# NTSB DEN07CA013: Robinson R22 Beta, N224VR, Monticello, UT, October 16, 2006 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: October 16, 2006, 12:10 local (18:10 UTC) - Place: Monticello, UT - Coordinates: 38.09111, -109.089447 - Nearby events: https://openairdocs.org/map.md?lat=38.0911&lon=-109.0894&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 31, 2007 - Report: Approved by Office Director - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 64774 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN07CA013 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/64774/pdf - Page: https://openairdocs.org/ntsb/DEN07CA013 ## Probable cause an airframe vibration for reasons undetermined, resulting in the pilot performing a precautionary landing, and obstacle clearance not possible. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Miscellaneous/other, cruise - normal - airframe - vibration - reason for occurrence undetermined (cause) - In flight collision with object, landing - flare/touchdown - precautionary landing - initiated, pilot in command - autorotation - attempted, pilot in command - clearance - not possible, pilot in command (cause) - object - tree(s) - terrain condition - mountainous/hilly ## Analysis The pilot said he was cruising at 8,500 feet msl (mean sea level) and at 65 KIAS (knots indicated airspeed) when he experienced a "slight yaw oscillation." He decided to make a precautionary landing and initiated a descent. The oscillations increased to about one yaw per second. Before reaching the selected landing site, the "low-rotor RPM horn/light activated. When the pilot lowered the collective control to recover, he got an engine and rotor overspeed indication of 110 per cent. The pilot made a 180-degree turn and autorotated from 800 feet agl. The helicopter landed on rocky terrain, surrounded by pinon and juniper trees. Main and tail rotor and tail rotor blades struck the trees, separating the tail rotor blades and gearbox from the tail boom. According to the helicopter manufacturer, nothing was found that would explain the oscillations described by the pilot, or why the low-rotor RPM horn/light activated. ## Factual narrative On October 16, 2006, approximately 1210 mountain daylight time, a Robinson R22BETA, N224VR, registered to and piloted by an airline transport certificated pilot, was substantially damaged when the helicopter struck some scrub trees and terrain following uncontrollable yaw oscillations while in cruise flight approximately 18 miles northeast of Monticello, Utah. Visual meteorological conditions prevailed at the time of the accident. The business flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot, the sole occupant aboard, was not injured. The local flight originated at Dove Creek, Colorado, approximately 1150, and was en route to Lisbon Valley, Utah. According to the pilot's accident report and a verbal statement he gave to an FAA inspector, he was cruising at 8,500 feet msl (mean sea level) and at 65 KIAS (knots indicated airspeed) when he experienced a "slight yaw oscillation." The pilot decided to make a precautionary landing and initiated a descent. The oscillations increased to about one yaw per second. Before reaching the selected landing site, the "low-rotor RPM horn/light activated. When the pilot lowered the collective control to recover, he got an engine and rotor overspeed indication of 110 per cent. The pilot made a 180-degree turn and autorotated from 800 feet agl. The helicopter landed on rocky terrain, surrounded by pinon and juniper trees. Post-accident examination revealed the main rotor and tail rotor blades had struck trees. The tail rotor blades and gearbox separated from the tail boom. According to a Robinson Helicopters repairman, he had found nothing that would explain the oscillations described by the pilot, or why the low-rotor RPM horn/light activated. ## Aircraft - Registration: [N224VR](https://openairdocs.org/aircraft/N224VR), registered now, S/N 3038, built 2000 (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) - Registry engine: [Lycoming O-360 series](https://openairdocs.org/engine/lycoming-o-360-series) (registry code 41575, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 3038 - Airframe hours: 1472 - Engines: Lycoming O-360-J2A 145 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: Cady L. Johnson - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 1, 2005, 15 hours before - Departed: 8V6, Dove Creek, CO - Destination: NONE, Lisbon Valley, UT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; injuries: none; flight instructor, airline transport, private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review December 1, 2005; seat: right; flight hours: 3,832 total, 1,143 in this make and model, 3,641 as pilot in command, 7 in the last 90 days, 7 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 40 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 20061016022539A](https://openairdocs.org/incident/20061016022539A), Oct 16, 2006: Robsin R22BETA, Montrose, UT, Substantial damage. (-23) Pilot experienced yaw oscillation approximately 15 minutes into the flight. Pilot began descending for a precautionary landing but before he reached the… 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.