# NTSB LAX98LA089: Hiller UH-12E, N4027Z, Chico, CA, February 13, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: February 13, 1998, 11:30 local (19:30 UTC) - Place: Chico, CA - Coordinates: 39.740684, -121.829193 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.7407&lon=-121.8292&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 3, 1999 - Report: Approved by Office Director - NTSB case key (mKey): 30034 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX98LA089 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/30034/pdf - Page: https://openairdocs.org/ntsb/LAX98LA089 ## Probable cause Fuel exhaustion due to the pilot's failure to ensure that an adequate fuel supply was onboard. A contributing factor was related to the fuel quantity gage's erroneous indication of fuel. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, maneuvering - aerial application - engine instruments,fuel quantity gage - false indication (contributing factor) - fuel supply - inadequate, pilot in command (cause) - fluid,fuel - exhaustion (cause) - In flight collision with terrain/water, emergency descent/landing - terrain condition - open field ## Analysis During an aerial application flight over an orchard at 40 feet above ground level, the pilot experienced a total loss of engine power. Unable to enter an autorotation due to the low altitude, the pilot landed hard in an open field, and the helicopter was substantially damaged. An examination of the helicopter revealed it was out of fuel. According to the pilot, prior to the mishap the fuel quantity gage had indicated 12 gallons remained in the tank, and evidently the fuel float had become stuck in the tank. The FAA coordinator reported that the conditions which may have produced the discrepancy could not be duplicated during the postimpact testing. However, during the examination when the fuel quantity sender arm was manipulated the float could be induced to hang up vertically. Then, when lowered to the bottom of the tank, the fuel quantity would read 12 gallons. All other system circuitry and component tests were negative. No specific mechanical defect was established. ## Factual narrative On February 13, 1998, at 1130 hours Pacific standard time, a Hiller UH-12E, N4027Z, owned and operated by Chico Aerial Applicators, Chico, California, experienced a total loss of engine power during an aerial application flight. The pilot reported that he was too low to enter an autorotation, and the helicopter touched down hard in an open field a few miles from the Chico Airport. The helicopter was substantially damaged, and the commercial pilot was not injured. Visual meteorological conditions prevailed. The flight originated from Chico at 1100. The pilot verbally stated that seconds prior to experiencing the loss of engine power he heard two loud "bang" sounds and then the engine failed. In the pilot's completed report, he reported that the engine lost power at 40 feet above ground level while he was spraying an orchard. The pilot further reported that an examination of the helicopter revealed it was out of fuel. According to the pilot, prior to and following the mishap, the fuel quantity gage indicated 12 gallons remained in the tank and evidently the fuel float had become stuck in the tank. According to the Federal Aviation Administration (FAA) coordinator, the fuel tank quantity gage and its associated erroneous reading was examined and the discrepancy that the pilot reportedly observed could not be duplicated during the postimpact examination. The FAA reported that, however, during the examination when the fuel quantity sender arm was manipulated the float could be induced to hang up vertically. Then, when lowered to the bottom of the tank, the fuel quantity would read 12 gallons. All other system circuitry and component tests were negative. No specific mechanical defect was established. ## Aircraft - Registration: [N4027Z](https://openairdocs.org/deregistered/N4027Z-2018-02-13), registration cancelled 2018-02-13, S/N 5095, built 1979 (OpenAirDocs) - Reported make and model: Hiller UH-12E - Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs) - Registry engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 5095 - Airframe hours: 3230 - Engines: Lycoming O-540V 305 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Chico Aerial Applicators - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, August 19, 1997, 40 hours before - Departed: CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 27,000 total, 900 in this make and model, 50 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 5 knots - Visibility: 5 statute miles - Temperature: 55 °F - Altimeter: 30.00 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 19980213001239A](https://openairdocs.org/incident/19980213001239A), Feb 13, 1998: Hiller UH12E, Chino, CA, Substantial damage. Lost power on spray run. Landed hard. Engine made 2 loud bangs prior stopping. (.4)during an aerial application flight over an orchard at 40 feet above ground… 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.