# NTSB ANC00TA109: Piper PA-18, N125FG, Port Heiden, AK, August 29, 2000 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Final report - Date: August 29, 2000, 15:40 local (23:40 UTC) - Place: Port Heiden, AK - Coordinates: 56.95935, -158.579223 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=56.9594&lon=-158.5792&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 2 serious - Status: Completed, report July 2, 2001 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 51768 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC00TA109 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/51768/pdf - Page: https://openairdocs.org/ntsb/ANC00TA109 ## Probable cause The pilot's inadequate weather evaluation and in-flight planning/decisions. Factors in the accident were turbulence, and a downdraft. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, cruise - weather condition - downdraft (contributing factor) - weather evaluation - inadequate, pilot in command (cause) - weather condition - turbulence (contributing factor) - in-flight planning/decision - inadequate, pilot in command (cause) - In flight collision with object, descent - object - tree(s) ## Analysis The commercial certificated pilot departed with a biologist on a CFR Part 91 government flight, to conduct fish surveys in remote areas of the Alaska Peninsula. The point of departure was about 51 miles southwest of the accident site. Upon departure, the weather conditions included calm winds, and small clouds over high, mountainous terrain. As the survey continued into a coastal bay area on the east side of the Alaska Peninsula, the wind began to blow from the southwest, disturbing the water surface of the bay and streams. The pilot decided to discontinue the survey and return to the departure airport, and began heading in a southwest direction. The wind continued to increase with occasional turbulence. While in cruise flight about 1,200 feet msl in the area of a small saddle between two low hills, the airplane began to lose altitude in a strong downdraft. The pilot added full power, but the airplane continued to descend. He observed trees below him that were being flattened by the downdraft. He attempted to turn right, away from the side of one small hill, but a sharply increased ground speed prompted him to turn back into the prevailing wind. The airplane continued toward the ground, and the pilot said he lowered the nose of the airplane into an area of tall alders to make contact with terrain with some degree of control. During the collision with the trees, the engine and firewall were torn off the front of the airplane, and the wings were displaced rearward. The passenger reported that during the downdraft, his clipboard was pinned against the cabin roof. The closest official weather observation station is about 35 miles west of the accident site, along the west side of the Alaska Peninsula. An automated weather observation system was reporting, in part: Wind, 240 degrees (true) at 36 knots, gusts to 41 knots. ## Factual narrative On August 29, 2000, about 1540 Alaska daylight time, a tundra tire equipped Piper PA-18 airplane, N125FG, sustained substantial damage after colliding with terrain, about 35 miles east of Port Heiden, Alaska, at latitude 56 degrees, 48.6 minutes north, and longitude 157 degrees, 34.8 minutes west. The airplane was being operated as a visual flight rules (VFR) government flight under Title 14, CFR Part 91, when the accident occurred. The airplane was registered to, and operated by, the State of Alaska, Department of Fish and Game, Kodiak, Alaska. The commercial certificated pilot, and the sole passenger, a State of Alaska biologist, received serious injuries. Visual meteorological conditions prevailed. VFR company flight following procedures were in effect. During an interview with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on September 6, 2000, the pilot reported he departed Chignik Lake airport, Chignik, Alaska, about 1000, to conduct salmon fish surveys in several streams on the Alaska Peninsula. Chignik is about 51 miles southwest of the accident site. He said that when they departed Chignik, the weather conditions included calm winds, and small clouds over high, mountainous terrain. After stopping for a break at Coho Beach, about 22 miles northeast of the accident site, the survey continued southwesterly at 1515 into the area of Amber Bay (40 miles east of Port Heiden). The wind began to blow from the southwest, disturbing the water surface of the bay and streams. The pilot decided to discontinue the survey and return to Chignik, heading in a southwest direction. The wind continued to increase with occasional turbulence. The pilot said he was in cruise flight about 1,200 feet msl in the area of a small saddle between two low hills, located between Amber Bay and Aniakchak Bay, along the east side of the Alaska Peninsula. As the flight approached the saddle, the airplane began to lose altitude in a strong downdraft. He added full power, but the airplane continued to descend. He observed trees below him that were being flattened by the downdraft. He attempted to turn right, away from the side of one small hill, but a sharply increased ground speed prompted him to turn back into the prevailing wind. The airplane continued toward the ground, and the pilot said he lowered the nose of the airplane into an area of tall alders to make contact with terrain with some degree of control. During the collision with the trees, the engine and firewall were torn off the front of the airplane, and the wings were displaced rearward. In a telephone interview with the NTSB IIC on September 5, 2000, the passenger reported that during the downdraft, his clipboard was pinned against the cabin roof. The closest official weather observation station is Port Heiden, located along the west side of the Alaska Peninsula. On August 29, 2000, at 1535, an automated weather observation system was reporting, in part: Wind, 240 degrees (true) at 36 knots, gusts to 41 knots; visibility, 8 statute miles; clouds and sky condition, few at 2,600 feet, few at 3,000 feet, 4,400 feet overcast; temperature, 52 degrees F; dew point, 40 degrees F; altimeter, 30.09 inHg. ## Aircraft - Registration: [N125FG](https://openairdocs.org/aircraft/N125FG), registered now, S/N 18-1046, built 1951 (OpenAirDocs) - Reported make and model: Piper PA-18 - Registry model: [Piper PA-18-125](https://openairdocs.org/model/piper-pa-18-125) (registry code 7101812) (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: 18-1046 - Airframe hours: 6554 - Engines: Lycoming O-320-B2B 160 horsepower reciprocating - Damage: Substantial damage - Flight: Part 91 - Registered owner: State Of Alaska - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 4, 2000, 65 hours before - Departed: COHO BEACH, AK - Destination: AK79, CHIGNIK, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: front; flight hours: 3,000 total, 160 in this make and model, 2,950 as pilot in command, 200 in the last 90 days, 75 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 225° at 35 knots, gusting 50 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 55 °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 20000829042339A](https://openairdocs.org/incident/20000829042339A), Aug 29, 2000: Piper PA18125, Port Heiden, AK, Substantial damage. (-23) As per standard fish and game procedures, pilot flew up to the head of the canyon, turned and proceeded to descend and fly downstream in order to count… ## Other investigations on N125FG (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 ANC95TA067](https://openairdocs.org/ntsb/ANC95TA067), Jun 3, 1995: Piper PA-18-150 (N125FG), Sand Point, AK, substantial damage. Probable cause: The premature castoring of the tailwheel steering mechanism. A factor associated the accident is the added degree of difficulty in handling airplanes equipped with oversize 'tundra' tires. 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.