# NTSB GAA19CA159: Piper PA18, N4100Z, Pullman, WA, March 9, 2019 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: March 9, 2019, 12:20 local (20:20 UTC) - Place: Pullman, WA - Coordinates: 46.735832, -117.088058 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.7358&lon=-117.0881&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: Minor injuries - Injuries: 1 minor - Status: Completed, report November 6, 2019 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 99090 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA19CA159 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99090/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99090 - Page: https://openairdocs.org/ntsb/GAA19CA159 ## Probable cause The pilot's selection of unsuitable terrain for landing, which resulted in a nose-over. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Piper PA-18-150, 51 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7101828), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Object/animal/substance: snow/ice](https://openairdocs.org/ntsb-findings/03022060): Environmental issues › Physical environment · Effect on operation (probable cause); cases with it: [Piper PA-18-150, 2 cases](https://openairdocs.org/ntsb-findings/03022060/cases.md?model=7101828), [All aircraft, 67 cases](https://openairdocs.org/ntsb-findings/03022060/cases.md) - [Runway/land/takeoff/taxi surface: snow/slush/ice covered surface](https://openairdocs.org/ntsb-findings/03023015): Environmental issues › Physical environment · Effect on operation; cases with it: [Piper PA-18-150, 7 cases](https://openairdocs.org/ntsb-findings/03023015/cases.md?model=7101828), [All aircraft, 219 cases](https://openairdocs.org/ntsb-findings/03023015/cases.md) - [Terrain: sloped/uneven terrain](https://openairdocs.org/ntsb-findings/03021017): Environmental issues › Physical environment · Effect on operation; cases with it: [Piper PA-18-150, 10 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md?model=7101828), [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: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-18-150, 115 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7101828), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Piper PA-18-150, 109 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=7101828), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Piper PA-18-150, 83 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=7101828), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot of the tailwheel- and ski-equipped airplane reported that, while landing off airport on a snow-covered ridge, the back of the right ski struck about a 6-inch-tall, firm snow drift. The right ski then pitched forward, the tip dug into the "crusty" snow, and the airplane nosed over. The airplane sustained substantial damage to the fuselage, empennage, and lift strut. 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 of the tailwheel, ski-equipped airplane reported that, while landing off airport, on a snow-covered ridge, the back of the right ski struck about a 6" tall, firm snow drift. The right ski then pitched forward, the tip dug into the "crusty" snow, and the airplane nosed over. The airplane sustained substantial damage to the fuselage, empennage, and lift strut. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N4100Z](https://openairdocs.org/aircraft/N4100Z), registered now, S/N 18-8114 (OpenAirDocs) - Reported make and model: Piper PA18 (150) - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-8114 - Year built: 1964 - Airframe hours: 5459.45 - Engines: Lycoming O-320-B2B 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: Annual, July 20, 2018 - Departed: PUW, Pullman/Moscow, WA - Destination: PUW, Pullman/Moscow, WA - Equipment: Electronic multifunction display, Electronic flight bag or handheld device, ADS-B, Satellite tracking device, Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: minor; private; airplane ratings: single-engine sea, single-engine land; medical: class 3, with waivers/limitations; last flight review May 27, 2017; seat: front; restraint: 4-point; flight hours: 2,379 total, 1,268 in this make and model, 2,379 as pilot in command, 38 in the last 90 days, 21 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Temperature: 16 °F, dew point 12 °F - Altimeter: 29.95 inHg - Observed at: KPUW, 1 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 20190309010669A](https://openairdocs.org/incident/20190309010669A), Mar 9, 2019: Piper PA-18-150, Pullman, WA, Substantial damage. Accident pilot operated off of puw airport to his own airstrip less than 1NM south of the airport. Aircraft equipped with wheel skiis. After takeoff pilot… ## Other investigations on N4100Z (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 WPR11CA072](https://openairdocs.org/ntsb/WPR11CA072), Dec 4, 2010: Piper PA-18-150 (N4100Z), Pullman, WA, substantial damage. Probable cause: The pilot's delayed application of carburetor heat while maneuvering, which resulted in a partial loss of engine power. ## Docket (2 files) The files NTSB released with the investigation on April 17, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99090. 761 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 473 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40471958&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accident Picture (item 2, .PDF, 1 photo, 288 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40471959&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.