# NTSB CEN23LA150: Helicopteres Guimbal Cabri G2, N372PA, Cahokia, IL, April 9, 2023 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: April 9, 2023, 08:45 local (13:45 UTC) - Place: Cahokia, IL - Coordinates: 38.570361, -90.155083 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.5704&lon=-90.1551&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration, St. Louis FSDO, Bureau d'Enquêtes et d'Analyses pour la sécurité de l'aviation civile - NTSB case key (mKey): 107038 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA150 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/107038/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=107038 - Page: https://openairdocs.org/ntsb/CEN23LA150 ## Probable cause The lack of proper attachment of the cyclic control that resulted in a loss of control during a landing approach and impact with terrain. Contributing to the accident was the improper maintenance performed. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Flight control system](https://openairdocs.org/ntsb-findings/01022700): Aircraft › Aircraft systems · Not specified (probable cause); cases with it: [Helicopteres Guimbal CABRI G2, 1 case](https://openairdocs.org/ntsb-findings/01022700/cases.md?model=9000001), [All aircraft, 65 cases](https://openairdocs.org/ntsb-findings/01022700/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Helicopteres Guimbal CABRI G2, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=9000001), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing-flare/touchdown: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Helicopteres Guimbal CABRI G2, 7 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=9000001), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing-flare/touchdown: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Helicopteres Guimbal CABRI G2, 6 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=9000001), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing-flare/touchdown: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Helicopteres Guimbal CABRI G2, 10 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=9000001), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The flight instructor stated that during an instructional flight he lost left cyclic control during an approach for landing. The student pilot’s right cyclic controls continued to function, and the flight instructor coached him on cyclic control inputs to maintain control of the helicopter. The student’s cyclic control became unresponsive to control inputs during the attempted landing and the helicopter impacted the ground resulting in substantial damage to the main rotor blades. Postaccident examination of the flight control system revealed that retaining hardware for the pins used to attach the left cyclic control were not installed. Maintenance personnel were unable to provided information regarding previous maintenance performed on the cyclic controls. The left cyclic control did not have any deformation/damage. ## Factual narrative On April 9, 2023, at 0845 central daylight time, a Helicopteres Guimbal Cabri G2, N372PA, was involved in an accident near Cahokia, Illinois. The helicopter sustained substantial damage. The flight instructor received minor injuries and the student pilot was uninjured. The helicopter was operated under Title 14 Code of Federal Regulations Part 91 as an instructional flight. The flight instructor stated that during the approach for landing at the departure airport, his left cyclic had “a little bit of play,” and the helicopter was not responding fully to his control inputs. He then completely lost cyclic control upon lining up with the taxiway of intended landing site. He stated that he still had collective and rudder control. The student pilot’s cyclic controls continued to function, and the flight instructor coached him on cyclic control inputs to maintain control of the helicopter, but the student pilot’s cyclic control then ceased to function. The helicopter impacted the ground during the attempted landing and sustained substantial damage to the main rotor blades. Postaccident examination of the flight control system revealed that the helicopter’s Illustrated Parts Catalog part #34 (Reference HG17-0545) - Pin and part #36 (Reference HG21-0803) – Safety Pin were found not inplace on the left cyclic control. Part #43.0 (Reference G41-41-300) – Pin Locker, part # 44 (Reference HG20-2036) – Bolt and part #7 (Reference HG12-0332) – Nut were not installed. Ideal Aviation was unable to a date when these parts were removed. There was no evidence indicating these parts were impacted by the crash. The left cyclic control did not have any deformation/damage. ## Aircraft - Registration: [N372PA](https://openairdocs.org/deregistered/N372PA-2024-12-28), registration cancelled 2024-12-28, S/N 1150, built 2016 (OpenAirDocs) - Reported make and model: HELICOPTERES GUIMBAL CABRI G2 - Registry model: [Helicopteres Guimbal CABRI G2](https://openairdocs.org/model/helicopteres-guimbal-cabri-g2) (registry code 9000001) (OpenAirDocs) - Registry engine: [Lycoming O-360-J2A](https://openairdocs.org/engine/lycoming-o-360-j2a) (registry code 42314, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 1150 - Year built: 2016 - Engines: Lycoming O-360 145 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Ideal Aviation - Registered owner: Rotor Leasing LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 7, 2023 - Destination: Same as departure - Airport: CPS, St Louis Downtown Airport, runway Taxiway A, 2,000 × 50 ft, concrete - Equipment: Electronic primary flight display, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 27; injuries: minor; flight instructor, private, commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review June 5, 2022; seat: left; restraint: 4-point; flight hours: 545 total, 542 in this make and model, 483 as pilot in command, 87 in the last 90 days, 40 in the last 30 days, 3 in the last 24 hours - Student pilot; age 41; injuries: none; private; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review July 2, 2010; seat: right; restraint: 4-point; flight hours: 131 total, 17 in this make and model, 34 as pilot in command, 17 in the last 90 days, 9 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 52 °F, dew point 30 °F - Altimeter: 30.40 inHg - Observed at: CPS ## 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 20230409008059A](https://openairdocs.org/incident/20230409008059A), Apr 9, 2023: Helicopteres Guimbal CABRI G2, Cahokia Heights, IL, Substantial damage. The helicopter departed the ramp after practicing two liftoffs and touchdowns. The helicopter received clearance from the tower to flight taxi to taxiway a to… ## Docket (6 files) The files NTSB released with the investigation on July 10, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=107038. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15377146&FileExtension=pdf&FileName=6120%20Master_Redacted-Rel.pdf - Memorandum of record - FAA (item 2, PDF, 2 pages, 72 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16647698&FileExtension=pdf&FileName=MOR-Rel.pdf - Record of examination (item 3, PDF, 1 page, 66 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16647913&FileExtension=pdf&FileName=Record%20of%20Examination-Rel.pdf - Illustrated parts catalog excerpt (item 4, PDF, 3 pages, 327 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16592760&FileExtension=pdf&FileName=IPC4%20(002)_Redacted-Rel.pdf - Maintenance records (item 5, PDF, 18 pages): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16598782&FileExtension=pdf&FileName=Maintenance%20Records%20Master_Redacted-Rel.pdf - Photos (item 6, PDF, 7 pages): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16598259&FileExtension=pdf&FileName=Photo%20Template-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.