# NTSB CHI96LA223: Bell TH-13T, N96161, Mandan, ND, June 30, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 30, 1996, 13:20 local (18:20 UTC) - Place: Mandan, ND - Coordinates: 46.820358, -100.880111 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.8204&lon=-100.8801&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 19, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 10294 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI96LA223 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10294/pdf - Page: https://openairdocs.org/ntsb/CHI96LA223 ## Probable cause the pilot's failure to maintain clearance from known transmission lines. A factor relating to this accident was the sunglare which hindered the pilot's ability to see the transmission lines. ## 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 - light condition - sunglare (contributing factor) - clearance - not maintained, pilot in command (cause) - object - wire,transmission ## Analysis The pilot was spot spraying pasture land with pesticide. He turned into the sun heading east to follow a ravine. The pilot stated the sun was glaring off the bubble and he was unable to see the power lines until he was too close. When the pilot did see the power lines he 'pulled back and to the left to avoid them.' The helicopter's lower outside cabin struck the power lines and the helicopter settled to the ground tail first. ## Factual narrative On June 30, 1996, at 1320 central daylight time, a Bell TH-13T, N96161, operated by a commercial pilot, sustained substantial damage when while performing an aerial application, 18 miles northwest of Mandan, North Dakota, it struck some high line utility wires. The helicopter subsequently impacted the terrain. Visual meteorological conditions prevailed at the time of the accident. The aerial application flight was being conducted under 14 CFR Part 137. No flight plan was on file, and the pilot reported no injuries. The local flight originated at Mandan, North Dakota. In his written statement, the pilot said he was spot spraying pasture land with pesticide when he "turned into the sun heading east to follow a ravine. The sun was just right in the sky and was glaring off my bubble were I could not see the power lines until I was too close." When the pilot did see the power lines he "pulled back and to the left to avoid them." The helicopter's lower outside cabin struck the lines and the helicopter "went into the ground tail first." The Federal Aviation Administration (FAA) inspector who examined the wreckage at the site found the helicopter resting in the bottom of a ravine, beneath the power lines, oriented on a 270 degree heading. The cockpit bubble windscreen had separated from the frame and was broken. The aircraft frame which formed the cockpit was broken in several places. The pilot's seat was undamaged. The tail boom had broken at mid-span. The aft section of the boom and tail rotor was resting 40 feet south of the main wreckage. The boom exhibited upward bending at the points where it broke. Both tail rotor blades showed cuts in the leading edges at approximately mid-span. The forward frame, which held the engine and transmission, was twisted and bent. Both main rotor blades showed cuts on the inboard leading edges, approximately 5 feet outboard of the hub. There were also cuts on the blades' leading edges 3 feet inboard from the tips. Flight control continuity was established. No anomalies with the engine, engine controls or transmission were found. ## Aircraft - Registration: [N96161](https://openairdocs.org/aircraft/N96161), registered now, S/N 3547 (OpenAirDocs) - Reported make and model: Bell TH-13T - Registry model: [Bell TH-13T](https://openairdocs.org/model/bell-th-13t) (registry code 1180813) (OpenAirDocs) - Category: Helicopter - Serial number: 3547 - Airframe hours: 14076 - Engines: Lycoming VO-435-A1F 275 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Northern Helicopter, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, June 1, 1996, 37 hours before ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 500 total, 270 in this make and model, 400 as pilot in command, 50 in the last 90 days, 45 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Dawn - Wind: 260° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 43 °F - Altimeter: 30.00 inHg - Observed at: BIS, 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 19960630015639A](https://openairdocs.org/incident/19960630015639A), Jun 30, 1996: Bell TH13T, Mandan, ND, Destroyed. Helicopter struck high line utility wires. (-23) pilot was conducting aerial spraying of pesticide on open pasture. He finished spraying pasture area and was… 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.