Aviation Accident Summaries

Aviation Accident Summary CHI00FA020

COTTAGE GROVE, MN, USA

Aircraft #1

N565KS

Bell 206B

Analysis

The helicopter impacted terrain and was consumed by fire following a departure from cruise flight. Radar data indicated that the helicopter was proceeding on a heading of 103 degrees at an altitude of 1,300 feet msl and ground speed of 116 knots. Winds were from 280 degrees at 16 knots with gusts of 25 knots. Witnesses reported that the helicopter was proceeding eastbound at a low altitude and 'made a nose dive to the ground.' The main rotor blade and tail rotor assembly sustained damage consistent with a tail rotor strike in a nose high clockwise rotation. Examination of the engine and transmission did not reveal any mechanical anomalies.

Factual Information

HISTORY OF FLIGHT On November 1, 1999, at 1045 central standard time, a Bell 206B, N565KS, operated by Elmo Air Center, Incorporated, was destroyed on impact with terrain in Cottage Grove, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The CFR Part 91 positioning flight was not operating on a flight plan. The commercial pilot and commercial-rated pilot passenger were fatally injured. The flight departed South Saint Paul Municipal-Richard E. Fleming Field (SGS), South Saint Paul, Minnesota, at approximately 1040, en route to Austin Straubel International Airport (GRB), Greenbay, Wisconsin. A witness reported "the helicopter appeared to be traveling quite fast and as it traveled along horizontally and proceeded eastbound, it suddenly made a nose dive to the ground." A second witness reported "the helicopter appeared to be flying low, similar to that of a crop dusting plane. The witness described the descent of the helicopter as not a complete nosedive, but somewhat close to a nosedive." PERSONNEL INFORMATION The pilot was 33 years old and held a commercial pilot certificate with rotorcraft-helicopter, instrument-helicopter and airplane single engine land ratings. He received a second class medical with the limitation of "holder shall wear corrective lenses" on July 28, 1999. Logbook entries indicate that he accumulated a total flight time of 5,845.6 hours of which 3,531.4 hours were in helicopters. The passenger was 28 years old and held a commercial pilot certificate with a rotorcraft-helicopter rating. He received a second-class medical certificate with a limitation "holder must wear corrective lenses for distant vision" on April 12, 1999. He reported a total flight time of 206 hours at the time of application of the medical certificate. AIRCRAFT INFORMATION The helicopter, serial number 056, accumulated a total airframe time of 6,724.6 hours at a 100-hour inspection on October 15, 1999. The Allison 250-C20B engine, serial number CAE831659, accumulated total time of 5,376.9 hours at a 100-hour inspection October 15, 1999. METEOROLOGICAL INFORMATION At 1034, SGS reported winds from 280 degrees at 16 knots gusting 25 knots. WRECKAGE AND IMPACT INFORMATION The main wreckage area was located approximately 6 miles east of SGS in a corn stubble field with east-west rows. The magnetic heading of the aircraft was 014 degrees. Approximately 70 feet forward of the helicopter's nose, on a magnetic heading of 017 degrees, there were two holes with two parallel rectangular ground scars. Each ground scar had a magnetic heading of 207 degrees. The easternmost ground scar was 3 feet in length and 4 inches in width. The westernmost rectangular ground scar was 1 foot 6 inches in length and four inches in width. A distance of 7 feet 2 inches separated both ground scars. Two ground slash markings, 3 and 4 feet in length, were located between and to the east of the main wreckage and the two parallel ground scars. The cockpit section to the transmission was consumed by fire. Continuity of the transmission was established. A semicircular indentation was located approximately 20 inches from the tip of one of the main rotor blades. The indentation was of a diameter consistent with that of the tail rotor drive shaft, which was fractured and bent approximately 90 degrees. The tail rotor drive shaft exhibited a 45-degree fracture. The vertical stabilizer section was bent in the upward direction of approximately 30 degrees. The left horizontal stabilizer exhibited lateral compression wrinkles and the tail section aft of the horizontal stabilizer was bent to the right about 30 degrees. MEDICAL AND PATHOLOGICAL INFORMATION Federal Aviation Administration (FAA) toxicological test results for the pilot and passenger were negative for all substances tested. Autopsies of the pilot and passenger were conducted by the Ramsey County Medical Examiner's Office, Ramsey County, Minnesota. TEST AND RESEARCH Great circle distance from SGS to GRB was 210.3 nmi on a true heading of 94.4 degrees. A plot of radar data is included in this report. The radar data indicated the following: TIME ALTITUDE HEADING SPEED 1041:09.279 1300 88 127 1041:13.904 1300 86 127 1041:23.219 1300 91 127 1041:27.778 1300 97 125 1041:32.464 1300 101 122 1041:37.091 1300 106 119 1041:41.719 1200 103 116 There were no further radar track data reported after 1041:41.719. The engine was examined during a teardown at Rolls Royce Allison under the supervision of the FAA. The engine fuel control and governor were examined at Honeywell under the supervision of the FAA. Examination of the engine and engine accessories did not reveal any preimpact failures and nothing was found to indicate the engine was not capable of producing power. The manufacturer's reports of these examinations are included in this report. ADDITIONAL INFORMATION The FAA, Bell Helicopter, and Rolls Royce were parties to the investigation.

Probable Cause and Findings

Undetermined.

 

Source: NTSB Aviation Accident Database

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