# NTSB ANC99LA015: Stinson 10A, N36755, Nondalton, AK, December 4, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: December 4, 1998, 14:55 local (18:55 UTC) - Place: Nondalton, AK - Coordinates: 59.959922, -154.869201 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=59.9599&lon=-154.8692&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 16, 2001 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 45458 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC99LA015 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/45458/pdf - Page: https://openairdocs.org/ntsb/ANC99LA015 ## Probable cause The pilot's continued operation of the airplane with known deficiencies, a failure of company maintenance personnel to replace an inoperative fuel gauge, and subsequent fuel exhaustion. Factors in the accident were siphoning of fuel from the right wing fuel cap, and slush covered terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, cruise - fluid,fuel - exhaustion (cause) - operation with known deficiencies in equipment - continued, pilot in command (cause) - engine instruments,fuel quantity gage - inoperative (contributing factor) - fuel system,cap - siphoning (contributing factor) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, emergency descent/landing - terrain condition - slush covered (contributing factor) - Nose over, emergency descent/landing ## Analysis The certificated commercial pilot, and the sole passenger, departed for an on-demand air taxi flight over remote terrain. The passenger was conducting moose counting research for the Alaska Department of Fish and Game. The airplane carried four hours of fuel divided between two wing mounted fuel tanks. Each fuel tank is equipped with an electric fuel gauge. After flying for two hours with the left fuel tank selected, the fuel in the left tank was almost exhausted, and the pilot switched to the right fuel tank. He then flew for about 1.5 hours on the right tank before the engine suddenly quit. The pilot switched back to the left tank and climbed to about 1,000 feet above the ground. After about 6 minutes on the left tank, the engine quit running again. The pilot selected an emergency landing area on a small, frozen pond. The surface of the pond contained slushy ice and drifted snow. During the landing roll, the airplane entered deep snow and nosed over. The passenger reported she flew in the accident airplane two days before the accident. During that flight, she noticed the right fuel gauge in the airplane was inoperative. During the accident flight, two days later, she again noticed the right fuel gauge was still inoperative. Following recovery of the airplane, evidence of fuel staining was observed on the upper surface of the right wing, adjacent to the right fuel cap. ## Factual narrative On December 4, 1998, about 1455 Alaska standard time, a tundra tire equipped Stinson 10A airplane, N36755, sustained substantial damage during a forced landing, about 9 miles east of Nondalton, Alaska. The airplane was being operated as a visual flight rules (VFR) domestic on-demand passenger flight under Title 14 CFR Part 135 when the accident occurred. The airplane was operated by Lake Clark Air Inc., Port Alsworth, Alaska. The certificated commercial pilot, and the sole passenger, were not injured. Visual meteorological conditions prevailed. VFR company flight following procedures were in effect. The flight originated from a private airstrip at Port Alsworth, Alaska, at 1139. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on December 6, 1998, at 1000, the pilot reported the flight was conducted for the Alaska Department of Fish and Game. The passenger was conducting a moose count. The pilot said that after departure with full fuel tanks, he flew for two hours with the left fuel tank selected. After two hours of flight, the fuel in the left tank was almost exhausted, and the pilot switched to the right fuel tank. He then flew for about 1.5 hours on the right tank before the engine suddenly quit. The pilot switched back to the left tank and climbed to about 1,000 feet above the ground. After about 6 minutes on the left tank, the engine quit running again. The pilot selected an emergency landing area on a small, frozen pond. The surface of the pond contained slushy ice and drifted snow. During the landing roll, the airplane entered deep snow and nosed over. The airplane received damage to the left wing lift strut, the rudder, and the right wing tip. The operator reported the airplane is equipped with a 150 horsepower engine. The airplane has two wing mounted fuel tanks that contain 20 gallons each. Total useable fuel is 36 gallons. The fuel selector has positions for left, right, and off. Each fuel tank has an electric fuel gauge. The passenger was contacted by telephone and interviewed by the NTSB IIC. The passenger reported she flew in the accident airplane two days before the accident. During that flight, she noticed the right fuel gauge in the airplane was inoperative. During the accident flight, two days later, she again noticed the right fuel gauge was still inoperative. The operator reported that when the airplane was recovered from the accident site, evidence of fuel staining was observed on the upper surface of the right wing, adjacent to the right fuel cap. A Federal Aviation Administration (FAA) operations inspector with the Anchorage Flight Standards District Office, Anchorage, Alaska, inspected the airplane after it was recovered. He found evidence of fuel staining on the right wing, adjacent to the right wing fuel cap. ## Aircraft - Registration: [N36755](https://openairdocs.org/aircraft/N36755), registered now, S/N 8168, built 1941 (OpenAirDocs) - Reported make and model: Stinson 10A - Registry model: [Stinson 10A](https://openairdocs.org/model/stinson-10a) (registry code 8632102) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 8168 - Airframe hours: 4359 - Engines: Lycoming O-320-A2B 150 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Lake Clark Air Inc. - Registered owner: Sonnet Alsworth - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, November 14, 1998, 15 hours before - Departed: PORT ALSWORTH, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 29; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 5,724 total, 26 in this make and model, 5,621 as pilot in command, 348 in the last 90 days, 68 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 325° at 2 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 21 °F, dew point 18 °F - Altimeter: 29.00 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 19981204039799A](https://openairdocs.org/incident/19981204039799A), Dec 4, 1998: Stnson 10ASTNSON, Nondalton, AK, Substantial damage. (.19) On December 4, 1998, about 1455 Alaska standard time, a tundra tire equipped Stinson 10A airplane, N36755, sustained substantial damage during a forced… ## Other investigations on N36755 (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 ANC75FAG56](https://openairdocs.org/ntsb/ANC75FAG56), Nov 16, 1974: Stinson 10A (N36755), Tyonek, AK, substantial damage 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.