# NTSB ANC18CA017: Piper PA 18-125, N1386A, Nikolai, AK, November 29, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: November 29, 2017, 12:02 local (21:02 UTC) - Place: Nikolai, AK - Coordinates: 62.293334, -153.361938 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=62.2933&lon=-153.3619&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 14, 2018 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 96523 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC18CA017 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96523/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96523 - Page: https://openairdocs.org/ntsb/ANC18CA017 ## Probable cause The pilot’s improper decision to contact an unsuitable landing surface, 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-18-125, 3 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7101812), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Runway/land/takeoff/taxi surface: snow/slush/ice covered surface](https://openairdocs.org/ntsb-findings/03023015): Environmental issues › Physical environment · Decision related to condition (probable cause); cases with it: [Piper PA-18-125, 1 case](https://openairdocs.org/ntsb-findings/03023015/cases.md?model=7101812), [All aircraft, 219 cases](https://openairdocs.org/ntsb-findings/03023015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [Piper PA-18-125, 2 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=7101812), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096) (defining event); cases with it: [Piper PA-18-125, 2 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=7101812), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that he had completed one high- and two low-reconnaissance flights over the snow-covered runway in his tundra-tire-equipped, tailwheel airplane. Before landing, he intended to fly a low pass and drag the main landing gear along the surface of the runway to determine the depth of the snow. He said that, as the main landing gear wheels touched down atop the frozen layer of crusty snow, the wheels broke through, and the airplane's tail began to rise. In an effort to prevent a nose-over, he applied full power, but the airplane subsequently nosed over. The airplane sustained substantial damage to the rudder and both left and right lift struts. The pilot reported that there were no preaccident mechanical malfunctions or failures that would have precluded normal operation. ## Factual narrative The pilot said that he had completed one high and two low reconnaissance flights over the snow-covered runway in his tundra tire-equipped, tailwheel airplane. Prior to landing, he intended to fly a low pass and drag the main landing gear along the surface of the runway to determine the depth of the snow, a maneuver commonly known as dragging the landing site. He said that as the main landing gear wheels touched down atop the frozen layer of crusty snow, the wheels broke through, and the airplane's tail began to rise. In an effort to prevent a nose over, he applied full power, but the airplane subsequently nosed over, sustaining substantial damage to the rudder and both left and right lift struts. The pilot stated there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation. In the recommendation section of the NTSB Accident/Incident Reporting Form 6120.1, the pilot stated that the accident may have been prevented if he would have utilized a flatter approach with increased airspeed similar to a glassy water approach while dragging the airstrip. ## Aircraft - Registration: [N1386A](https://openairdocs.org/aircraft/N1386A), registered now, S/N 18-1219, built 1951 (OpenAirDocs) - Reported make and model: PIPER PA 18-125 (125) - Registry model: [Piper PA-18-125](https://openairdocs.org/model/piper-pa-18-125) (registry code 7101812) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-1219 - Year built: 1951 - Airframe hours: 4321 - Engines: LYCOMING O-320 SERIES 160 horsepower reciprocating - Damage: Substantial damage - Flight: Public aircraft, Public use - Operator: State Of Alaska - Registered owner: State Of Alaska - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 6, 2017 - Departed: PAMC, McGrath, AK - Destination: PALH, Anchorage, AK - Flight plan: Company VFR - Airport: 8KA, Tatitna - Equipment: Handheld GPS, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: none; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review June 14, 2017; seat: front; restraint: 3-point; flight hours: 8,200 total, 7,600 in this make and model, 7,900 as pilot in command, 80 in the last 90 days, 20 in the last 30 days, 4.5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft broken - Temperature: 3 °F, dew point -2 °F - Altimeter: 28.97 inHg - Observed at: PAMC, 54 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 20171129022329A](https://openairdocs.org/incident/20171129022329A), Nov 29, 2017: Piper PA-18-125, Tatitna, AK, Substantial damage. The pilot was doing a test landing to determine the depth and drag of the snow. Upon the first pass and initial touchdown there was excessive and unforeseen… ## Other investigations on N1386A (3) 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 ANC03LA124](https://openairdocs.org/ntsb/ANC03LA124), Sep 23, 2003: Piper PA-18-150 (N1386A), Tanana, AK, substantial damage. Probable cause: The pilot's failure to maintain aircraft control during the landing roll, which resulted in an overrun and nose down. Factors contributing to the accident were gusty winds, and restricted aileron… - [NTSB ANC99LA113](https://openairdocs.org/ntsb/ANC99LA113), Aug 14, 1999: Piper PA-18 (N1386A), Anchorage, AK, substantial damage. Probable cause: The pilot's inadequate compensation for wind conditions during takeoff. A factor was a crosswind, and an inadvertent ground loop. - [NTSB ANC97LA091](https://openairdocs.org/ntsb/ANC97LA091), Jun 26, 1997: Piper PA-18 (N1386A), Chugiak, AK, substantial damage. Probable cause: water contamination in the fuel, the second pilot's inadequate preflight/preparation to ensure all water was drained from the airplane fuel tanks, and inadequate supervision by the first pilot (CFI).… ## Docket (1 files) The files NTSB released with the investigation on April 4, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96523. 1.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40461683&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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.