# NTSB GAA18CA351: Cessna 185, N9964X, Big Lake, AK, June 15, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: June 15, 2018, 11:00 local (19:00 UTC) - Place: Big Lake, AK - Coordinates: 61.535556, -149.813888 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.5356&lon=-149.8139&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 18, 2019 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 97488 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA18CA351 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97488/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97488 - Page: https://openairdocs.org/ntsb/GAA18CA351 ## Probable cause The pilot’s inability to maintain directional control during the landing roll due to a flat tire. ## 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: [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Landing gear system: wheel/ski/float](https://openairdocs.org/ntsb-findings/01023246): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [All aircraft, 48 cases](https://openairdocs.org/ntsb-findings/01023246/cases.md) - [Runway/land/takeoff/taxi surface: soft surface](https://openairdocs.org/ntsb-findings/03023020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [All aircraft, 264 cases](https://openairdocs.org/ntsb-findings/03023020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot of the tailwheel-equipped airplane reported that, during landing on a gravel airstrip, when the right main wheel touched down, the airplane veered right. He applied full left rudder to no avail. The right wheel exited the runway into soft, sandy soil, and the airplane nosed over. The airplane sustained substantial damage to the wings and empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot added that, after the accident, it was pointed out that the airplane had a flat tire and that there was a tire mark on the gravel runway from where the airplane touched down to where the airplane nosed over. ## Factual narrative The pilot of the tailwheel-equipped airplane reported that, during landing on a gravel airstrip, when the right main wheel touched down, the airplane veered to the right. He applied full left rudder to no avail. The right wheel exited the runway into soft, sandy soil and the airplane nosed over. The airplane sustained substantial damage to the wings and empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot added that, after the accident it was pointed out that the airplane had a flat tire, and that there was a tire mark on the gravel runway from where the airplane touched down to where the airplane nosed over. ## Aircraft - Registration: N9964X (not matched to a registry record) - Reported make and model: CESSNA 185 (UNDESIGNAT) - Category: Airplane - Serial number: 185-0164 - Year built: 1961 - Airframe hours: 2100.7 - Engines: CONT MOTOR IO-470-F 260 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility - Last inspection: Annual, May 19, 2018 - Departed: UUO, Willow, AK - Destination: BGQ, Big Lake, AK - Airport: BGQ, Big Lake, runway 25, 2,450 × 70 ft, gravel - Equipment: Stall warning system, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; injuries: none; private; airplane ratings: single-engine land; medical: class 1, waiver time limited special; last flight review May 17, 2017; seat: left; restraint: 3-point; flight hours: 366.2 total, 362.3 in this make and model, 374.5 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 48 °F - Altimeter: 29.96 inHg - Observed at: PAWS, 8 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 20180615007979A](https://openairdocs.org/incident/20180615007979A), Jun 15, 2018: Cessna 185, Big Lake, AK, Substantial damage. Pilot departed Big Lake and performed several touch and go landings at willow airport without incident. On landing at Big Lake the right tire was flat, the… ## Docket (2 files) The files NTSB released with the investigation on September 27, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97488. 1.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 888 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467024&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accident Picture (item 2, .PDF, 1 photo, 532 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467025&FileExtension=.PDF&FileName=Accident%20Picture-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.