# NTSB CHI01LA243: Bell 47G-2, N986B, Wheeler, WI, July 26, 2001 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: July 26, 2001, 09:40 local (14:40 UTC) - Place: Wheeler, WI - Coordinates: 45.039333, -91.900909 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.0393&lon=-91.9009&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report April 1, 2003 - Report: Approved by Office Director - Parties: Federal Aviation Administration - Minneapolis FSDO - NTSB case key (mKey): 52905 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI01LA243 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/52905/pdf - Page: https://openairdocs.org/ntsb/CHI01LA243 ## Probable cause The pilot not maintaining altitude/clearance from the power transmission line. A factor to the accident was the power transmission line. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, maneuvering - aerial application - object - wire,transmission (contributing factor) - altitude/clearance - not maintained, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled - Fire, other ## Analysis While maneuvering during an aerial application flight, the helicopter impacted a power transmission line and subsequently impacted the terrain. The pre-impact height of the power transmission line was approximated to be 42 feet. The tailboom assembly, including the tail-rotor, was found approximately 125 feet from the main wreckage. No anomalies were found during the post-accident inspection that could be associated with any pre-impact condition. ## Factual narrative HISTORY OF FLIGHT On July 26, 2001, at 0940 central daylight time, a Bell 47G-2, N986B, was substantially damaged during an in-flight collision with power lines and subsequent collision with the terrain near Wheeler, Wisconsin. Visual meteorological conditions prevailed at the time of the accident. The aerial application flight was operating under the provisions of 14 CFR Part 137 and was not on a flight plan. The pilot, the sole occupant, was fatally injured. The local flight departed at 0930. According to a witness to the accident, the helicopter approached from the east and attempted to clear some power transmission lines and impacted the top wire, subsequently impacting the terrain. The witness reported that a fire started subsequent to the helicopter impacting the terrain. Another witness reported hearing a power line pole breaking and saw the helicopter impact the terrain. The witness stated that a fire started after the helicopter impacted the terrain. The witness statements are appended to this factual report. PERSONNEL INFORMATION According to Federal Aviation Administration (FAA) and Transport Canada records, the pilot was the holder of commercial pilot certificate with a rating for helicopters. The pilot also held an airline transport pilot certificate and was certified for single-engine land/sea airplanes and multiengine land airplanes. The pilot was instrument rated. According to FAA records the pilot completed his last aviation medical examination on May 9, 2001, and was issued a second-class medical certificate with the limitation, "Must wear corrective lenses and possess glasses for near and intermediate vision." The pilot was reported to have had accumulated a total time of 9,839.2 hours as pilot-in-command (PIC), of which 5,889.4 hours were in helicopters and 3,949.8 hours were in airplanes. The pilot had accumulated a total of 500 hours as PIC in the accident helicopter make and model. The pilot had flown 75 hours during the last 90 days, all of which were in the same make and model as the accident helicopter. The pilot had flown 65 hours during the last 30 days and 8 hours during the last 24 hours. AIRCRAFT INFORMATION The helicopter was a Bell 47G-2, serial number 1399. At the time of the accident, the helicopter had accumulated 9,752.3 hours since new. The helicopter's last annual inspection was on May 1, 2001, and the helicopter had accumulated approximately 10 hours since the last inspection. The engine was a 265 horsepower Lycoming VO-435-A1F, serial number L-2733-52. At the time of the accident, the engine had accumulated 1,093.0 hours since the last overhaul. METEOROLOGICAL INFORMATION A weather reporting station, located at the Chippewa Valley Regional Airport, approximately 22 nautical miles southeast of the accident site, reported the weather at 0956 as: Wind: 090 degrees magnetic at 9 knots Visibility: 10 statute miles Sky Condition: Sky Clear Temperature: 20 degrees Celsius Dew Point: 09 degrees Celsius Pressure: 30.25 inches of mercury WRECKAGE AND IMPACT INFORMATION The wreckage was located in an agricultural field and a downed power transmission line was found near the accident site. The power transmission lines ran parallel to a north/south-orientated road that was adjacent to the agricultural field in which the main wreckage was located. The pre-impact height of the power line was reported to be 42 feet. The helicopter's tailboom assembly, including the tail-rotor, was found approximately 75 feet west of the road. The main wreckage was found approximately 125 feet from the tailboom assembly, or 200 feet west of the road. During a post-accident inspection of the aircraft, no anomalies were found with the helicopter, or its related systems, that could be associated with any pre-impact condition. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot at the Sacred Heart Hospital, Eau Claire, Wisconsin, on July 26, 2001. A Forensic Toxicology Fatal Accident Report was prepared by the FAA Civil Aeromedical Institute, Oklahoma City, Oklahoma, for the pilot. The toxicology results for the pilot were: * No Carbon Monoxide detected in Blood * No Cyanide detected in Blood * No Ethanol detected in Vitreous * 1.549 (ug/ml, ug/g) Acetaminophen detected in Blood SURVIVAL ASPECTS The Dunn County Medical Examiner reported that there was a helmet found at the accident site, but the pilot was not wearing the helmet at the time of the accident. The Medical Examiner reported that the pilot was not wearing the available shoulder harness at the time of the accident, but was wearing the lap belt. The inboard lap belt attachment point was found pulled loose from the supporting aircraft structure. ## Aircraft - Registration: N986B (not matched to a registry record) - Reported make and model: Bell 47G-2 - Category: Helicopter - Serial number: 1399 - Airframe hours: 9752.3 - Engines: Lycoming VO-435-A1F 265 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Aerial application, Part 137 - Registered owner: Scott's Helicopter Services, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, May 1, 2001, 10 hours before - Departed: Wheeler, WI - Destination: Wheeler, WI ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: fatal; airline transport, commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review July 24, 2000; seat: front; toxicology performed; flight hours: 9,839 as pilot in command, 75 in the last 90 days, 65 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 48 °F - Altimeter: 30.25 inHg - Observed at: EAU, 22 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 20010726019339A](https://openairdocs.org/incident/20010726019339A), Jul 26, 2001: Bell 47G2, Wheeler, WI, No damage. (.19) On July 26, 2001, at 0940 central daylight time, a Bell 47G-2, N986B, was substantially damaged during an in-flight collision with power lines and… 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.