# NTSB WPR11CA394: Bell 47G, N6260C, Porterville, CA, July 31, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 31, 2011, 11:00 local (18:00 UTC) - Place: Porterville, CA - Coordinates: 36.058887, -119.01667 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.0589&lon=-119.0167&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 17, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 81564 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11CA394 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81564/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81564 - Page: https://openairdocs.org/ntsb/WPR11CA394 ## Probable cause The pilot's decision to takeoff in a tailwind condition, and his subsequent failure to attain sufficient lift during the takeoff. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell 47G-5, 4 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1181032), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Bell 47G-5, 2 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=1181032), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Bell 47G-5, 3 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=1181032), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Aircraft capability: climb capability](https://openairdocs.org/ntsb-findings/01061010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Bell 47G-5, 1 case](https://openairdocs.org/ntsb-findings/01061010/cases.md?model=1181032), [All aircraft, 183 cases](https://openairdocs.org/ntsb-findings/01061010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Bell 47G-5, 4 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1181032), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Bell 47G-5, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=1181032), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot reported that during the agricultural operation he landed the helicopter into the wind to reload with fuel and agricultural chemicals. While the loader was mixing the chemicals, the pilot noted that the wind shifted to a tailwind condition. The pilot also noted that the rotor blades were dirty, but he forgot to clean them before departure. During the takeoff, the helicopter was unable to gain any lift and it started to sink back to the ground. The helicopter impacted the ground moments after takeoff with a slight nose low attitude which resulted in the skids collapsing and the main rotor blades contacting the tailboom. The pilot reported no preimpact mechanical malfunctions or failures with the airframe or the engine that would have precluded normal operation. ## Factual narrative The pilot reported that during the agricultural operation he landed the helicopter into the wind to reload with fuel and agricultural chemicals. While the loader was mixing the chemicals, the pilot noted that the wind shifted to a tailwind condition. The pilot also noted that the rotor blades were dirty, but he forgot to clean them before departure. During the takeoff, the helicopter was unable to gain any lift and it started to sink back to the ground. The helicopter impacted the ground moments after takeoff with a slight nose low attitude which resulted in the skids collapsing and the main rotor blades contacting the tailboom. The pilot reported no preimpact mechanical malfunctions or failures with the airframe or the engine that would have precluded normal operation. ## Aircraft - Registration: [N6260C](https://openairdocs.org/aircraft/N6260C), registered now, S/N 7952 (OpenAirDocs) - Reported make and model: BELL 47G (5) - Registry model: [Bell 47G-5](https://openairdocs.org/model/bell-47g-5) (registry code 1181032) (OpenAirDocs) - Category: Helicopter - Serial number: 7952 - Airframe hours: 1159 - Engines: LYCOMING VO435 265 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Agra Fly - Registered owner: Agra Fly - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, June 6, 2011, 69 hours before - Departed: KPTV, Porterville, CA - Destination: KPTV, Porterville, CA - Airport: KPTV, Porterville Municipal Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; injuries: none; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; medical: class 2, with waivers/limitations; last flight review May 15, 2011; seat: left; flight hours: 24,000 total, 3,500 in this make and model, 23,600 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 63 °F - Altimeter: 29.95 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 20110731017329A](https://openairdocs.org/incident/20110731017329A), Jul 31, 2011: Bell 47G-5, Pixley, CA, Substantial damage. Pilot attempted downwind takeoff from the top of a reloading truck after being reloaded during an aerial spraying operation. The helicopter settled to the… ## Other investigations on N6260C (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 LAX01LA093](https://openairdocs.org/ntsb/LAX01LA093), Feb 7, 2001: Bell 47G-5 (N6260C), Pixley, CA, substantial damage. Probable cause: A loss of control during takeoff due to the helicopter's heavy gross weight condition that exceeded its lifting capability. ## Docket (1 files) The files NTSB released with the investigation on September 1, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81564. 319 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 319 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40352886&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.