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Atlas / NTSB / LAX99LA237

NTSB CAROL · Event

Event LAX99LA237

1999-06-30 WILLIAMS, California, United States None 1 aircraft Status: Completed

Registry · N7173F

FAA Aircraft Registry record.

Make / Model

HILLER UH-12E

TCDS

4H11 · SIAM HILLER HOLDINGS INC

Engine

ALLISON 250-C20 SER (420 hp)

Seats / Engines

4 seats · 1 engine

Last airworthiness date

19910805

ADS-B equipped

Yes — Mode-S A998D5

Registrant of record

FOUR CREEKS AVIATION INC

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The pilot's inadequate preflight planning and verification that fuel was available for the intended flight. A factor was the fuel quantity false indication.

Factual narrative

On June 30, 1999, about 0700 hours Pacific daylight time, a Hiller UH-12ET, N7173F, was substantially damaged during a forced landing in a rice field at Williams, California. The commercial pilot was not injured. The helicopter was being operated by Pacific Valley Aviation of Colusa, California, under the provisions of 14 CFR Part 137. A company visual flight plan was filed. Visual meteorological conditions prevailed for the local area agricultural flight, which originated near the field to be sprayed about 0630. The pilot stated that the engine abruptly quit while spraying the rice field and the forced landing resulted in the severing of the tail boom. He reported the turbine powered helicopter had been fueled the day before the accident, however, he did not visually confirm it. He had only flown 0.5 hours during this flight. Subsequent examination of the fuel system revealed a broken wire at the aft liquidometer. According to the UH-12E maintenance manual, an open circuit between pin A of the fuel gauge and pin C of the aft tank liquidometer would cause the gauge to indicate 34 gallons when the tank is empty. The pilot/operator failed to file a Safety Board Pilot Operator Accident Report, form 6120.1/2. While spraying a rice field the engine suddenly quit. The pilot force landed in the field severing the tail boom. The pilot reported the turbine powered helicopter had been fueled the day before the accident, however, he did not visually confirm it. The aircraft had only flown 0.5 hours during this flight. Examination of the fuel system revealed a broken wire in the fuel quantity indicating system. According to the maintenance manual for this helicopter, the open circuit caused by the wire breakage will cause a fuel quantity indication of 34 gallons when the tank is empty. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12

Verbatim from NTSB's published report. Source file NTSB_1999_LAX99LA237.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 (maintenance). 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 ↗