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Atlas / NTSB / SEA99LA157

NTSB CAROL · Event

Event SEA99LA157

1999-09-09 HILLSBORO, Oregon, United States Airport · 7S3 Minor 1 aircraft Status: Completed

Aircraft involved

Probable cause & findings

Loss of engine power due to fuel contamination.

Factual narrative

On September 9, 1999, about 1530 Pacific daylight time, a Piper PA-23-160 Apache, N4065P, registered to and operated by Scholls Oaks LLC, was substantially damaged during an off-airport forced landing following a complete loss of power. Visual meteorological conditions prevailed and no flight plan was filed for the 14 CFR Part 91 instructional flight. The private pilot student received minor injuries while the certified flight instructor was uninjured. The flight originated from Stark's Twin Oaks Airpark, Hillsboro, Oregon, approximately 30 minutes prior to the accident. According to the pilot's statement, water was found in the aircraft's main fuel tanks during the preflight inspection. After sumping the tanks several times, the water was believed to be removed and the pilot's departed for the flight. While maneuvering, the flight instructor intentionally failed and secured the right engine. A restart attempt of the right engine was unsuccessful, and the pilots elected to return to the airport. While turning an approximate three mile final, the aircraft's left engine failed. Approximately one quarter mile from the runway, the student initiated a left turn permitting a forced landing to an open field. While in the left turn, the aircraft contacted the terrain causing substantial damage to left wing and fuselage. A Federal Aviation Administration (FAA) inspector from the Portland, Oregon, Flight Standards District Office, inspected the wreckage and reported there was water in the aircraft's main fuel tanks. He also stated there was water found in the carburetor bowls of both engines. During the preflight inspection, water was found in the aircraft's main fuel tanks. After sumping the tanks several times, the pilots believed the water was removed. While maneuvering, the flight instructor intentionally failed and secured the right engine. A restart attempt of the right engine was unsuccessful and the pilots elected to return to the airport. While turning an approximate three mile final, the aircraft's left engine failed. Approximately one quarter mile from the runway, the student initiated a left turn permitting a forced landing to an open field. While in the left turn, the aircraft contacted the terrain. A post-accident inspection of the wreckage, revealed water in the aircraft's main fuel tanks and the carburetor bowls of both engines. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1999_SEA99LA157.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.

Related research

What the literature says.

Academic papers and agency reports matching this event's aircraft type or causal vocabulary (fuel contamination). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.

Browse the full corpus — academia portal ↗