# NTSB CHI08CA254: Bell 47G-3B, N47AH, Kenyon, MN, August 14, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 14, 2008, 10:45 local (15:45 UTC) - Place: Kenyon, MN - Coordinates: 44.320835, -92.874725 - Nearby events: https://openairdocs.org/map.md?lat=44.3208&lon=-92.8747&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Settling with power/vortex ring state](https://openairdocs.org/ntsb-events/244) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 26, 2008 - Report: Approved by Office Director - NTSB case key (mKey): 68761 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI08CA254 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68761/pdf - Page: https://openairdocs.org/ntsb/CHI08CA254 ## Probable cause The pilot's inadequate preflight planning which resulted in the helicopter settling with power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Planning/preparation: performance calculations](https://openairdocs.org/ntsb-findings/02061010): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell 47G-3B, 1 case](https://openairdocs.org/ntsb-findings/02061010/cases.md?model=1181026), [All aircraft, 114 cases](https://openairdocs.org/ntsb-findings/02061010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Settling with power/vortex ring state](https://openairdocs.org/ntsb-events/244) (defining event); cases with it: [Bell 47G-3B, 1 case](https://openairdocs.org/ntsb-events/244/sequence.md?model=1181026), [All aircraft, 52 cases](https://openairdocs.org/ntsb-events/244/sequence.md) - [Takeoff: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Bell 47G-3B, 6 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1181026), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported he had flown the helicopter on several aerial application flights earlier in the day, and that the humidity had increased as the weather cleared. He stated that the initial takeoff was normal, but that when he was about 100 yards from the support truck, the rotor rpm began to decay, and the helicopter settled into a soybean field. The spray boom caught in the crop, and the helicopter pitched forward, which resulted in the main rotor blades contacting the ground. The aft section of the tail boom, including the tail rotor, separated from the helicopter. The pilot reported there was no mechanical malfunction/failure with the helicopter. He did report that he should have decreased his load due to the weather conditions. ## Factual narrative On August 14, 2008, at 1045 central daylight time, a Bell helicopter 47G-3B, N47AH, collided with the terrain following a loss of control while taking off from a support truck in Kenyon, Minnesota. The pilot was not injured and the helicopter was substantially damaged. The aerial application flight was being operated under Title 14 Code of Federal Regulations Part 137. Visual meteorological conditions prevailed and no flight plan was filed. The local flight was originating at the time of the accident. The pilot reported he had flown several aerial application flights earler in the day and that the humidity had increased as the weather cleared. He stated that the initial takeoff was normal. The pilot stated that when he was about 100 yards from the support truck, the rotor rpm began to decay and the helicopter settled into a soybean field. The spray boom caught in the crop and the helicopter pitched forward which resulted in the main rotor blades contacting the ground. The aft section of the tailboom, including the tail rotor, separated from the helicopter. The pilot reported there was no mechanical malfunction/failure with the helicopter. He did report that he should have decreased his load due to the weather conditions. ## Aircraft - Registration: [N47AH](https://openairdocs.org/aircraft/N47AH), registered now, S/N 2645, built 1961 (OpenAirDocs) - Reported make and model: Bell 47G-3B - Registry model: [Bell 47G-3B](https://openairdocs.org/model/bell-47g-3b) (registry code 1181026) (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: 2645 - Engines: Lycoming 435A/F reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Scotts Helicopter Service, Inc. - Airworthiness certificate: Special, Restricted (Special) - Departed: Kenyon, MN ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; flight hours: 12,900 total, 3,000 in this make and model, 12,665 as pilot in command, 184 in the last 90 days, 56 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 280° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 64 °F - Altimeter: 29.96 inHg - Observed at: FBL ## 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 20080814844439A](https://openairdocs.org/incident/20080814844439A), Aug 14, 2008: Bell 47G3B, Kenyon, MN, Substantial damage. (-23) Pilot was performing aerial pesticide application in a Bell 47. He was about to begin his 8th field that day. The helicopter was positioned on a flatbed… ## Other investigations on N47AH (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 GAA17CA436](https://openairdocs.org/ntsb/GAA17CA436), Jul 24, 2017: Bell 47G 3B (N47AH), Toterville, IA, substantial damage. Probable cause: The pilot’s failure to maintain rotor rpm while maneuvering at low altitude with low airspeed and a tailwind. - [NTSB SEA98LA006](https://openairdocs.org/ntsb/SEA98LA006), Oct 19, 1997: Bell 47-G3B (N47AH), Winston, MT, substantial damage. Probable cause: Fuel starvation due to fuel flow restriction from a failed carburetor automatic mixture control device. Factors include night light conditions for the forced landing. 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.