ANC21LA086
2021-09-12 · Port Alsworth, Alaska, United States · None · 1 aircraft · Status: Completed
Airport PVT
Current FAA registration · N6476M
- Make / Model
- STINSON 108-3
- Year of manufacture
- 1948 · 73 years old at event
- Engine
- FRANKLIN 6A4165 SERIES (165 hp)
- Seats / Engines
- 4 seats · 1 engine
- Last airworthiness date
- 19580709
- ADS-B equipped
- Yes — Mode-S A88272
Source: FAA Aircraft Registry (releasable master file).
Aircraft involved
Probable cause & findings
A loss of directional control for reasons that could not be determined based on the available information.
Factual narrative
On September 12, 2021, about 0900 Alaska daylight time, a Stinson 108-3, N6476M, was substantially damaged when it was involved in an accident near Port Alsworth, Alaska. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, during the landing roll while applying the brakes, the right brake “went flat.” The airplane veered to the left, impacted a stump, and nosed over, resulting in substantial damage to the fuselage and left wing. A postaccident examination revealed no mechanical anomalies with the brake system that would have precluded normal operation. The pilot reported that, during the landing roll while applying the brakes, the right brake “went flat.” The airplane veered to the left, impacted a stump, and nosed over, resulting in substantial damage to the fuselage and left wing. A postaccident examination revealed no mechanical anomalies with the brake system that would have precluded normal operation. Based on the available information, the reason for the loss of control during landing could not be determined. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12
NTSB Findings
FAA avdata. C = Cause, F = Factor.
- — Aircraft-Aircraft systems-Landing gear system-Brake-Failure
Verbatim from NTSB's published report. Source file
NTSB_2021_ANC21LA086.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
Search this event elsewhere
External sources are reported, not agency: signal that something happened, not fact about what happened.
- TallyAero Live Wire Aviation press
- NTSB CAROL Agency ↗
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Related research
Matched on aircraft type or causal vocabulary (loss of control). All research papers
- 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 …
- NTSB Aircraft Accident Reports 2022 · Accident report Loss of Control on Takeoff in Icing Conditions — Citation 560XL
Cessna Citation 560XL fatal takeoff icing accident, March 2018. Investigation of a Citation 560XL loss-of-control takeoff accident in icing conditions.
- Semantic Scholar 2021 · Article (Aviation) ANALYSIS OF GENERAL AVIATION FIXED-WING AIRCRAFT ACCIDENTS INVOLVING INFLIGHT LOSS OF CONTROL USING A STATE-BASED APPROACH
Inflight loss of control (LOC-I) is a significant cause of General Aviation (GA) fixed-wing aircraft accidents. The United States National Transportation Safety Board’s database provides a rich source…
- NASA NTRS 2021 · Presentation Use of Design of Experiments in Determining Neural Network Architectures for Loss of Control Detection
Abstract—We describe empirical methods for selecting a neural network architecture to implement belief state inference on generic commercial transport aircraft.