# NTSB GAA17CA473: Cessna 180, N9455C, Puntilla, AK, August 2, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 1, 2017, 19:00 local (Aug 2, 2017, 03:00 UTC) - Place: Puntilla, AK - Coordinates: 61.92361, -153.023605 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.9236&lon=-153.0236&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 14, 2018 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 95763 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA473 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95763/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95763 - Page: https://openairdocs.org/ntsb/GAA17CA473 ## Probable cause The airplane’s encounter with a downdraft while maneuvering at a low altitude, which resulted in the exceedance of the airplane’s critical angle of attack and a subsequent aerodynamic stall. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Cessna 180, 3 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=2072602), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/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 180, 65 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2072602), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Cessna 180, 2 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=2072602), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Cessna 180, 16 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=2072602), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Landing: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Cessna 180, 4 cases](https://openairdocs.org/ntsb-events/241/sequence.md?model=2072602), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 180, 6 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072602), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Cessna 180, 80 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=2072602), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-flare/touchdown: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 180, 54 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2072602), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cessna 180, 29 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2072602), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis According to the pilot, he made two passes over a dry creek bed to assess a potential landing site. The second pass was accomplished up-creek into rising terrain. The airplane was configured with full power and with flaps at 20°, and it was about 50 ft above ground level at 80 mph. The pilot reported that the airplane encountered a downdraft as it transitioned from overflying the trees to overflying the creek bed, which he attempted to correct, but the airplane aerodynamically stalled. Following the stall, the pilot attempted to land on a dry creek bed. The airplane touched down on the creek bed, then bounced and descended into a "dry cut channel." The airplane came to rest nose down in a near vertical position. The airplane was destroyed by a postcrash fire. According to the National Transportation Safety Board's Pilot Aircraft Accident Report, the pilot reported that the event could have been avoided by making the low pass along descending terrain at a higher airspeed. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. ## Factual narrative According to the pilot, he made two passes over a dry creek bed to assess a potential landing site. The second pass was accomplished up creek into rising terrain. The airplane was configured with full power, with flaps at 20° and flying about 50ft AGL and 80 MPH. The pilot reported that the airplane encountered a downdraft as the airplane transitioned from overflying the trees, to overflying the creek bed, which he attempted to correct, but the airplane aerodynamically stalled. Following the stall, the pilot attempted to land on a dry creek bed. The airplane touched down on the creek bed, then bounced and descended into a "dry cut channel". The airplane came to rest nose down and the airplane in a near vertical position. The airplane was destroyed by a post-crash fire. According to the National Transportation Safety Board's, Pilot Aircraft Accident Report, the pilot reported that the event could have been avoided by making the low pass along descending terrain at a higher airspeed. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N9455C](https://openairdocs.org/deregistered/N9455C-2020-09-04), registration cancelled 2020-09-04, S/N 31853, built 1955 (OpenAirDocs) - Reported make and model: CESSNA 180 (UNDESIGNAT) - Registry model: [Cessna 180](https://openairdocs.org/model/cessna-180) (registry code 2072602) (OpenAirDocs) - Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 31853 - Year built: 1955 - Airframe hours: 2883 - Engines: CONT MOTOR O-470J 225 horsepower reciprocating - Damage: Destroyed - Fire: On-Ground - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 3, 2016 - Departed: PAWS, Wasilla, AK - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 26; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review June 3, 2017; seat: left; restraint: lap only; flight hours: 305 total, 70 in this make and model, 277 as pilot in command, 55 in the last 90 days, 30 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Observed at: KPTI, 13 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 20170801015669A](https://openairdocs.org/incident/20170801015669A), Aug 1, 2017: Cessna 180, Skwentna, AK, Destroyed. Pilot was searching for landing sites for hunting. While at 60 foot AGL, 80 knots air speed, 20 degrees flaps, flying up hill. Pilot experienced a down draft.… ## Docket (2 files) The files NTSB released with the investigation on January 30, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95763. 3.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40459642&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photo (item 2, .PDF, 147 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40459643&FileExtension=.PDF&FileName=Photo-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.