# NTSB GAA18CA320: Piper PA 12, N3937M, Nulato, AK, June 2, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: June 1, 2018, 23:30 local (Jun 2, 2018, 07:30 UTC) - Place: Nulato, AK - Coordinates: 65, -159.416671 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=65.0000&lon=-159.4167&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 18, 2019 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 97390 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA18CA320 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97390/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97390 - Page: https://openairdocs.org/ntsb/GAA18CA320 ## Probable cause The pilot’s improper landing flare, which resulted in a hard landing on upsloping terrain, and his subsequent failure to maintain adequate airspeed and his exceedance of the airplane’s critical angle of attack during an attempted go-around, which resulted in an 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: [Piper PA-12, 7 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=7101202), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-12, 7 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=7101202), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) - [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-12, 5 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md?model=7101202), [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-12, 51 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7101202), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Terrain: sloped/uneven terrain](https://openairdocs.org/ntsb-findings/03021017): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Piper PA-12, 3 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md?model=7101202), [All aircraft, 270 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Piper PA-12, 8 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=7101202), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) - [Landing-aborted after touchdown: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Piper PA-12, 17 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=7101202), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing-aborted after touchdown: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Piper PA-12, 36 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=7101202), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that, while landing off airport on an upsloping ridge, the tailwheel-equipped airplane "touched down harder than preferred." He applied full throttle, initiated a go-around, and attempted to turn toward the down-sloping side of the hill. The airplane briefly became airborne, but it then aerodynamically stalled and nosed down into the tundra. The airplane sustained substantial damage to the engine mount. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Factual narrative The pilot reported that, while landing off airport on an upslope of a ridge, the tailwheel-equipped airplane "touched down harder than preferred". He applied full throttle, initiated a go-around, and attempted to turn towards the downslope side of the hill. The airplane briefly became airborne but then aerodynamically stalled and nosed down into the tundra. The airplane sustained substantial damage to the engine mount. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N3937M](https://openairdocs.org/aircraft/N3937M), registered now, S/N 12-2825 (OpenAirDocs) - Reported make and model: PIPER PA 12 (NO SERIES) - Registry model: [Piper PA-12](https://openairdocs.org/model/piper-pa-12) (registry code 7101202) (OpenAirDocs) - Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 12-2825 - Year built: 1947 - Engines: LYCOMING O-320 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 12, 2018 - Departed: GAL, Galena, AK - Destination: NUL, Nulato, AK - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review February 24, 2018; seat: front; restraint: 3-point; flight hours: 315.3 total, 211.1 in this make and model, 252.5 as pilot in command, 20.6 in the last 90 days, 16.2 in the last 30 days, 2.5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Dusk - Wind: 250° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 55 °F, dew point 39 °F - Altimeter: 30.03 inHg - Observed at: PAKV, 44 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 20180601006809A](https://openairdocs.org/incident/20180601006809A), Jun 1, 2018: Piper PA-12, Nulato, AK, Substantial damage. Pilot decided to land on a ridge top. He made a first pass and drug a wheel to check the surface. On the second pass, he miss judged his height and speed. He… ## Other investigations on N3937M (1) 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 ANC22FA066](https://openairdocs.org/ntsb/ANC22FA066), Aug 11, 2022: Piper PA-12 (N3937M), Arctic Village, AK, substantial damage, 1 fatal. Probable cause: The pilot’s decision to depart in turbulent and gusting wind conditions, which resulted in a loss of control and impact with terrain. ## Docket (2 files) The files NTSB released with the investigation on October 3, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97390. 1.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 619 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467168&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photo (item 2, .PDF, 1 photo, 835 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467169&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.