# NTSB CHI03LA172: Bell 206B, N79BH, Baxter, MN, June 20, 2003 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 20, 2003, 14:18 local (19:18 UTC) - Place: Baxter, MN - Coordinates: 46.397777, -94.137222 - Nearby events: https://openairdocs.org/map.md?lat=46.3978&lon=-94.1372&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor, 1 uninjured - Status: Completed, report November 25, 2003 - Report: Approved by Office Director - Parties: FAA- Minneapolis FSDO - NTSB case key (mKey): 57292 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI03LA172 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/57292/pdf - Page: https://openairdocs.org/ntsb/CHI03LA172 ## Probable cause The pilot's failure to maintain control of the helicopter due to a loss of tail rotor effectiveness. Factors contributing to this accident were the helicopter's low airspeed, low altitude, the crosswind, and the trees. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, hover - airspeed - low (contributing factor) - altitude - low (contributing factor) - tail rotor effectiveness - diminished (cause) - aircraft control - not maintained, pilot in command (cause) - autorotation - performed, pilot in command - weather condition - crosswind (contributing factor) - Forced landing, descent - emergency - autorotation - performed, pilot in command - In flight collision with object, descent - emergency - object - tree(s) (contributing factor) - In flight collision with terrain/water, descent - uncontrolled - terrain condition - ground ## Analysis The helicopter impacted trees during an autorotation following a loss of tail rotor authority. The pilot reported he was in a westbound hover about 300 feet above ground level, with a crosswind. The pilot noted the helicopter began to yaw slowly to the right and that his attempts to correct the yaw were unsuccessful. The pilot stated the yaw accelerated and the tail rotor lost effectiveness. The pilot reported he entered an autorotation after the helicopter had completed three or four rotations. The pilot noted the helicopter contacted trees and came to a stop in an upright position. An on-scene inspection of the helicopter confirmed engine and flight control continuity. A weather reporting station 3 miles to the southwest of the accident site reported the winds from 170 degrees at 14 knots, gusting to 21 knots. FAA Advisory Circular 90-95 states, "Loss of tail rotor effectiveness is a critical, low-speed aerodynamic flight characteristic which can result in a an uncommanded rapid yaw rate which does not subside of its own accord and, if not corrected, can result in the loss of aircraft control." The AC further states, "Any maneuver which requires the pilot to operate in a high-power, low-airspeed environment with a left crosswind or tailwind creates an environment where unanticipated right yaw may occur." ## Factual narrative On June 20, 2003, at 1418 central daylight time, a Bell 206B, N79BH, operated by Brainerd Helicopter Service, sustained substantial damage during an autorotation following a loss of tail rotor authority near Baxter, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The commercial pilot and one passenger reported minor injuries, and the other passenger was uninjured. The 14 CFR Part 91 business flight was operating without a flight plan. The local flight departed from Brainerd Lakes Regional Airport, Brainerd, Minnesota, at 1416. The pilot reported he lowered the helicopter's airspeed and proceeded downwind to the north at 300 feet above ground level. The pilot noted he brought the helicopter into a hover after turning to the west. The pilot stated the helicopter began a "slow yaw to the right," which he attempted to correct with left pedal. The pilot reported the pedal inputs, "did not have any results" and "there was no tail rotor authority." The pilot noted the helicopter rotated three or four times in a level attitude. The pilot stated he attempted to maintain a forward airspeed and correct the rotation with "major pedal adjustments." The pilot reported he initiated an autorotation to descend into a clearing. The pilot noted the helicopter contacted trees in a nose level position and came to a rest upright. A Federal Aviation Administration (FAA) airworthiness inspector conducted an on-scene examination of the helicopter. The examination confirmed engine and flight control continuity. A weather reporting station at Brainerd Lakes Regional Airport, 3 miles to the southwest of the accident site, reported the winds at 1453 from 170 degrees at 14 knots, gusting to 21 knots. FAA Advisory Circular (AC) 90-95 states, "Loss of tail rotor effectiveness is a critical, low-speed aerodynamic flight characteristic which can result in a an uncommanded rapid yaw rate which does not subside of its own accord and, if not corrected, can result in the loss of aircraft control." The AC further states, "Any maneuver which requires the pilot to operate in a high-power, low-airspeed environment with a left crosswind or tailwind creates an environment where unanticipated right yaw may occur." ## Aircraft - Registration: [N79BH](https://openairdocs.org/deregistered/N79BH-2018-01-09), registration cancelled 2018-01-09, S/N 2788, built 1979 (OpenAirDocs) - Reported make and model: Bell 206B - Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs) - Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 2788 - Airframe hours: 9214.8 - Engines: Rolls-Royce 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: Brainerd Helicopter Service - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, April 5, 2003, 77.2 hours before - Departed: BRD, Brainerd, MN ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 38; injuries: minor; commercial; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; last flight review March 28, 2002; seat: right; flight hours: 1,281 total, 373 in this make and model, 1,206 as pilot in command, 21 in the last 90 days, 21 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 14 knots, gusting 21 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 46 °F - Altimeter: 30.04 inHg - Observed at: BRD, 3 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 20030620013049A](https://openairdocs.org/incident/20030620013049A), Jun 20, 2003: Bell 206B, Baxter, MN, Substantial damage. (-23) Local photo flight with pilot and two passengers. Pilot was in 300 foot high-hover over wooded area adjacent to building construction site. Pilot stated… 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.