# NTSB DFW07LA197: Robinson Helicopter R22 Beta, N993KC, Fort Stockton, TX, September 12, 2007 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: September 12, 2007, 14:38 local (19:38 UTC) - Place: Fort Stockton, TX - Coordinates: 31.363889, -103.019447 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=31.3639&lon=-103.0194&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed, report December 24, 2008 - Report: Approved by Office Director - Parties: Federal Aviation Administration, FSDO - NTSB case key (mKey): 66657 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW07LA197 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66657/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=66657 - Page: https://openairdocs.org/ntsb/DFW07LA197 ## Probable cause The failure of the v-belt drive system to the main rotor for undetermined reasons. Contributing to the accident was insufficient altitude to perform a successful autorotation. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Rotor failure/malfunction, climb - to cruise - reason for occurrence undetermined (cause) - rotor drive system,main rotor drive belt - failure (cause) - Forced landing, descent - emergency - Hard landing, descent - emergency - aircraft performance,landing capability - low level (contributing factor) - aircraft handling - not successful, pilot in command (contributing factor) ## Analysis The single-engine helicopter experienced a hard landing after a malfunction of the belt drive system for the main rotor. The pilot had just taken off from a trailer and had transitioned to low level cruise flight when he heard a loud bang. The pilot cross-checked his engine instruments and observed the engine RPM was excessively high and the rotor RPM was below 80 percent, accompanied by the low rotor RPM warning. The pilot then initiated an autorotation and landed hard with near zero forward speed. The aircraft bounced backwards after initial impact and came to rest in the upright position. The on-scene investigation noted that one of the v-belts to the main rotor drive system had separated which caused the other belt to slip off the upper spindle. The reason for the separation could not be determined. ## Factual narrative On September 12, 2007 at 1438 central standard time N993KC, a Robinson R22 Beta helicopter, experienced a hard landing after a malfunction of the belt drive system for the main rotor. The pilot received serious injuries and his passenger received minor injuries as a result of a hard landing. The pilot had just taken off from a trailer and had climbed to about 50 feet above ground level to conduct a predator control mission about 10 miles northwest of Fort Stockton, Texas. The flight was conducted in visual meteorological conditions under 14 Code of Federal Regulations, Part 91. In an interview with the pilot, a Federal Aviation Administration (FAA) inspector stated that the pilot had just transitioned to a low level cruise after takeoff when he heard a loud bang and felt a vibration in the pedals. He observed the engine rpm was excessively high and noticed the rotor RPM was below 80 percent accompanied by the low rotor RPM warning. He then lowered the collective and searched for a location to make an emergency landing. The pilot then initiated an autorotation, was not able to recover the rotor RPM, and landed hard with near zero forward speed. The aircraft bounced backwards after initial impact and came to rest in the upright position. An FAA inspector conducted an on scene investigation and noted that one of the v-belts to the main rotor drive system had separated which caused the other belt to slip off the upper spindle. The pilot stated the clutch light was operating normally prior to takeoff. Weather reported at 1411 central daylight time at Fort Stockton (KFST), 10 miles north west of the accident site, was winds 110 degrees at 9 knots, 10 miles visibility, scattered clouds at 2100 feet and 2600 feet, temperature 24 degrees Celsius, dew point 18 degrees Celsius, and an altimeter reading of 30.11 inches of Mercury. ## Aircraft - Registration: [N993KC](https://openairdocs.org/deregistered/N993KC-2018-03-16), registration cancelled 2018-03-16, S/N 2926, built 1999 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER R22 BETA - Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 2926 - Airframe hours: 2114 - Engines: LYCOMING O&VO-360 SER 180 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Operator: Smith Helicopters Inc, doing business as Smith Helicopters, Inc - Registered owner: Smith Helicopters Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, February 8, 2007 - Departed: Fort Stockton, TX - Destination: Fort Stockton, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; injuries: serious; commercial, private; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review November 5, 2006; seat: right; flight hours: 13,967 total, 3,428 in this make and model, 31 in the last 90 days, 11 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 64 °F - Altimeter: 30.11 inHg - Observed at: KFST, 10 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 20070912020579A](https://openairdocs.org/incident/20070912020579A), Sep 12, 2007: Robsin R22BETA, Fort Stockton, TX, Substantial damage. (-23) On September 12, 2007, at approximately 1420 CDT, the pilot [privacy data omitted] experienced an increase in engine RPM immediately followed by a… ## Docket (7 files) The files NTSB released with the investigation on December 23, 2008, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=66657. 844 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 309 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467404&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photo 1 - Right Side (item 2, .PDF, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40305363&FileExtension=.PDF&FileName=Photo%201%20-%20Right%20Side-Master.PDF - Photo 2 - Rear View (item 3, .PDF, 112 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40305364&FileExtension=.PDF&FileName=Photo%202%20-%20Rear%20View-Master.PDF - Photo 3 - Pulley system and belts (item 4, .PDF, 77 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40305365&FileExtension=.PDF&FileName=Photo%203%20-%20Pulley%20system%20and%20belts-Master.PDF - Photo 4 - Belt separation (item 5, .PDF, 70 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40305366&FileExtension=.PDF&FileName=Photo%204%20-%20Belt%20separation-Master.PDF - Reports from Federal Agencies - FAA statement (item 6, .PDF, 27 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40305361&FileExtension=.PDF&FileName=Reports%20from%20Federal%20Agencies%20-%20FAA%20statement-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 7, .PDF, 126 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40306292&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Master.PDF 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.