# NTSB CEN21LA363: Rotary RAF2000, Anahuac, TX, August 7, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: August 7, 2021, 11:15 local (16:15 UTC) - Place: Anahuac, TX - Coordinates: 29.763259, -94.660782 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.7633&lon=-94.6608&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 103657 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA363 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103657/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103657 - Page: https://openairdocs.org/ntsb/CEN21LA363 ## Probable cause The pilot’s incorrect trim system installation, which resulted in a loss of gyroplane control and impact with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) - [Flight control system: stabilizer control system](https://openairdocs.org/ntsb-findings/01022740): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [All aircraft, 13 cases](https://openairdocs.org/ntsb-findings/01022740/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Initial climb: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) ## Analysis The pilot had just installed a new trim system in the gyroplane and intended to complete a maintenance test flight. During the test flight, the pilot tried to adjust the trim, but nothing happened. The pilot actuated the trim switch again, and the gyroplane pitched up violently. The pilot attempted to override the trim switch but was unable to do so, and the gyroplane rapidly descended from 50 ft to ground impact. The pilot reported after the accident that a trim limit switch was not installed and that the trim system maintenance was probably done incorrectly. Thus, given the available evidence for this investigation, the pilot’s incorrect trim system maintenance likely caused the malfunction during flight and led to the pilot’s loss of gyroplane control. ## Factual narrative On August 7, 2021, about 1115 central daylight time, an unregistered Rotary Air Force RAF 2000 gyroplane sustained substantial damage when it was involved in an accident near Anahuac, Texas. The pilot was uninjured, and the passenger sustained minor injuries. The flight was operated as a Title 14 Code of Federal Regulations Part 91 test flight. The pilot reported that the test flight occurred after a new trim system was installed. The pilot stated that, during the test flight, he tried to adjust the trim, but nothing happened. He actuated the trim switch again, and the gyroplane responded with a “massive pitch up.” He attempted to override the trim switch but was unable to do so, and the gyroplane descended rapidly from 50 ft to ground impact. The figure below shows the gyroplane on its right side in a field. The fuselage, empennage, and rotor blades sustained substantial damage. Figure. Gyroplane wreckage in its resting location (source: Texas Department of Public Safety). The pilot stated that a trim limit switch was not installed, and that the trim system maintenance was “probably” done incorrectly, which is what caused the malfunction during flight. The maintenance logbooks were not made available during the investigation. ## Aircraft - Registration: UNREG (not matched to a registry record) - Reported make and model: ROTARY RAF2000 (STD) - Category: Gyroplane, amateur-built - Serial number: H2-99-10-436 - Year built: 1999 - Engines: Subaru EJ-22 reciprocating - Damage: Substantial damage - Flight: Flight test, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Airport: T00, Chambers County, runway 17, 1,900 × 300 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 76; injuries: none; private; airplane ratings: single-engine land; seat: left; restraint: 4-point; flight hours: 1,191 total, 15 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 90 °F, dew point 75 °F - Altimeter: 30.05 inHg - Observed at: KBMT, 30 nm away - METAR: KBMT 071610Z AUTO 21004KT 10SM CLR 32/24 A3005 RMK AO2 T03150238 ## Docket (4 files) The files NTSB released with the investigation on January 4, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103657. 7.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 4.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14070715&FileExtension=pdf&FileName=6120%20-%20pilot%202_Redacted-Rel.pdf - Pilot's statement (item 2, PDF, 2 pages, 177 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14824197&FileExtension=pdf&FileName=Pilot%20statement%20email%20to%20FAA_Redacted-Rel.pdf - Photos (item 3, PDF, 3 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14070190&FileExtension=pdf&FileName=Photos-Rel.pdf - Memorandum for record a�� investigation information (item 4, PDF, 1 page, 157 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14823955&FileExtension=pdf&FileName=Memorandum%20For%20Record%20-%20Accident%20details-Rel.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.