# NTSB ANC12CA053: Piper PA-18-150, N9488D, Skwentna, AK, June 17, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: June 16, 2012, 17:00 local (Jun 17, 2012, 01:00 UTC) - Place: Skwentna, AK - Coordinates: 61.95, -151.366668 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.9500&lon=-151.3667&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi-from runway: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 4, 2012 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 84026 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC12CA053 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84026/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84026 - Page: https://openairdocs.org/ntsb/ANC12CA053 ## Probable cause The pilot’s selection of unsuitable terrain for taxi. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Piper PA-18A 150, 1 case](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=7101837), [All aircraft, 267 cases](https://openairdocs.org/ntsb-findings/03021000/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-18A 150, 6 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7101837), [All aircraft, 3,098 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. - [Taxi-from runway: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Piper PA-18A 150, 11 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=7101837), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Taxi-from runway: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-18A 150, 16 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7101837), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot landed the tailwheel-equipped airplane at a private airstrip. While taxiing to park, the right wheel dropped into a hidden, vegetation-covered, deep hole alongside the runway. The airplane then spun around, sustaining substantial damage to the empennage and left elevator. The pilot reported no preaccident mechanical problems with the airplane. ## Factual narrative The pilot landed the tailwheel-equipped airplane at a private airstrip. While taxiing to parking, the right wheel dropped into a hidden, vegetation covered, deep hole, alongside the runway. The airplane spun around, sustaining substantial damage to the empennage, and left elevator. The pilot reported no preaccident mechanical problems with the airplane. ## Aircraft - Registration: [N9488D](https://openairdocs.org/aircraft/N9488D), registered now, S/N 18-6740, built 1959 (OpenAirDocs) - Reported make and model: PIPER PA-18-150 - Registry model: [Piper PA-18A 150](https://openairdocs.org/model/piper-pa-18a-150) (registry code 7101837) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-6740 - Engines: Lycoming O-320 Series 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Beck Joseph S - Registered owner: Beck Joseph S - Airworthiness certificate: Standard, Normal - Departed: Wasilla, AK - Destination: Skwentna, AK - Airport: PVT, Shell Lake Airstrip, runway 15, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; injuries: none; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review April 28, 2011; seat: front; flight hours: 3,150 total, 1,000 in this make and model ## Weather - Conditions: Visual (VMC), Day - Visibility: 50 statute miles ## 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 20120616013259A](https://openairdocs.org/incident/20120616013259A), Jun 16, 2012: Piper PA-18A 150, Skwentna, AK, Substantial damage. On taxi after landing on grass strip, the right wheel rolled into a hole on the edge of the runway hidden by tall grass. The airplane spun around, causing… ## Other investigations on N9488D (2) 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 ANC06CA085](https://openairdocs.org/ntsb/ANC06CA085), Jul 7, 2006: Piper PA-18-180 (N9488D), Skwentna, AK, substantial damage. Probable cause: The pilot's selection of unsuitable terrain for landing, which resulted in a loss of control during the landing roll, and an on ground encounter with terrain. Factors associated with the accident are… - [NTSB SEA76DTI13](https://openairdocs.org/ntsb/SEA76DTI13), Sep 29, 1975: Piper PA-18A (N9488D), Fairfield, MT, substantial damage ## Docket (1 files) The files NTSB released with the investigation on July 27, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84026. 697 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 697 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40372838&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.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.