# Main rotor control - Type: NTSB finding subsection - Path: [Aircraft](https://openairdocs.org/ntsb-findings/01) › [Aircraft propeller/rotor](https://openairdocs.org/ntsb-findings/0104) › [Rotorcraft flight control](https://openairdocs.org/ntsb-findings/010467) › Main rotor control - NTSB code: 01046710 - Cases: 28 - In the probable cause: 27 - Fatal cases: 6 - All cases: https://openairdocs.org/ntsb-findings/01046710/cases.md - Cases with it in the probable cause: https://openairdocs.org/ntsb-findings/01046710/cases.md?cause=1 - Page: https://openairdocs.org/ntsb-findings/01046710 ## Cases per year (in the probable cause / all) - 2008: 2 / 3 - 2009: 2 / 2 - 2010: 1 / 1 - 2011: 1 / 1 - 2012: 1 / 1 - 2015: 5 / 5 - 2016: 3 / 3 - 2017: 4 / 4 - 2018: 1 / 1 - 2019: 1 / 1 - 2022: 2 / 2 - 2023: 2 / 2 - 2024: 2 / 2 ## Defining events in these cases - [Hard landing](https://openairdocs.org/ntsb-events/092): 6 cases - [Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333): 5 cases - [Loss of control in flight](https://openairdocs.org/ntsb-events/240): 5 cases - [Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330): 3 cases - [Loss of control on ground](https://openairdocs.org/ntsb-events/230): 3 cases - [Miscellaneous/other](https://openairdocs.org/ntsb-events/900): 2 cases - [External load event (Rotorcraft)](https://openairdocs.org/ntsb-events/480): 1 cases - [Electrical system malf/failure](https://openairdocs.org/ntsb-events/332): 1 cases - [Mast bumping](https://openairdocs.org/ntsb-events/245): 1 cases - [Abnormal runway contact](https://openairdocs.org/ntsb-events/090): 1 cases ## Aircraft models (registry) - [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta): 4 cases - [Bell 206B](https://openairdocs.org/model/bell-206b): 2 cases - [Williams Helicopter UH-1H](https://openairdocs.org/model/williams-helicopter-uh-1h): 1 cases - [Aerospatiale SA315B](https://openairdocs.org/model/aerospatiale-sa315b): 1 cases - [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii): 1 cases - [Robinson Helicopter R44](https://openairdocs.org/model/robinson-helicopter-r44): 1 cases - [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d): 1 cases - [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e): 1 cases - [Enstrom F280](https://openairdocs.org/model/enstrom-f280): 1 cases - [Enstrom Helicopter 280C](https://openairdocs.org/model/enstrom-helicopter-280c): 1 cases ## Other findings in the same cases - [Aircraft control](https://openairdocs.org/ntsb-findings/02063040) (Personnel issues): 9 cases - [Use of equip/system](https://openairdocs.org/ntsb-findings/02063015) (Personnel issues): 7 cases - [Prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052) (Aircraft): 7 cases - [Incorrect action performance](https://openairdocs.org/ntsb-findings/02041015) (Personnel issues): 5 cases - [Not determined, general](https://openairdocs.org/ntsb-findings/05000000) (Not determined): 2 cases - [Scheduled/routine inspection](https://openairdocs.org/ntsb-findings/02061520) (Personnel issues): 2 cases - [Preflight inspection](https://openairdocs.org/ntsb-findings/02061510) (Personnel issues): 2 cases - [Monitoring other person](https://openairdocs.org/ntsb-findings/02021535) (Personnel issues): 2 cases - [Main rotor blade system](https://openairdocs.org/ntsb-findings/01046210) (Aircraft): 2 cases - [Equipment manufacture](https://openairdocs.org/ntsb-findings/04013010) (Organizational issues): 1 cases ## Newest cases - [NTSB CEN24FA248](https://openairdocs.org/ntsb/CEN24FA248), Jul 5, 2024: Rotorway Scorpion 133 (N51017), Andale, KS, destroyed, 1 fatal. Probable cause: The pilot’s abrupt control inputs, which resulted in a low-G condition, main rotor mast bumping, and subsequent severing of the tailboom by the main rotor blades. - [NTSB WPR24LA134](https://openairdocs.org/ntsb/WPR24LA134), Apr 23, 2024: Bell 206L-3 (N17592), Tracy, CA, substantial damage. Probable cause: A loss of collective control authority due to fatigue failure of the collective servo cylinder extension arms from corrosion pitting. - [NTSB CEN23LA199](https://openairdocs.org/ntsb/CEN23LA199), May 23, 2023: Bell Helicopter Textron Canada 407 (N451PH), Abbeville, LA, substantial damage. Probable cause: The pilot’s failure to maintain proper helicopter control during autorotation that resulted in an abnormal ground contact which caused the subsequent main rotor strike on the tail boom that severed… - [NTSB CEN23FA183](https://openairdocs.org/ntsb/CEN23FA183), May 14, 2023: Robinson R22 Beta (N40506), Brady, TX, incident, substantial damage, 1 fatal. Probable cause: The non-certificated pilot’s failure to ensure the collective friction control was adequately engaged during an on-ground engine run, which resulted in the helicopter inadvertently becoming airborne.… - [NTSB ERA23FA070](https://openairdocs.org/ntsb/ERA23FA070), Nov 22, 2022: Robinson Helicopter R44 (N7094J), Charlotte, NC, substantial damage, 2 fatal. Probable cause: The inadequate inspections of the forward left control rod end attachment hardware to the stationary swashplate by the pilot and by maintenance personnel, resulting in an eventual loosening and… - [NTSB CEN22LA430](https://openairdocs.org/ntsb/CEN22LA430), Sep 24, 2022: Agusta AW139 (N811TA), Houma, LA, substantial damage. Probable cause: The inflight loss of collective control of the helicopter due to thermal damage of a collective control torque tube that abraded with misrouted electrical wiring, which resulted in an electrical… - [NTSB CEN20LA037](https://openairdocs.org/ntsb/CEN20LA037), Dec 19, 2019: Robinson R22 (N695AP), Beeville, TX, substantial damage. Probable cause: The solo student pilot's improper cyclic input during takeoff, which resulted in dynamic rollover. - [NTSB ERA19FA034](https://openairdocs.org/ntsb/ERA19FA034), Oct 30, 2018: Autogyro Cavalon (N198LT), Sebring, FL, destroyed, 2 fatal. Probable cause: The pilot's improper decision to operate the gyroplane in an unairworthy condition, which resulted in the cyclic pitch control disconnecting in flight. Contributing was the pilot's inability to… - [NTSB GAA18CA086](https://openairdocs.org/ntsb/GAA18CA086), Dec 17, 2017: Halley KFT Apollo (N15LU), North Las Vegas, NV, substantial damage. Probable cause: The pilot’s failure to stop the main rotor rotation before taxiing the gyroplane in gusting wind conditions, resulting in the main rotor striking the empennage. - [NTSB WPR18LA004](https://openairdocs.org/ntsb/WPR18LA004), Oct 13, 2017: Western International Avia UH 1H (N247PV), Arbuckle, CA, substantial damage. Probable cause: A collective control malfunction for reasons that could not be determined. NTSB has coded findings and defining events since 2008; earlier cases used its older occurrence and cause codes and aren't counted. Findings: https://openairdocs.org/ntsb-findings.md. Defining events: https://openairdocs.org/ntsb-events.md. Phases of flight: https://openairdocs.org/ntsb-phases.md. Every investigation, filtered by finding, event, phase, state, year or model: https://openairdocs.org/ntsb.md (for example ?state=MI&fatal=1). NTSB's definitions: Accident and incident, 49 CFR 830.2 (https://www.ecfr.gov/current/title-49/subtitle-B/chapter-VIII/part-830/subpart-A/section-830.2), CICTT occurrence categories (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/OccurrenceCategoryDefinitions.pdf), CICTT phases of flight (PDF) (https://www.ntsb.gov/safety/data/Documents/datafiles/PhaseofFlightDefinitions.pdf), and NTSB coding manual, before 2008 (PDF) (https://www.ntsb.gov/GILS/Documents/codman.pdf). NTSB publishes no definitions for its findings, only their names. --- 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.