# NTSB ANC99LA033: Cessna 180G, N4721U, Fairbanks, AK, March 14, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 14, 1999, 18:28 local (22:28 UTC) - Place: Fairbanks, AK - Coordinates: 64.900375, -148.159179 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=64.9004&lon=-148.1592&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 20, 2000 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 45955 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC99LA033 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/45955/pdf - Page: https://openairdocs.org/ntsb/ANC99LA033 ## Probable cause Water contamination of the fuel supply, and the pilot's inadequate preflight inspection to ensure all water was removed from the fuel supply. Factors in the accident were a wrinkle in the wing fuel tank bladder, and snow covered terrain. ## Analysis The certificated commercial pilot pushed the airplane out of a hanger and sumped the wing fuel tanks. The airplane remained outside throughout the day while the ambient temperature warmed. No further sumping of the wing tanks was conducted. After departure, the pilot reduced the engine power to level the airplane at the airport traffic pattern altitude. The engine began to run rough, and the pilot began an emergency landing approach to a snow-covered airstrip located near the approach end of an asphalt runway. The engine roughness diminished, and the pilot was cleared to land on the larger asphalt runway. The engine then quit. The airplane touched down in an area of snow between the end of the small airstrip and the beginning of the asphalt runway. The airplane nosed over, and received damage to the vertical stabilizer, the rudder, and the left wing lift strut. An examination of the airplane revealed a wrinkle in the left wing fuel bladder, and 3 ounces of water in the gascolator. ## Factual narrative On March 14, 1999, about 1828 Alaska standard time, a wheel equipped Cessna 180G airplane, N4721U, sustained substantial damage during an emergency landing at the Fairbanks International Airport, Fairbanks, Alaska. The airplane was being operated as a visual flight rules (VFR) local area personal flight when the accident occurred. The airplane was registered to, and operated by, the pilot. The certificated commercial pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at the Fairbanks Airport at 1825. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on March 15, 1999, at 1115, the pilot reported that after departure, he reduced engine power to level the airplane at 1,500 feet, which is the airport traffic pattern altitude. The engine began to run rough, and he began an emergency landing approach to the ski strip, runway 01 at the Fairbanks airport. The ski strip, 01/19, is a gravel surface runway 3,978 feet long and 75 feet wide, and is oriented on the same magnetic heading as runway 01R/19L. There is no lateral displacement between the two runways. The departure end of the ski strip 01 is displaced directly south of the approach end of runway 01R about 650 feet, and is intersected by taxiway B. The pilot said the engine roughness diminished, and he was cleared to land on runway 01R. The pilot said the engine then quit. The airplane touched down in an area of snow between the end of the ski strip 01, and the approach end of runway 01R. The airplane then nosed over, and received damage to the vertical stabilizer, the rudder, and the left wing lift strut. A Federal Aviation Administration (FAA) airworthiness inspector with the Fairbanks Flight Standards District Office (FSDO) examined the airplane on March 28, 1999, and interviewed the pilot. The inspector reported the pilot pushed the airplane out of a hanger, and sumped the wing fuel tanks. The airplane remained outside, and the ambient temperature warmed throughout the day. The pilot did not re-sump the airplane before departing. The inspector's examination of the airplane revealed a longitudinal wrinkle in the left wing fuel bladder. The wrinkle was positioned near the wing sump drain. The inspector also found about 3 ounces of water in the airframe gascolator. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, takeoff - initial climb - fluid,fuel - contamination,water (cause) - fuel system,tank - other (contributing factor) - aircraft preflight - inadequate, pilot in command (cause) - Forced landing, emergency descent/landing - Undershoot, emergency descent/landing - In flight collision with terrain/water, emergency descent/landing - terrain condition - snow covered (contributing factor) ## Aircraft - Registration: [N4721U](https://openairdocs.org/aircraft/N4721U), registered now, S/N 18051421, built 1964 (OpenAirDocs) - Reported make and model: Cessna 180G - Registry model: [Cessna 180G](https://openairdocs.org/model/cessna-180g) (registry code 2072616) (OpenAirDocs) - Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18051421 - Airframe hours: 2663 - Engines: Continental O-470-R 230 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Robert W. Taylor - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 1, 1998, 26 hours before - Airport: PAFA, Fairbanks International, runway 1R, 3,190 × 60 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 3,500 total, 275 in this make and model, 3,400 as pilot in command, 10 in the last 90 days, 8 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 13,000 ft broken - Temperature: 25 °F, dew point 12 °F - Altimeter: 29.00 inHg - Observed at: PAF ## 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 19990314014149A](https://openairdocs.org/incident/19990314014149A), Mar 14, 1999: Cessna 180G, Fairbanks, AK, Substantial damage. (.19) On March 14, 1999, about 1828 Alaska standard time, a wheel equipped Cessna 180G airplane, N4721U, sustained substantial damage during an emergency… ## Other investigations on N4721U (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 ANC25LA088](https://openairdocs.org/ntsb/ANC25LA088), Aug 19, 2025: Cessna 180G (N4721U), Delta Junction, AK, substantial damage. Probable cause: The pilot’s failure to maintain a rate of climb sufficient to clear obstacles during takeoff, resulting in a collision with tree-covered terrain. - [NTSB ANC81DAA06](https://openairdocs.org/ntsb/ANC81DAA06), Aug 2, 1980: Cessna 180 (N4721U), Fairbanks, 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.