# NTSB SEA83LA122: Bell 47G-2, N41721, Zillah, WA, June 11, 1983 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 11, 1983, 11:50 local (19:50 UTC) - Place: Zillah, WA - Coordinates: 46.409839, -120.230407 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.4098&lon=-120.2304&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - NTSB case key (mKey): 39709 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA83LA122 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/39709/pdf - Page: https://openairdocs.org/ntsb/SEA83LA122 ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, cruise - normal - fluid,fuel - exhaustion (contributing factor) - fuel supply - misjudged, pilot in command (cause) - engine instruments,fuel quantity gage - false indication (contributing factor) - preflight planning/preparation - inadequate, pilot in command (cause) - refueling - not performed, pilot in command (cause) - Forced landing, landing - flare/touchdown - terrain condition - none suitable (contributing factor) - autorotation - performed, pilot in command (contributing factor) - Hard landing, landing - flare/touchdown - terrain condition - high vegetation (contributing factor) ## Analysis THE ROTORCRAFT MADE A HARD LANDING AFTER COLLIDING WITH TREES DURING AN AUTOROTATION. THE ACFT HAD EXPERIENCED AN ENGINEFAILURE WHILE ON A REPOSITIONING FLIGHT BETWEEN AERIAL APPLICATION OPERATIONS AND WAS FORCED TO LAND. THE ACFT WAS AUTOROTATED INTO AN ORCHARD AND CONTACTED TREES, SUSTAINING SUBTANTIAL DAMAGE TO THE SKIDS, MAIN ROTOR BLADES AND TAIL BOOM. THE PILOT WAS UNINJURED. THE FLIGHT ORIGINATED FROM A TEMPORARY SITE A FEW MINUTES BEFORE THE MISHAP. INVESTIGATION REVEALED THE POWER LOSS WAS DUE TO FUEL EXHAUSTION. THE FUEL CELLS WERE EMPTY BUT THE FUEL GAUGES SHOWED FUEL REMAINING. THE ACFT WAS FUELED WITH 22 GALLONS OF FUEL.THE GAUGES READ ONE QUARTER-LEFT,ONE HALF-RIGHT. THE SYSTEM WAS DRAINED EMPTY. THE GAUGES READ ONE EIGHTH-LEFT,ONE QUARTER-RIGHT. ## Aircraft - Registration: [N41721](https://openairdocs.org/deregistered/N41721-2012-12-26), registration cancelled 2012-12-26, S/N 815 (OpenAirDocs) - Reported make and model: BELL 47G-2 - Registry model: [Bell 47G-2](https://openairdocs.org/model/bell-47g-2) (registry code 1181008) (OpenAirDocs) - Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 815 - Airframe hours: 7065 - Engines: LYCOMING VO-435 260 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Valicopters, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, June 10, 1983, 8 hours before - Departed: ZILLAH, WA - Destination: WAPATO, WA - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 4,372 total, 1,220 in this make and model, 4,040 as pilot in command, 202 in the last 90 days, 125 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 5 knots - Visibility: 50 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 37 °F - Altimeter: 29.00 inHg - Observed at: YKM, 13 nm away ## 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 19830611024879A](https://openairdocs.org/incident/19830611024879A), Jun 11, 1983: Bell 47G2, Zillah, WA, Substantial damage. Fuel exhaustion occurred en route to another spray site. Autorotated into trees. Fuel gauges were inaccurate. ## Other investigations on N41721 (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 SEA89LA098](https://openairdocs.org/ntsb/SEA89LA098), Jun 2, 1989: Bell 47G-2 (N41721), Buena, WA, destroyed. Probable cause: THE PILOT'S FAILURE TO MAINTAIN AN ADEQUATE VISUAL LOOKOUT AND CLEARANCE TO AVOID THE POWER LINES. - [NTSB SEA78DYM23](https://openairdocs.org/ntsb/SEA78DYM23), Apr 7, 1978: Bell 47G-2 (N41721), Goldendale, WA, 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.