# NTSB WPR09CA333: Bell 47G-2, N6768D, Turlock, CA, July 8, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 8, 2009, 11:00 local (18:00 UTC) - Place: Turlock, CA - Coordinates: 37.470275, -120.900558 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.4703&lon=-120.9006&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 30, 2009 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 74231 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09CA333 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74231/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74231 - Page: https://openairdocs.org/ntsb/WPR09CA333 ## Probable cause The pilot's failure to maintain rotor RPM while maneuvering at a low altitude. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Bell 47G-2, 2 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=1181008), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell 47G-2, 7 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1181008), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/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: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Bell 47G-2, 5 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1181008), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Bell 47G-2, 6 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1181008), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that while in a turn to reverse direction after completing a downwind spray run, "I noticed my RPMs getting low. As I was coming back down into the field I was rolling on throttle but could not get RPMs where I wanted them. I was hoping for the wind to help me, but there wasn't much wind at the time." The pilot stated that he pushed the cyclic forward to get airspeed, followed by pumping the collective to try to get power back. "I did this all the way until I hit the ground." The pilot reported that the helicopter impacted the ground in a flat, level attitude at about 40 miles per hour before skidding 30 feet and coming to a stop in an upright position. ## Factual narrative The pilot reported that while in a turn to reverse direction after completing a downwind spray run, "I noticed my RPMs getting low. As I was coming back down into the field I was rolling on throttle but could not get RPMs where I wanted them. I was hoping for the wind to help me, but there wasn't much wind at the time." The pilot stated that he pushed the cyclic forward to get airspeed, followed by pumping the collective to try to get power back. "I did this all the way until I hit the ground." The pilot reported that the helicopter impacted the ground in a flat, level attitude at about 40 miles per hour before skidding 30 feet and coming to a stop in an upright position. ## Aircraft - Registration: [N6768D](https://openairdocs.org/deregistered/N6768D-2018-03-15), registration cancelled 2018-03-15, S/N 2441, built 1959 (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: 2441 - Airframe hours: 19763 - Engines: Lycoming VO-435 240 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Titus J. Headings - Registered owner: Bettencourt Flying Service Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, February 23, 2009, 155 hours before - Departed: Turlock, CA - Destination: Turlock, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 25; injuries: none; commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review November 30, 2007; seat: left; flight hours: 544 total, 344 in this make and model, 474 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 176 °F ## 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 20090708013339A](https://openairdocs.org/incident/20090708013339A), Jul 8, 2009: Bell 47G2, Turlock, CA, Substantial damage. (-23) While conducting an aerial application, the aircraft was possible caught into settling with power. The pilot stated that he was performing a climbing… ## Other investigations on N6768D (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 CHI90DEP07](https://openairdocs.org/ntsb/CHI90DEP07), Jul 10, 1990: Bell 47-G2 (N6768D), Hatley, WI, substantial damage. Probable cause: THE PARTIAL LOSS OF POWER DUE TO STICKING INTAKE VALVES. ## Docket (1 files) The files NTSB released with the investigation on July 24, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74231. 660 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 660 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40316265&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.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.