# NTSB CEN12CA435: Bell 47G-3B-2, N2919W, Treynor, IA, July 9, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 9, 2012, 07:09 local (12:09 UTC) - Place: Treynor, IA - Coordinates: 41.189723, -95.586669 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.1897&lon=-95.5867&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Fuel exhaustion](https://openairdocs.org/ntsb-events/192) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 9, 2012 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA/FSDO - NTSB case key (mKey): 84284 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12CA435 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84284/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84284 - Page: https://openairdocs.org/ntsb/CEN12CA435 ## Probable cause The pilot’s improper fuel management, which resulted in a loss of engine power due to fuel exhaustion. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Planning/preparation: fuel planning](https://openairdocs.org/ntsb-findings/02061030): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell 47G-3B-2, 1 case](https://openairdocs.org/ntsb-findings/02061030/cases.md?model=1181029), [All aircraft, 719 cases](https://openairdocs.org/ntsb-findings/02061030/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid management (probable cause); cases with it: [Bell 47G-3B-2, 1 case](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=1181029), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Fuel exhaustion](https://openairdocs.org/ntsb-events/192) (defining event); cases with it: [Bell 47G-3B-2, 1 case](https://openairdocs.org/ntsb-events/192/sequence.md?model=1181029), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md) - [Autorotation: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Bell 47G-3B-2, 2 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=1181029), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot performed a preflight inspection and noted that the 61-gallon fuel tank was just over a quarter full. After about 26 minutes of aerial application runs, the helicopter yawed left, and a warning light flickered. The pilot did not see which light had illuminated. Thinking it was a fuel problem, he checked the fuel quantity gauge, which read two needle-widths below a quarter tank. The pilot continued spraying, and several seconds later the turbine-engine stopped producing power. The pilot turned left and made an autorotation run-on landing to a field. After the helicopter came to a stop, the main rotor blades flexed downward and severed the tail boom. Approximately 1.75 gallons of fuel was drained from the two fuel tanks. The pilot reported that the usual fuel consumption was about 25 gallons per hour and the tanks had about 4 gallons of unusable fuel. The pilot said that there were no mechanical problems before the accident, and the engine was most likely starved of fuel due to the low fuel level and unusual attitudes inherent to helicopter aerial applications. ## Factual narrative The pilot performed a pre-flight inspection and noted the 61-gallon fuel tank was just over a quarter full. After about 26 minutes of aerial application runs, the helicopter yawed left and a warning light flickered. The pilot did not see which light had illuminated. Thinking it was a fuel problem, he checked the fuel quantity gauge, which read two needle-widths below a quarter tank. The pilot continued spraying and several seconds later the turbine-engine stopped producing power. The pilot turned left and made an autorotation run-on landing to a field. After the helicopter came to a stop, the main rotor blades flexed downward and severed the tail boom. Approximately 1.75 gallons of fuel was drained from the two fuel tanks. The pilot reported the usual fuel consumption was about 25 gallons per hour and the tanks had about 4 gallons of unusable fuel. The pilot said there were no mechanical problems prior to the accident and the engine was most likely starved of fuel due to the low fuel level and unusual attitudes inherent to helicopter aerial applications. ## Aircraft - Registration: [N2919W](https://openairdocs.org/deregistered/N2919W-2025-02-08), registration cancelled 2025-02-08, S/N 6823 (OpenAirDocs) - Reported make and model: BELL 47G-3B-2 - Registry model: [Bell 47G-3B-2](https://openairdocs.org/model/bell-47g-3b-2) (registry code 1181029) (OpenAirDocs) - Registry engine: [Lycoming TVO-435-GIA](https://openairdocs.org/engine/lycoming-tvo-435-gia) (registry code 41526, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 6823 - Airframe hours: 10129 - Engines: LYCOMING TV0-435 SER 280 horsepower turbo shaft - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Custom Air LLC - Registered owner: Custom Air LLC - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, May 29, 2012 - Departed: Treynor, IA - Destination: Treynor, IA - Airport: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: none; commercial; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, with waivers/limitations; seat: left; flight hours: 4,700 total, 850 in this make and model, 4,700 as pilot in command, 200 in the last 90 days, 100 in the last 30 days, 10 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day ## 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 20120709012379A](https://openairdocs.org/incident/20120709012379A), Jul 9, 2012: Bell 47G-3B-2, Treynor, IA, Substantial damage. As stated by the pilot, during aerial application while traveling north the aircraft momentarily torqued left and a warning light quickly flashed. A check of… ## Other investigations on N2919W (1) 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 SEA78FYM25](https://openairdocs.org/ntsb/SEA78FYM25), Apr 15, 1978: Bell 47G (N2919W), Kings Valley, OR, substantial damage ## Docket (4 files) The files NTSB released with the investigation on August 13, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84284. 1.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375073&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation - Pilot (item 2, .PDF, 98 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375092&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Pilot-Master.PDF - Adendum to Pilot's Original Statements (item 3, .PDF, 40 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40373859&FileExtension=.PDF&FileName=Adendum%20to%20Pilot%27s%20Original%20Statements-Redacted.PDF - Record of Conversation - Director of Maintenance, Custom Air (item 4, .PDF, 70 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40373857&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Director%20of%20Maintenance,%20Custom%20Air-Master.PDF 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.