# NTSB CEN24LA013: Magni M24, N90HM, Mount Sterling, IL, October 16, 2023 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: October 16, 2023, 11:30 local (16:30 UTC) - Place: Mount Sterling, IL - Coordinates: 39.986285, -90.803982 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.9863&lon=-90.8040&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern downwind: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report October 22, 2025 - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Rotech Flight Safety, Inc, FAA-FSDO, ANSV, Magni Gyro SRL - NTSB case key (mKey): 193246 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN24LA013 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193246/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=193246 - Page: https://openairdocs.org/ntsb/CEN24LA013 ## Probable cause The pilot’s failure to maintain gyroplane control on the downwind leg, which resulted in impact with terrain. Contributing to the accident was the pilot’s distraction. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Main rotor system](https://openairdocs.org/ntsb-findings/01046200): Aircraft › Aircraft propeller/rotor · Incorrect use/operation (probable cause); cases with it: [Henry K Snow MAGNI M-24, 1 case](https://openairdocs.org/ntsb-findings/01046200/cases.md?model=05639E6), [All aircraft, 25 cases](https://openairdocs.org/ntsb-findings/01046200/cases.md) - [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Henry K Snow MAGNI M-24, 1 case](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=05639E6), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Henry K Snow MAGNI M-24, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=05639E6), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Attention/monitoring: task monitoring/vigilance](https://openairdocs.org/ntsb-findings/02021520): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Henry K Snow MAGNI M-24, 1 case](https://openairdocs.org/ntsb-findings/02021520/cases.md?model=05639E6), [All aircraft, 330 cases](https://openairdocs.org/ntsb-findings/02021520/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Henry K Snow MAGNI M-24, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=05639E6), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern downwind: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Henry K Snow MAGNI M-24, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=05639E6), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) ## Analysis The pilot reported that, while on the downwind leg of the traffic pattern, he was distracted while looking for other traffic in the pattern when he noticed that his airspeed had decayed to 37 mph, below the aircraft flight manual’s recommended traffic pattern airspeed of 65 mph. The pilot attempted to correct by increasing engine throttle but subsequently lost control. The gyroplane impacted terrain while in the left downwind leg, which resulted in substantial damage to the main rotor system and empennage. Postaccident examination of the gyroplane revealed no preaccident mechanical failures or malfunctions that would have precluded normal operation. Based on the available information, the pilot likely unloaded the rotor blades inadvertently, known as buntover, when he applied engine throttle to correct for the decaying airspeed. The sudden throttle application caused the gyroplane to abruptly pitch forward and tumble. The FAA Rotorcraft Flying Handbook notes that, in most cases, the proper recovery procedure for the condition is to immediately remove power and load the rotor blades. ## Factual narrative On October 16, 2023, about 1130 central daylight time, a Magni M24 gyroplane, N90HM, was substantially damaged when it was involved in an accident near Mount Sterling, Illinois. The pilot was not injured. The gyroplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The pilot reported that the gyroplane was on downwind for runway 36 at the Mount Sterling Municipal Airport (I63), when he noticed that his airspeed had decayed to 37 mph, below the recommended traffic pattern airspeed of 65 mph. He reported that his airspeed had decayed while his attention was diverted looking for other traffic. The pilot attempted to correct by increasing engine throttle but subsequently lost control. The gyroplane impacted terrain in the left downwind, which resulted in substantial damage to the main rotor system and empennage. During the recovery of the gyroplane, the smell of automotive fuel was present with soil discoloration around the area of the fuel cap. Postaccident examination revealed no preaccident mechanical failures or malfunctions with the gyroplane that would have precluded normal operation. The engine was successfully operated during the examination. The rotor pitch trim actuator arm was observed to be 2 inches from the actuator, which corresponds to a pitch trim setting of about 65 mph. The gyroplane flight manual recommends an airspeed of 65 mph during the traffic pattern when preparing to land. The FAA Rotorcraft Flying Handbook (FAA-H-8083-21), Section 21-3, states that, “If rotor force is rapidly removed, some gyroplanes have a tendency to pitch forward abruptly. This is often referred to as a forward tumble, buntover, or power pushover.” Referring to the recovery procedure, it notes that, “In most cases, you need to remove power and load the rotor blades.” ## Aircraft - Registration: [N90HM](https://openairdocs.org/aircraft/N90HM), registered now, S/N 24169824, built 2020 (OpenAirDocs) - Reported make and model: MAGNI M24 - Registry model: [Henry K Snow MAGNI M-24](https://openairdocs.org/model/henry-k-snow-magni-m-24) (registry code 05639E6) (OpenAirDocs) - Registry engine: [Rotax 914UL](https://openairdocs.org/engine/rotax-914ul) (registry code 55553, 4 cycle) (OpenAirDocs) - Category: Gyroplane, amateur-built - Serial number: 24169824 - Year built: 2020 - Airframe hours: 238 - Engines: Rotax 914UL 114 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental light sport (Special) - Last inspection: 100 hour, June 9, 2023 - Destination: Same as departure - Airport: I63, Mount Sterling Municpal ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: none; sport pilot; medical: sport pilot; last flight review September 24, 2023; seat: left; restraint: lap only; flight hours: 371 total, 215 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 320° at 6 knots - Visibility: 10 statute miles - Temperature: 55 °F, dew point 45 °F - Altimeter: 30.16 inHg - Observed at: KUIN, 18 nm away - METAR: KUIN 161654Z AUTO 32006KT 10SM FEW024 13/07 A3016 RMK AO2 SLP214 T01330067 $= ## 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 20231016017539A](https://openairdocs.org/incident/20231016017539A), Oct 16, 2023: Henry K Snow MAGNI M-24, Mount Sterling, IL, Substantial damage. On the morning of October 16, 2023 the pilot fueled up three 5-gallon fuel containers at the [privacy data omitted] (gas station) on the corner of main and… ## Docket (7 files) The files NTSB released with the investigation on October 22, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=193246. 229 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19368884&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Photo array (item 2, PDF, 2 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19410908&FileExtension=pdf&FileName=Photo%20Array-Rel.pdf - Examination summary (item 3, PDF, 4 pages, 127 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19395646&FileExtension=pdf&FileName=Examination%20Summary-Rel.pdf - Gryroplane flight manual excerpt (item 4, PDF, 1 page, 314 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19369923&FileExtension=pdf&FileName=Flight%20Manual%20Page-Rel.pdf - FAA rotorcraft flying handbook excerpt (item 5, PDF, 1 page, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19368894&FileExtension=pdf&FileName=RFH%20Page-Rel.pdf - Engine run video (item 6, MOV, 92.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19369770&FileExtension=MOV&FileName=IMG_0961-Rel.MOV - Mx record excerpt (item 7, PDF, 2 pages, 130 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19396088&FileExtension=pdf&FileName=MX%20Record%20Excerpt_Redacted-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.