# NTSB ANC13CA038: Beech A36, N1820L, Port Alsworth, AK, April 15, 2013 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: April 15, 2013, 14:45 local (22:45 UTC) - Place: Port Alsworth, AK - Coordinates: 60.198612, -154.324722 - Nearby events: https://openairdocs.org/map.md?lat=60.1986&lon=-154.3247&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: 4 uninjured - Status: Completed, report August 13, 2013 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA Anchorage FSDO - NTSB case key (mKey): 86724 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC13CA038 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/86724/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=86724 - Page: https://openairdocs.org/ntsb/ANC13CA038 ## Probable cause The failure of the left main landing gear retraction brace assembly, resulting in the collapse of the left main landing gear. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: main landing gear](https://openairdocs.org/ntsb-findings/01023210): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Beech A36, 2 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md?model=1151604), [All aircraft, 241 cases](https://openairdocs.org/ntsb-findings/01023210/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 A36, 12 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=1151604), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Beech A36, 78 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1151604), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot was landing the airplane on a dry, unpaved airstrip, when the left main landing gear retraction brace assembly (PN 35-815125-2) broke, and the left main landing gear collapsed. The airplane sustained substantial damage to the left aileron. The pilot stated that there were no preaccident mechanical anomalies with the airplane. Examination of the airplane's maintenance logbooks revealed no record that the brace assembly had ever been replaced during the airframe's time in service of 19,770 hours. The brace is a on-condition replacement part. ## Factual narrative The pilot was landing the airplane on a dry, unpaved airstrip, when the left main landing gear retraction brace assembly (PN 35-815125-2) broke, and the left main landing gear collapsed. The airplane sustained substantial damage to the left aileron. The pilot stated that there were no preaccident mechanical anomalies with the airplane. Examination of the airplane's maintenance logbooks revealed no record that the brace assembly had ever been replaced during the airframe's time in service of 19,770 hours. The brace is a on-condition replacement part. ## Aircraft - Registration: [N1820L](https://openairdocs.org/aircraft/N1820L), registered now, S/N E-843, built 1976 (OpenAirDocs) - Reported make and model: BEECH A36 - Registry model: [Beech A36](https://openairdocs.org/model/beech-a36) (registry code 1151604) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: E-843 - Airframe hours: 19770 - Engines: CONT MOTOR IO 520 SERIES 285 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Lake Clark Air, INC - Registered owner: Alsworth Glen R - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, April 10, 2013, 20 hours before - Departed: PAMR, Anchorage, AK - Destination: AK51, Port Alsworth, AK - Flight plan: Company VFR - Airport: AK51, Port Alsworth, runway 05, 4,200 × 100 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 32; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review March 15, 2013; seat: left; flight hours: 2,043 total, 510 in this make and model, 183 in the last 90 days, 101 in the last 30 days, 13 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 60° at 10 knots - Visibility: 40 statute miles - Lowest ceiling: none - Temperature: 36 °F, dew point 30 °F - Altimeter: 30.36 inHg - Observed at: PALJ, 1 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 20130415006289A](https://openairdocs.org/incident/20130415006289A), Apr 15, 2013: Beech A36, Port Alsworth, AK, Substantial damage. During landing rollout, the left main landing gear drag brace assembly failed resulting in gear collapse. The aircraft came to a stop with the left wing tip in… ## Other investigations on N1820L (3) 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. - [NTSB ANC21LA027](https://openairdocs.org/ntsb/ANC21LA027), Mar 20, 2021: Beech A36 (N1820L), Port Alsworth, AK, substantial damage. Probable cause: The pilot's misidentification of the airport’s active runway, which resulted in an off runway landing and a collision with a snow berm. Contributing to the accident was the runway’s lack of… - [NTSB ANC01LA010](https://openairdocs.org/ntsb/ANC01LA010), Oct 12, 2000: Beech BE-A36 (N1820L), Nondalton, AK, substantial damage. Probable cause: The pilot's inadvertent retraction of the landing gear during the landing roll. - [NTSB ANC98LA159](https://openairdocs.org/ntsb/ANC98LA159), Sep 26, 1998: Beech A36 (N1820L), New Stuyahok, AK, substantial damage. Probable cause: The pilot's failure to extend the landing gear prior to landing. Factors associated with this accident were the pilot's interference with his normal habit pattern, turbulence, and the crosswind… ## Docket (1 files) The files NTSB released with the investigation on July 24, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=86724. 1.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40392991&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.