# NTSB ANC07LA099: Piper PA-18, N82022, Tok, AK, September 11, 2007 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 11, 2007, 06:30 local (14:30 UTC) - Place: Tok, AK - Coordinates: 63.2833333333333, -143.010277777778 - Nearby events: https://openairdocs.org/map.md?lat=63.2833&lon=-143.0103&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 28, 2008 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 66653 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC07LA099 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66653/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=66653 - Page: https://openairdocs.org/ntsb/ANC07LA099 ## Probable cause The pilot's selection of an unsuitable takeoff area and failure to maintain clearance from trees during takeoff. Contributing to the accident were soft, muddy terrain conditions. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, takeoff - initial climb - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause) - terrain condition - muddy (contributing factor) - clearance - not maintained, pilot in command (cause) - terrain condition - soft (contributing factor) - object - tree(s) ## Analysis The airline transport pilot, with a hunting client aboard, was departing from a soft, 900-foot long, mud and gravel-covered off-airport site that had an area of standing water near the departure end. During the takeoff run, the pilot said he was able to get the airplane airborne before reaching the area of standing water, but as the airplane began to climb, it struck a stand of trees at the departure end of the site. The airplane sustained structural damage to the wings, fuselage, and horizontal stabilizer. The pilot said that there were no preaccident mechanical anomalies with the airplane. ## Factual narrative On September 11, 2007, about 0630 Alaska daylight time, a tundra tire-equipped Piper PA-18 airplane, N82022, sustained substantial damage during takeoff from an off-airport site, about 50 miles north of Tok, Alaska. The airplane was being operated as a visual flight rules (VFR) other work use flight under Title 14, CFR Part 91, when the accident occurred. The airline transport pilot and the one passenger were not injured. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated at the off-airport site, and was en route to the Tok Airport, Tok. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on September 11, the pilot reported that on the morning of the accident, he awoke to a thick layer of ground fog, which delayed his departure. The purpose of the flight was to transport a hunting client to the Tok Airport at the conclusion of his guided hunting trip. After the fog had cleared, the pilot said he preheated the airplane's engine, removed any accumulation of frost from the wings, and did a preflight inspection. He said that the soft, 900-foot long, mud and gravel-covered site had an area of standing water near the departure end. During his takeoff run the pilot said that he was able to get the airplane airborne before reaching the area of standing water, but as the airplane began to climb, it struck a stand of trees at the departure end of the site. The airplane sustained structural damage to the wings, fuselage, and horizontal stabilizer. The pilot said that there were no preaccident mechanical anomalies with the airplane. ## Aircraft - Registration: [N82022](https://openairdocs.org/aircraft/N82022), registered now, S/N 18-7809113, built 1978 (OpenAirDocs) - Reported make and model: Piper PA-18 - 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: 18-7809113 - Airframe hours: 2040 - Engines: Lycoming O-320-B2B 160 horsepower reciprocating - Damage: Substantial damage - Flight: Other work use, Part 91 - Registered owner: Zachary D. Knaebel - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 1, 2006, 20 hours before - Departed: Tok, AK - Destination: TKJ, Tok, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review February 1, 2007; seat: front; flight hours: 3,500 total, 1,500 in this make and model, 3,400 as pilot in command, 200 in the last 90 days ## Weather - Conditions: Visual (VMC), Dawn - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 34 °F ## 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 20070911023439A](https://openairdocs.org/incident/20070911023439A), Sep 11, 2007: Piper PA18150, Tok, AK, Substantial damage. (-23) The pilot misjudged the softness/wetness of the departure end of the dirt airstrip and was unable to get airborne. Aircraft struck tall brush and crashed… ## Other investigations on N82022 (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 ANC95LA079](https://openairdocs.org/ntsb/ANC95LA079), Jun 22, 1995: Piper PA-18-150 (N82022), Fairbanks, AK, substantial damage. Probable cause: THE PILOT'S INADVERTENT STALL OF THE AIRPLANE. - [NTSB DEN78FQA51](https://openairdocs.org/ntsb/DEN78FQA51), Aug 15, 1978: Piper PA-18 (N82022), Albuquerque, NM, substantial damage ## Docket (1 files) The files NTSB released with the investigation on April 30, 2008, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=66653. 598 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 598 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40293458&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.