# NTSB CEN19LA322: Cessna 195A, N9895A, Pocahontas, IA, September 6, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: September 6, 2019, 12:30 local (17:30 UTC) - Place: Pocahontas, IA - Coordinates: 42.742778, -94.647224 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.7428&lon=-94.6472&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration; Des Moines FSDO - NTSB case key (mKey): 100268 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19LA322 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100268/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100268 - Page: https://openairdocs.org/ntsb/CEN19LA322 ## Probable cause Overload failure of the left main landing gear during landing, which resulted in a loss of directional control. ## 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 · Attain/maintain not possible (probable cause); cases with it: [Cessna 195A, 11 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=2073110), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Landing gear system: main gear strut/axle/truck](https://openairdocs.org/ntsb-findings/01023213): Aircraft › Aircraft systems · Capability exceeded (probable cause); cases with it: [Cessna 195A, 1 case](https://openairdocs.org/ntsb-findings/01023213/cases.md?model=2073110), [All aircraft, 86 cases](https://openairdocs.org/ntsb-findings/01023213/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 195A, 13 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2073110), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Landing gear system: main gear strut/axle/truck](https://openairdocs.org/ntsb-findings/01023213): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Cessna 195A, 1 case](https://openairdocs.org/ntsb-findings/01023213/cases.md?model=2073110), [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: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) (defining event); cases with it: [Cessna 195A, 1 case](https://openairdocs.org/ntsb-events/338/sequence.md?model=2073110), [All aircraft, 563 cases](https://openairdocs.org/ntsb-events/338/sequence.md) - [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [Cessna 195A, 12 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=2073110), [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: [Cessna 195A, 6 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=2073110), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis The airline transport pilot reported that, upon landing, he immediately felt a shift to the left. The left main landing gear fractured and collapsed, and the airplane went off the runway. Postaccident metallurgical examination of the landing gear revealed that the fracture occurred from a thumbnail-shaped fatigue crack in the gear spring strut with multiple origins near the inboard attachment location at the forward edge of its upper surface. Final overstress fracture propagation direction was consistent with a downward-and-aft bending failure mode; thus, the fracture was more likely due to overload rather than the fatigue crack. This was consistent with drag loading of the left main landing gear wheel in combination with side-loading of the outboard side of the left main landing gear wheel, such as that encountered during a crosswind landing, ground loop, and/or hard left turn event. The loads experienced by the landing gear during the accident landing could not be determined, and a structural analysis was not performed to determine if the loads exceeded design load limitations. ## Factual narrative On September 6, 2019, at 1230 central daylight time, a Cessna 195A airplane, N9895A, impacted terrain after it veered off runway 30 at Pocahontas Municipal Airport (POH), Pocahontas, Iowa. The airplane sustained substantial damage. The airline transport pilot and a passenger were uninjured. The airplane was registered to and operated by the pilot under Title 14 Code of Federal Regulations Part 91 as a personal flight that was not operating on a flight plan. Day visual meteorological conditions prevailed at the time of the accident. The flight originated from Bismarck Municipal Airport (BIS), Bismarck, North Dakota, and was destined to POH. The pilot stated the wind was from the north and he determined that runway 30 was an appropriate runway to land on. He stated that during the landing touchdown, he immediately felt a shift to the left. The left main landing gear separated and collapsed, and the airplane went off the runway. The airplane came to a stop with only the tail remaining on the runway. The airplane sustained substantial damage that included wrinkling and upward bending of the left wing. The fractured left main landing gear spring strut was fractured through and shipped to the National Transportation Safety Board Materials Laboratory for examination. The spring strut fractured at approximately 7 inches from the inboard edge at the forward side and approximately 6 inches from the inboard edge at the aft side. A light gray paint coating appeared over the entire part surface and a darker gray paint coating was only present on the outboard piece with a clearly delineated inboard boundary. Both gray coatings were chipped and absent from numerous locations over the part surface thereby exposing areas of the underlying light gray coating as well as areas of brownish-red oxidized metal. A visibly distinct band of brighter light-gray coating and exposed oxidized metal was apparent on the upper and lower surfaces of the spring strut on both sides of the fracture as indicated between the white dashed lines. The upper surface of the spring strut was visibly smoother than the lower surface, which exhibited a dimpled texture. The mating outboard fracture surface of the strut exhibited significant post-fracture mechanical damage and oxidation which obscured some of the finer fracture details. The fracture origin was located on the upper surface at the forward edge of the spring strut. Chevron marks radiated outward from this location along the upper surface and toward the lower surface consistent with an aft and downward crack propagation direction. Closer examination of the origin area revealed a small discolored thumbnail shaped crack and ratchet mark features which were consistent with fatigue cracking from multiple origins. The upper surface of the spring strut adjacent to the thumbnail shaped crack at the fracture origin was absent of gray coating and had exposed oxidized metal over an area approximately 1 inch inboard of the fracture surfaceand approximately 0.75 inch aft of the forward edge. This area was pitted and rougher than the surrounding upper surface where gray coating was intact. Reddish-orange staining was also observed near the fracture origin on the surrounding gray coating. The thumbnail shaped pre-existing crack region was relatively flat and smooth compared to the rest of the fracture surface. Crack arrest lines were evident progressing from at least three origins separated by two visible ratchet marks. Smaller, semi-elliptical sections bounded by crack arrest lines within the thumbnail crack were brownish-red in color, and progressively lighter in color away from the origins. The pre-existing crack measured approximately 0.131 inch along the upper surface of the spring strut and extended approximately 0.058 inch into the part. The fracture surface morphology outside of the thumbnail shaped pre-existing crack was dull and rough in appearance, consistent with overstress separation. The loads experienced by the landing gear during the accident landing are unknown, and a structural analysis was not performed to determine if the loads exceeded design load limits. ## Aircraft - Registration: [N9895A](https://openairdocs.org/deregistered/N9895A-2021-06-26), registration cancelled 2021-06-26, S/N 7598, built 1950 (OpenAirDocs) - Reported make and model: Cessna 195A - Registry model: [Cessna 195A](https://openairdocs.org/model/cessna-195a) (registry code 2073110) (OpenAirDocs) - Registry engine: [Jacobs R755A series](https://openairdocs.org/engine/jacobs-r755a-series) (registry code 35006, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 7598 - Year built: 1950 - Airframe hours: 4186.3 - Engines: Jacobs R755A SERIES 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Pilot - Registered owner: Pilot - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 1, 2019 - Departed: BIS, Bismark, ND - Destination: POH, Pocahontas, IA - Airport: POH, Pocahontas Municipal Airport, runway 30, 4,100 × 60 ft, asphalt - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: none; flight engineer, airline transport; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review June 13, 2019; seat: left; restraint: 3-point; flight hours: 24,800 total, 1,155 in this make and model, 200 in the last 90 days, 70 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 61 °F - Altimeter: 30.15 inHg - Observed at: FOD, 25 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 20190906016909A](https://openairdocs.org/incident/20190906016909A), Sep 6, 2019: Cessna 195A, Pocahontas, IA, Substantial damage. The des moines FSDO was notified of an aircraft accident in Pocahontas, IA on September 6, 2019, by the regional operations center. The aircraft was… ## Docket (2 files) The files NTSB released with the investigation on October 17, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100268. 2.7 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11366404&FileExtension=pdf&FileName=NTSB%20Form%206120%20Master_Redacted-Rel.pdf - 20-024 Materials lab factual report (CEN19LA322) (item 2, PDF, 5 pages, 3 photos, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11212723&FileExtension=pdf&FileName=20-024%20Materials%20Lab%20Factual%20Report%20(CEN19LA322)-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. --- 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.