# NTSB ANC05LA036: Piper PA-18, N9071D, Talkeetna, AK, February 16, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 16, 2005, 15:00 local (19:00 UTC) - Place: Talkeetna, AK - Coordinates: 62.490833, -149.699996 - Nearby events: https://openairdocs.org/map.md?lat=62.4908&lon=-149.7000&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 20, 2005 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA-AL-ANC FSDO 03 - NTSB case key (mKey): 61023 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC05LA036 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61023/pdf - Page: https://openairdocs.org/ntsb/ANC05LA036 ## Probable cause The pilot's selection of unsuitable terrain for takeoff, which resulted in ski assembly damage during the takeoff run from a frozen, snow-covered lake, and subsequent nose over during an emergency landing. Factors contributing to the accident were an overload failure of the ski tip retaining assembly, and a hidden obstruction on the surface of the lake. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - On ground/water encounter with terrain/water, takeoff - roll/run - terrain condition - hidden obstruction(s) (contributing factor) - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause) - terrain condition - water,frozen - Airframe/component/system failure/malfunction, takeoff - roll/run - landing gear,ski assembly - overload (contributing factor) - In flight collision with terrain/water, emergency landing after takeoff - terrain condition - snow covered - Nose over, emergency landing after takeoff ## Analysis The commercial certificated pilot was departing a snow-covered frozen lake in a ski-equipped airplane. The lake was covered by about one-and-a-half feet of snow. The pilot said the lake is about 1/4 mile long, and he was taking off toward the east. During the takeoff run, as the airplane was about to lift off, the left ski struck a bump, or unseen object of some kind in the snow. The left ski tip rotated downward, to a near vertical position, and the pilot indicated that the ski tip retaining cable and bungee were dangling loose. The pilot made an emergency landing on the lake, and during the touchdown, the tip of the left ski dug into the snow. The airplane nosed over and received substantial damage to the wings, fuselage, and empennage. ## Factual narrative On February 16, 2005, about 1500 Alaska standard time, a ski-equipped Piper PA-18 airplane, N9071D, sustained substantial damage when it nosed over during an emergency landing on a snow-covered, frozen lake, after a main landing gear ski was damaged during the takeoff roll on the same lake. The remote lake is about 15 miles north-northeast of Talkeetna, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight under Title 14, CFR Part 91, when the accident occurred. The airplane was operated by the pilot. The commercial certificated pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight was intended to return to Talkeetna, and no flight plan was filed, nor was one required. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on February 16, the pilot reported that he was departing a frozen lake, covered by about one-and-a-half feet of snow. The pilot said the lake is about 1/4 mile long, and he was taking off toward the east. During the takeoff run, as the airplane was about to lift off, the left ski struck a bump, or unseen object of some kind in the snow. The left ski tip rotated downward, to a near vertical position, and the pilot indicated that the ski tip retaining cable and bungee were dangling loose. The pilot made an emergency landing on the lake, and during the touchdown, the tip of the left ski dug into the snow. The airplane nosed over and received substantial damage to the wings, fuselage, and empennage. ## Aircraft - Registration: [N9071D](https://openairdocs.org/aircraft/N9071D), registered now, S/N 18-6437 (OpenAirDocs) - Reported make and model: Piper PA-18 - 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: 18-6437 - Airframe hours: 1304 - Engines: Lycoming O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Jason A. Sturgis - Registered owner: Johnson Contracting - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 1, 2005 - Departed: Talkeetna, AK - Destination: Talkeetna, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 25; injuries: none; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review June 1, 2004; seat: front; flight hours: 1,200 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 5 knots - Visibility: 50 statute miles - Lowest ceiling: none - Temperature: 18 °F - Altimeter: 29.94 inHg ## 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 20050216001739A](https://openairdocs.org/incident/20050216001739A), Feb 16, 2005: Piper PA18A150, Talkeetna, AK, Substantial damage. (-23) Without a thorough reconnaissance of a snow covered lake, the pilot took off and hit a snow drift or other unseen and unknown obstacle under the powder… ## Other investigations on N9071D (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 MKC90LA113](https://openairdocs.org/ntsb/MKC90LA113), May 20, 1990: Piper PA-18A (N9071D), Creve Coeur, MO, substantial damage. Probable cause: FUEL CONTAMINATION AND INADEQUATE PREFLIGHT. 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.