# NTSB GAA16CA252: Piper PA 20, N5589H, Nikolai Creek, AK, May 19, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: May 18, 2016, 19:00 local (May 19, 2016, 03:00 UTC) - Place: Nikolai Creek, AK - Coordinates: 61.104442, -151.37416 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.1044&lon=-151.3742&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Nose over/nose down](https://openairdocs.org/ntsb-events/096) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 12, 2016 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: Federal Aviation Administration - NTSB case key (mKey): 93226 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA16CA252 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93226/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93226 - Page: https://openairdocs.org/ntsb/GAA16CA252 ## Probable cause The pilot's selection of an unsuitable takeoff area resulting in an airplane nose over during the takeoff roll. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Runway/land/takeoff/taxi surface: wet surface](https://openairdocs.org/ntsb-findings/03023010): Environmental issues › Physical environment · Effect on equipment (probable cause); cases with it: [Piper PA-20, 1 case](https://openairdocs.org/ntsb-findings/03023010/cases.md?model=7102002), [All aircraft, 141 cases](https://openairdocs.org/ntsb-findings/03023010/cases.md) - [Terrain: wet/muddy terrain](https://openairdocs.org/ntsb-findings/03021035): Environmental issues › Physical environment · Decision related to condition (probable cause); cases with it: [Piper PA-20, 1 case](https://openairdocs.org/ntsb-findings/03021035/cases.md?model=7102002), [All aircraft, 110 cases](https://openairdocs.org/ntsb-findings/03021035/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Piper PA-20, 5 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7102002), [All aircraft, 3,100 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Nose over/nose down](https://openairdocs.org/ntsb-events/096) (defining event); cases with it: [Piper PA-20, 6 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=7102002), [All aircraft, 2,289 cases](https://openairdocs.org/ntsb-events/096/sequence.md) - [Takeoff: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-20, 11 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7102002), [All aircraft, 10,154 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis According to the pilot of the tailwheel landing gear-equipped airplane, he took off from grassy, wet, down sloping terrain. He recalled that he walked the area of intended takeoff and found no obstacles that would prevented a safe takeoff. However, he reported that during the takeoff roll, he kept the airplane tailwheel off of the ground, while rolling down slope, and the airplane main landing gear wheels rolled over a patch of mud creating a pivot point, and the airplane nosed over. The airplane sustained substantial damage to the vertical stabilizer, rudder, and wing struts. The pilot reported that there were not any mechanical malfunctions or anomalies with any portion of the airplane, prior to the takeoff roll that would have precluded normal flight operations. ## Factual narrative According to the pilot of the tailwheel-equipped airplane, he took off from grassy, wet, down sloping terrain. He recalled that he walked the area of intended takeoff and found no obstacles that would prevented a safe takeoff. However, he reported that during the takeoff roll, he kept the airplane tailwheel off of the ground, while rolling down slope, and the airplane main landing gear wheels rolled over a patch of mud creating a pivot point, and the airplane nosed over. The airplane sustained substantial damage to the vertical stabilizer, rudder, and wing struts. The pilot reported that there were not any mechanical malfunctions or anomalies with any portion of the airplane, prior to the takeoff roll that would have precluded normal flight operations. ## Aircraft - Registration: [N5589H](https://openairdocs.org/aircraft/N5589H), registered now, S/N 20-651, built 1951 (OpenAirDocs) - Reported make and model: PIPER PA 20 (150) - Registry model: [Piper PA-20](https://openairdocs.org/model/piper-pa-20) (registry code 7102002) (OpenAirDocs) - Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 20-651 - Year built: 1951 - Airframe hours: 1004.6 - Engines: LYCOMING O-320-A 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 7, 2016 - Departed: PALH, Anchorage, AK - Destination: West Cook Inlet, AK - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 29; injuries: none; airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1; last flight review December 9, 2015; seat: left; restraint: lap only; flight hours: 4,149 total, 95 in this make and model, 3,393 as pilot in command, 201 in the last 90 days, 37 in the last 30 days ## Weather - Conditions: Visual (VMC), Night - Wind: 230° at 13 knots, gusting 23 - Visibility: 10 statute miles - Lowest ceiling: 6,500 ft overcast - Temperature: 50 °F, dew point 43 °F - Altimeter: 30.09 inHg - Observed at: PAEN, 32 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 20160518014349A](https://openairdocs.org/incident/20160518014349A), May 18, 2016: Piper PA-20, Tyonek, AK, Substantial damage. During take off roll tires hit muddy spot and aircraft flipped over coming to rest upside down ## Other investigations on N5589H (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 ANC03LA047](https://openairdocs.org/ntsb/ANC03LA047), Apr 23, 2003: Piper PA-20 (N5589H), Palmer, AK, substantial damage. Probable cause: The pilot's failure to maintain directional control of the airplane during the landing roll which resulted in an inadvertent ground loop and collapse of the left main landing gear. ## Docket (2 files) The files NTSB released with the investigation on September 1, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93226. 2.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40444085&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photo (Courtesy of Pilot) (item 2, .PDF, 1 photo, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40444086&FileExtension=.PDF&FileName=Photo%20(Courtesy%20of%20Pilot)-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.