# NTSB WPR11LA427: Stinson V77, N9112H, Tillamook, OR, September 3, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 3, 2011, 11:40 local (18:40 UTC) - Place: Tillamook, OR - Coordinates: 45.417499, -123.811668 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.4175&lon=-123.8117&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi-to runway: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report November 26, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA FSDO - NTSB case key (mKey): 81687 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11LA427 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81687/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81687 - Page: https://openairdocs.org/ntsb/WPR11LA427 ## Probable cause The pilot’s loss of directional control while taxiing in a gusting tailwind. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Stinson VULTEE V-77, 1 case](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=8631802), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Stinson VULTEE V-77, 2 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=8631802), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Stinson VULTEE V-77, 1 case](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=8631802), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Stinson VULTEE V-77, 2 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=8631802), [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. - [Taxi-to runway: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [Stinson VULTEE V-77, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=8631802), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Taxi-to runway: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Stinson VULTEE V-77, 1 case](https://openairdocs.org/ntsb-events/094/sequence.md?model=8631802), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The pilot was taxiing for takeoff in a gusting left-quartering tailwind. Suddenly, the airplane rotated over 90 degrees to the left. The right main landing gear collapsed, and the airplane dropped onto its right wing and horizontal stabilizer. The pilot reported that he believed the loss of control was due to a strong gust of wind. Although postaccident visual examination of the airplane revealed some areas of corrosion on the fractured right main landing gear pivot bushing, a follow up laboratory examination determined that the pivot bushing failed due to overload. No evidence of preexisting fatigue cracking was found. ## Factual narrative On September 3, 2011, about 1140 Pacific daylight time, a Stinson V77, N9112H, sustained substantial damage when its right main landing gear collapsed following a loss of control during taxi for takeoff at Tillamook Airport (TMK), Tillamook, Oregon. The airline transport pilot and two passengers were not injured. Tillamook Air Tours was operating the airplane under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the local sight seeing flight. A company flight plan was on file. The pilot stated that he was taxiing on runway 19 with the intent to turn around and take off on runway 01. The wind was a left quartering tailwind, and the first 800 to 1,000 feet of the taxi was uneventful. Suddenly, the airplane rotated over 90 degrees to the left. The right main landing gear collapsed, and the airplane dropped onto its right wing and horizontal stabilizer. The pilot reported that he believed the loss of control was due to a strong gust of wind. Post accident examination of the airplane by a Federal Aviation Administration inspector revealed that the right wing and the horizontal stabilizer were bent, and the fuselage was wrinkled and bent on the left aft lower side and on the right side where the main landing gear joined the fuselage. Additionally, the inspector noted that the right main landing gear pivot bushing, which was made of steel tubing, had cracked longitudinally and split in half, allowing the landing gear leg to separate from the airplane. The inspector noted that some areas of corrosion were present on the landing gear pivot bushing. Pieces of the fractured right main landing gear pivot bushing were examined at the National Transportation Safety Board's Materials Laboratory. The examination found that the fracture features present on the pieces were consistent with overstress fracture. No evidence of preexisting fatigue cracking was found. At 1135, the reported wind at TMK was from 050 at 13 knots. At 1155, the reported wind at TMK was from 050 at 13 knots with gusts to 18 knots. ## Aircraft - Registration: [N9112H](https://openairdocs.org/aircraft/N9112H), registered now, S/N 77-311 (OpenAirDocs) - Reported make and model: STINSON V77 - Registry model: [Stinson VULTEE V-77](https://openairdocs.org/model/stinson-vultee-v-77) (registry code 8631802) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane - Serial number: 77-311 - Airframe hours: 1440 - Engines: Lycoming UNKNOWN ENG 300 horsepower reciprocating - Damage: Substantial damage - Flight: Other work use, Part 91 - Operator: Bowdon Noreen, doing business as Tillamook Air Tours - Registered owner: Bowdon Noreen - Airworthiness certificate: Standard, Normal - Departed: TMK, Tillamook, OR - Destination: TMK, Tillamook, OR - Flight plan: Company VFR - Airport: TMK, Tillamook, runway 01, 2,910 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; flight instructor, airline transport, commercial; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 2, with waivers/limitations; last flight review May 20, 2011; seat: left; flight hours: 6,554 total, 14 in this make and model, 62 in the last 90 days, 27 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 50° at 13 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 36 °F - Altimeter: 29.98 inHg - Observed at: TMK ## 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 20110903019609A](https://openairdocs.org/incident/20110903019609A), Sep 3, 2011: Stinson V77, Tillamook, OR, Substantial damage. Pilot was back taxiing on rwy 19 for a departure on rwy 01 when a gust of wind from east (080) at approx 15KTS hit tail from left rear. Aircraft spun around… ## Docket (7 files) The files NTSB released with the investigation on August 24, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81687. 6.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 676 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375374&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Materials Lab Report (item 2, .PDF, 41 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375375&FileExtension=.PDF&FileName=Materials%20Lab%20Report-Redacted.PDF - Service Difficulty Report (item 3, .PDF, 13 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375376&FileExtension=.PDF&FileName=Service%20Difficulty%20Report-Master.PDF - Photo 1. Right landing gear with structure failure (item 4, .PDF, 204 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375381&FileExtension=.PDF&FileName=Photo%201.%20Right%20landing%20gear%20with%20structure%20failure-Master.PDF - Photo 2. Landing gear structure failure (item 5, .PDF, 201 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375380&FileExtension=.PDF&FileName=Photo%202.%20Landing%20gear%20structure%20failure-Master.PDF - Photo 3. Airframe failure with corrosion (item 6, .PDF, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375383&FileExtension=.PDF&FileName=Photo%203.%20Airframe%20failure%20with%20corrosion-Master.PDF - Photo 4. Airframe failure with corrosion (item 7, .PDF, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375389&FileExtension=.PDF&FileName=Photo%204.%20Airframe%20failure%20with%20corrosion-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.