# NTSB ANC07LA044: Piper PA-12, N78492, Koyukuk, AK, June 11, 2007 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: June 10, 2007, 17:00 local (Jun 11, 2007, 01:00 UTC) - Place: Koyukuk, AK - Coordinates: 65.136665, -159.224716 - Nearby events: https://openairdocs.org/map.md?lat=65.1367&lon=-159.2247&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report November 29, 2007 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Fairbanks, FSDO-01 - NTSB case key (mKey): 65959 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC07LA044 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/65959/pdf - Page: https://openairdocs.org/ntsb/ANC07LA044 ## Probable cause The pilot's inadequate compensation for a gusting tailwind during the landing roll, which resulted in a loss of control and a nose over. Factors contributing to the accident were the tailwind and wind gust. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - roll - weather condition - gusts (contributing factor) - weather condition - tailwind (contributing factor) - compensation for wind conditions - inadequate, pilot in command (cause) - Nose over, landing - roll ## Analysis The airline transport certificated pilot was attempting to land the tailwheel-equipped airplane on a mountain ridge under Title 14, CFR Part 91. He said landing uphill necessitated landing with a tailwind. He reported that during the landing roll a gust of wind picked up the tail, and rolled the airplane upside down. The pilot said the airplane sustained damage to both wings and the rudder. ## Factual narrative On June 10, 2007, about 1700 Alaska daylight time, a tailwheel-equipped Piper PA-12 airplane, N78492, sustained substantial damage when it nosed over while landing on a mountain ridge, about 41 miles northwest of Koyukuk, Alaska. The airplane was being operated by the pilot as a visual flight rules (VFR) personal cross-country flight under Title 14, CFR Part 91, when the accident occurred. The airline transport certificated pilot received serious injuries, and the sole passenger received minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed. The flight departed the Unalakleet Airport, Unalakleet, Alaska, about 1500. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on June 15, the pilot said the mountain ridge where he intended to land looked smooth, free of rocks, and flat on top. He said the ridge sloped upward about 8 degrees, and he intended to land upslope. The pilot said an upslope landing necessitated he land with what he estimated to be about a 5 knot tailwind. According to the pilot, after the main landing gear touched down the airplane rolled into a depression on the ridge, and he believed that rolling into the depression exposed the underside of the tail to the tailwind, which flipped the airplane onto its back. He said there were no preaccident mechanical anomalies with the airplane prior to the accident, and that both wings and the fuselage were damaged during the accident. ## Aircraft - Registration: [N78492](https://openairdocs.org/aircraft/N78492), registered now, S/N 12-3903, built 1947 (OpenAirDocs) - Reported make and model: Piper PA-12 - Registry model: [Piper PA-12](https://openairdocs.org/model/piper-pa-12) (registry code 7101202) (OpenAirDocs) - Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 12-3903 - Airframe hours: 1762 - Engines: Lycoming O-360-P 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: James Tweto - Airworthiness certificate: Standard, Normal; Standard, Utility - Last inspection: Annual, June 1, 2006 - Departed: PAUN, Unalakleet, AK - Destination: Koyukuk, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 52; injuries: serious; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review September 1, 2006; seat: front; flight hours: 20,000 total, 1,000 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 10 knots - Visibility: 10 statute miles - Temperature: 61 °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 20070610011389A](https://openairdocs.org/incident/20070610011389A), Jun 10, 2007: Piper PA12, Koyukuk, AK, Substantial damage. (-23) ELT heard 02:30 z by rcc cap nome notified downed aircraft N78942 located by hageland aviation charter flt # state trooper on flight communicated with… 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.