# NTSB DEN01LA067: Robinson R22 Beta, N144MB, Buffalo, WY, March 11, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 11, 2001, 13:20 local (20:20 UTC) - Place: Buffalo, WY - Coordinates: 44.340576, -106.710746 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.3406&lon=-106.7107&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 19, 2001 - Report: Approved by Office Director - Parties: FAA, CASPER FSFO - NTSB case key (mKey): 51890 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN01LA067 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/51890/pdf - Page: https://openairdocs.org/ntsb/DEN01LA067 ## Probable cause failure of the rotor drive system clutch assembly which rendered the aircraft uncontrollable. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Rotor failure/malfunction, cruise - normal - aircraft control - not possible, pilot in command (contributing factor) - rotor drive system,clutch assembly - failure,total (cause) - Forced landing, descent - uncontrolled - autorotation - not possible, pilot in command - Hard landing, descent - uncontrolled ## Analysis Approximately 20 minutes after takeoff on a cross-country flight, the pilot noticed the clutch light was on and he smelled burning rubber. The pilot conducted a power on autorotation and at approximately 50 feet above the ground, he heard a loud "pop" and the aircraft "dropped" to the ground, skidded about 15 feet, and rolled over on its side when a skid collapsed. Inspection revealed that the upper clutch actuator bearing had failed. All required inspections regarding the bearing assembly had been performed. Procedures used by the manufacturer require both the pilot and mechanic to listen for unusual bearing noise at specific intervals. ## Factual narrative On March 11, 2001, at 1320 mountain standard time, a Robinson R22 Beta, N144MB, sustained substantial damage during a forced landing approximately 20 miles east of Buffalo, Wyoming. The private pilot, the sole occupant, was not injured. The flight was a cross-country flight from Gillette, Wyoming, to Bozeman, Montana, and was being flown under Title 14 CFR Part 91. No flight plan was filed, and visual meteorological conditions prevailed. The flight departed Gillette Wyoming, at 1300. According to the pilot, he was in cruise flight about 2,200 feet above the ground when the clutch light came on and he smelled burning rubber. The pilot reportedly did a power on autorotation and at approximately 50 feet above the ground, he heard a loud "pop" and the aircraft "dropped" to the ground and skidded about 15 feet. The right skid broke off and the aircraft rolled on its right side. The fuselage and rotor system suffered substantial damage. Examination of the helicopter provided evidence of a failure of the upper actuator bearing, part number A-184. The bearing assembly is pressed onto the clutch shaft and is used as a point of attachment for one end of the V-belt tightening actuator. The other end is attached to a pulley, which presses against the V-belts when the actuator is activated. The actuator is electrically actuated to extend, which tightens the V-belts and enables the engine to supply power to the drive train. The actuator/bearing assembly requires inspection during the 100 hour inspection. An inspection was performed approximately 35 hours prior to the accident. The method of inspection requires the mechanic to listen to the assembly during varying speed ranges to detect unusual bearing noise. In addition, a Robinson Safety Notice (#28), requires the pilot to listen during start up and shut down for unusual noises in the upper and lower clutch actuator bearings. According to the safety notice, a failing bearing will produce a whine, rumble, growl, or siren sound. The aircraft was equipped with Teletemp indicator tapes (part numbers 110-2 and 110-4). The tapes are used to track changes in operating temperature. The status of the tapes was checked 1 hour prior to the failure for any trend change. No change was found. ## Aircraft - Registration: [N144MB](https://openairdocs.org/deregistered/N144MB-2001-06-14), registration cancelled 2001-06-14, S/N 1449 (OpenAirDocs) - Reported make and model: Robinson R22 BETA - Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs) - Category: Helicopter - Serial number: 1449 - Airframe hours: 1140 - Engines: Lycoming O-320 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 17, 2000, 35 hours before - Departed: GCC, GILLETTE, WY - Destination: BZN, BOZEMAN, MT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: none; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; last flight review January 21, 2001; seat: right; flight hours: 160 total, 35 in this make and model, 75 as pilot in command, 49 in the last 90 days, 2 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 315° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none ## 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 20010311003979A](https://openairdocs.org/incident/20010311003979A), Mar 11, 2001: Robsin R22BETA, Buffalo, WY, No damage. (-23) While flying at 2,000 AGL from gillette to Buffalo, WY, the clutch light came on and the pilot smelled burning rubber. The pilot performed a power on… 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.