# NTSB WPR16LA068: Cessna 140, N3625V, Independence, OR, February 13, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 13, 2016, 09:30 local (17:30 UTC) - Place: Independence, OR - Coordinates: 44.86639, -123.198333 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.8664&lon=-123.1983&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 1, 2017 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA Portland FSDO - NTSB case key (mKey): 92714 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR16LA068 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/92714/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=92714 - Page: https://openairdocs.org/ntsb/WPR16LA068 ## Probable cause The failure of the left main landing gear wheel axle due to a fatigue crack. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: main gear strut/axle/truck](https://openairdocs.org/ntsb-findings/01023213): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Cessna 140, 2 cases](https://openairdocs.org/ntsb-findings/01023213/cases.md?model=2071602), [All aircraft, 86 cases](https://openairdocs.org/ntsb-findings/01023213/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: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Cessna 140, 5 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=2071602), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [Cessna 140, 46 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=2071602), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 140, 32 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2071602), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The private pilot was landing the airplane on a dry, hard-surfaced runway. He stated that the approach and touchdown were normal. Just after touchdown, he felt "something similar to a bump," and the airplane started to drift to the left. He thought that the airplane possibly had a flat tire and tried to compensate with rudder input, but the airplane continued drifting to the left, exited the left side of the runway, and ground looped, resulting in substantial damage to the right wing and fuselage. An on-scene examination revealed that the left main landing gear axle had fractured, resulting in the separation of the wheel assembly. A detailed examination revealed that the axle was fractured near the inboard end, just outboard of the axle attachment flange. Portions of the fracture surface at the upper and lower sides of the axle had relatively smooth features oriented perpendicular to the outer surface, consistent with fatigue. The fatigue cracks initiated at a fillet corner at a change in the axle's outer diameter. The manufacturer specified inspection intervals to check for cracks and corrosion of the main landing gear axle; however, the accident airplane's maintenance logs were not located, and the airplane's maintenance history could not be determined. ## Factual narrative On February 13, 2016, about 0930 Pacific standard time, a Cessna 140G airplane, N3625V, sustained substantial damage when the left main landing gear axle broke during landing and the airplane ground looped at the Independence State Airport, Independence, Oregon. The private pilot and one passenger were not injured. The airplane was owned by the pilot and operated as a personal, cross-country flight under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan had been filed for the flight. In a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge, the pilot stated that the approach and touchdown were normal. Just after touchdown, he felt something similar to a bump, and the airplane started to drift to the left. He stated that he thought that he possibly had a flat tire and tried to compensate, but the airplane continued drifting to the left and exited the left side of the runway into the dirt and ground looped, sustaining substantial damage to the right wing and fuselage. A Federal Aviation Administration inspector from the Portland Flight Standards District Office was at the airport at the time of the accident and examined the airplane at the accident site. The examination revealed that the left main landing gear axle had fractured and the wheel assembly separated from the airplane. A detailed examination of the fractured axle by the NTSB materials laboratory revealed that the axle was fractured near the inboard end just outboard of the axle attachment flange. Portions of the fracture surface at the upper and lower sides of the axle had relatively smooth features oriented perpendicular to the outer surface, features consistent with fatigue. The fatigue cracks initiated at a fillet corner at a change in outer diameter for the axle. According to a representative for Cessna contacted by telephone, inspections of the main landing gear axle should be in accordance with Section 2A of the Maintenance Manual for the 100-series airplanes. The axles should be inspected for cracks and corrosion initially after 10 years or 4,000 hours and then at subsequent intervals of 3 years or 1,000 hours. The inspection consists of removing the wheel and completing a visual inspection. If any crack is suspected, an eddy current inspection is then required. The airplane was manufactured in 1948. The owner/operator reported that the last annual inspection was completed about 7 months prior to the accident at a total airframe time of 6,314.5 hours. No airframe logbooks were located during the investigation, therefore it was not determined when the last inspection of the main landing gear axle occurred. ## Aircraft - Registration: [N3625V](https://openairdocs.org/deregistered/N3625V-2018-05-30), registration cancelled 2018-05-30, S/N 14896, built 1948 (OpenAirDocs) - Reported make and model: CESSNA 140 (G) - Registry model: [Cessna 140](https://openairdocs.org/model/cessna-140) (registry code 2071602) (OpenAirDocs) - Registry engine: [Continental C90 series](https://openairdocs.org/engine/continental-c90-series) (registry code 17009, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 14896 - Year built: 1948 - Airframe hours: 6315 - Engines: CONT MOTOR C90 SERIES 90 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 15, 2015 - Departed: Aurora, OR - Destination: 7S5, Independence, OR - Airport: 7S5, Independence State, runway 16, 3,142 × 60 ft, asphalt - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; seat: left; restraint: lap only; flight hours: 1,360 total, 1,310 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 48 °F, dew point 43 °F - Altimeter: 30.35 inHg - Observed at: KSLE, 9 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 20160213001009A](https://openairdocs.org/incident/20160213001009A), Feb 13, 2016: Cessna 140, Independence, OR, Substantial damage. Pilot reported uneventful approach and landing to rwy 16 at 7S5, but on touchdown noticed aircraft pulled hard to left and was unable to maintain directional… ## Other investigations on N3625V (2) 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 MIA95LA113](https://openairdocs.org/ntsb/MIA95LA113), Apr 14, 1995: Cessna 140 (N3625V), Foxworth, MS, substantial damage. Probable cause: THE PILOT-IN-COMMAND'S SELECTION OF AN UNUITABLE LANDING STRIP FOR LANDING. - [NTSB FTW83LA403](https://openairdocs.org/ntsb/FTW83LA403), Aug 29, 1983: Cessna 140 (N3625V), Hitchcock, TX, substantial damage ## Docket (2 files) The files NTSB released with the investigation on March 30, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=92714. 3.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40450567&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Materials Laboratory Factual Report 16-096 (item 2, .PDF, 4 photos, 609 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40450568&FileExtension=.PDF&FileName=Materials%20Laboratory%20Factual%20Report%2016-096-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.