# NTSB WPR17LA037: Beech A23 24, N7998L, Anacortes, WA, December 11, 2016

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 3 · Limited · Final report
- Date: December 11, 2016, 11:57 local (19:57 UTC)
- Place: Anacortes, WA
- Coordinates: 48.498611, -122.662498 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.4986&lon=-122.6625&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Western Pacific Region
- NTSB case key (mKey): 94501
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR17LA037
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94501/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94501
- Page: https://openairdocs.org/ntsb/WPR17LA037

## Probable cause

The pilot's failure to maintain directional control during the landing roll, which resulted in a runway excursion and separation of the left main landing gear.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Beech A23-24, 4 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=1151226), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Beech A23-24, 6 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1151226), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Beech A23-24, 2 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=1151226), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md)
- [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [Beech A23-24, 4 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=1151226), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md)
- [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Beech A23-24, 5 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=1151226), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md)

## Analysis

During the landing roll, the airplane began to swerve to the left and continued off the runway, after which the left main landing gear assembly separated from the airplane. Examination revealed substantial damage to the left wing and horizontal stabilizer. The pilot did not provide a written statement, nor did he complete the NTSB Pilot/Operator Aircraft Accident/Incident Report Form 6120.1; therefore, the pilot's flight experience and the airplane's maintenance history could not be determined. The accident is consistent with the pilot's failure to maintain directional control during the landing roll.

## Factual narrative

On December 11, 2016, about 1157 Pacific standard time, a Beech A23-19, N7998L, was substantially damaged when it was involved in an accident at Anacortes Airport (74S), Anacortes, Washington. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported to a Federal Aviation Administration inspector that, during landing, the airplane began to swerve to the left and continued off the runway, during which the left main landing gear separated. The inspector traveled to the accident site and examined the airplane, which sustained substantial damage to the left wing and horizontal stabilizer. The pilot did not provide a written statement, nor did he complete the NTSB Pilot/Operator Aircraft Accident/Incident Report Form 6120.1; therefore, the pilot's flight experience and the airplane's maintenance history could not be determined.

## Aircraft

- Registration: [N7998L](https://openairdocs.org/aircraft/N7998L), registered now, S/N MA-161, built 1966 (OpenAirDocs)
- Reported make and model: BEECH A23 24 (NO SERIES)
- Registry model: [Beech A23-24](https://openairdocs.org/model/beech-a23-24) (registry code 1151226) (OpenAirDocs)
- Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: MA-161
- Year built: 1966
- Engines: LYCOMING I0360 SER 225 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Utility
- Destination: Same as departure
- Airport: 74S, Anacortes, runway 18/36, 3,015 × 60 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 69; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; seat: left; flight hours: 0 total, 0 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 150° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: 1,400 ft broken
- Temperature: 5 °F, dew point 4 °F
- Altimeter: 29.90 inHg
- Observed at: KBVS, 9.7 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20161211020189A](https://openairdocs.org/incident/20161211020189A), Dec 11, 2016: Beech A23-24, Anacortes, WA, Substantial damage. On December 11, 2016 at approximately 1103 PST, a Beechcraft musketeer, N7998L,[privacy data omitted], landed on runway 36 at Anacortes Airport, WA. This…

## Docket (2 files)

The files NTSB released with the investigation on March 3, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94501. 3.7 MB in all.

- Summary of findings (FAA) (item 1, PDF, 1 page, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11959312&FileExtension=pdf&FileName=Summary%20of%20Findings_Redacted-Rel.pdf
- Photos (FAA) (item 2, PDF, 3 pages, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11958772&FileExtension=pdf&FileName=Photos%20(FAA)-Rel.pdf

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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