircraft stated that he did not install cotter pins in either of the two noted bolts. The pilot stated that he did not inspect the aircraft after assembly, or before the flight. The single-seat aircraft was registered with the Federal Aviation Administration (FAA) as an experimental, amateur-built aircraft. A week before the accident, the aircraft was assembled by a certificated aircraft mechanic. The pilot reported that he had previously flown the aircraft one time, for about 30 minutes. During the accident flight's takeoff roll, the pilot noticed that the aircraft did not "feel right," but he opted to continue. About 250 feet above the ground the outboard right wing "started to flutter in a violent way" and in response the pilot reduced engine power and aircraft speed. He then "lost all control." The aircraft impacted the ground in a field and seriously injured the pilot. About an hour after the accident skydivers noticed the wreckage and summoned emergency services to rescue the pilot. Examination of the wreckage by an FAA inspector revealed that the bolt that was supposed to attach an aileron pushrod to the outboard aileron bellcrank was lying loose in the bottom of the wing bay; neither the nut nor the cotter pin was recovered. Examination of the opposite aileron bellcrank revealed that the corresponding bolt and nut were not secured by a cotter pin, despite provisions for one. The mechanic who assembled the aircraft stated that he did not install cotter pins in either of the two noted bolts. The pilot stated that he did not inspect the aircraft after assembly or before the flight. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12
NTSB Findings
FAA avdata. C = Cause, F = Factor.
- C Aircraft-Aircraft systems-Flight control system-Aileron control system-Incorrect service/maintenance - C
- C Personnel issues-Task performance-Maintenance-Fabrication-Maintenance personnel - C
- C Personnel issues-Task performance-Inspection-Preflight inspection-Pilot - C
- C Aircraft-Aircraft oper/perf/capability-Performance/control parameters-(general)-Attain/maintain not possible - C
Verbatim from NTSB's published report. Source file
NTSB_2010_WPR10CA398.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 (stall, loss of control). All research papers
- Semantic Scholar 2016 · Article (Interacción) Trajectory Recovery System: Angle of Attack Guidance for Inflight Loss of Control
This paper describes the design and development of an ecological display to aid pilots in the recovery of an In-Flight Loss of Control event due to a Stall (ILOC-S).
- NTSB Aircraft Accident Reports 2010 · Accident report Loss of Control on Approach — Colgan Air Flight 3407
Colgan Air 3407 / Continental Connection (Q400) Buffalo NY, February 12, 2009 — 50 fatalities. Definitive investigation of the Colgan 3407 stall-stick-pusher crash on approach to Buffalo.
- NASA NTRS 2026 · Conference Paper Computational Analysis of Steady State Aerodynamics of Transonic Truss-Braced Wing Configuration in Deep Stall
This study presents a computational investigation of steady state aerodynamics of the Subsonic Ultra-Green Aircraft Research (SUGAR) Transonic Truss-Braced Wing (TTBW) configuration over a wide range …
- Embry-Riddle Scholarly Commons 2025 · Journal article (JAAER) A Scoping Review of Aviation Loss of Control Inflight Research
Loss of control – inflight (LOC-I) contributes to aircraft accidents at unacceptably high rates. Significant industry efforts and research have aimed to improve LOC-I prevention, detection, and recove…
- SKYbrary (Eurocontrol) 2024 · SKYbrary article Loss of Control In-Flight (LOC-I) — SKYbrary Knowledge Base
SKYbrary comprehensive knowledge-base entry on Loss of Control In-Flight — definitions, contributing factors, accident case studies (Air France 447, Colgan 3407), and prevention strategies.
- Semantic Scholar 2024 · Article (International Conference on Networking and Services) Risk Assessment of Loss of Control In-Flight Trajectories for Urban Air Mobility Safety
In Urban Air Mobility (UAM), maintaining a minimum separation between aircraft is a safety requirement, which becomes challenging amidst congested air traffic and off-nominal conditions, such as Loss …