# NTSB WPR23LA269: CSP Leasing MTO Sport, N207AG, Gardiner, MT, June 1, 2023 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: June 1, 2023, 10:21 local (16:21 UTC) - Place: Gardiner, MT - Coordinates: 45.048254, -110.74503 - Nearby events: https://openairdocs.org/map.md?lat=45.0483&lon=-110.7450&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 192600 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR23LA269 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192600/pdf - Page: https://openairdocs.org/ntsb/WPR23LA269 ## Probable cause Failure of the rudder/nosewheel steering system for reasons that could not be determined, which resulted in loss of yaw control and a subsequent rollover. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [CSP Leasing MTO SPORT, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=05634OH), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Flight control system: rudder control system](https://openairdocs.org/ntsb-findings/01022720): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [CSP Leasing MTO SPORT, 1 case](https://openairdocs.org/ntsb-findings/01022720/cases.md?model=05634OH), [All aircraft, 93 cases](https://openairdocs.org/ntsb-findings/01022720/cases.md) - [Landing gear system: landing gear steering system](https://openairdocs.org/ntsb-findings/01023250): Aircraft › Aircraft systems · Failure; cases with it: [CSP Leasing MTO SPORT, 1 case](https://openairdocs.org/ntsb-findings/01023250/cases.md?model=05634OH), [All aircraft, 32 cases](https://openairdocs.org/ntsb-findings/01023250/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Unknown or undetermined](https://openairdocs.org/ntsb-events/000); cases with it: [CSP Leasing MTO SPORT, 1 case](https://openairdocs.org/ntsb-events/000/sequence.md?model=05634OH), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md) - [Landing-landing roll: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [CSP Leasing MTO SPORT, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=05634OH), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [CSP Leasing MTO SPORT, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=05634OH), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [CSP Leasing MTO SPORT, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=05634OH), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Landing-landing roll: Roll over](https://openairdocs.org/ntsb-events/097); cases with it: [CSP Leasing MTO SPORT, 1 case](https://openairdocs.org/ntsb-events/097/sequence.md?model=05634OH), [All aircraft, 261 cases](https://openairdocs.org/ntsb-events/097/sequence.md) ## Analysis The pilot landed on the runway with about 10 mph forward speed. After touchdown, the gyroplane veered to the right despite the pilot’s full use of opposite rudder and nosewheel steering. The gyroplane rolled onto its right side and off the runway, which substantially damaged the rotor mast. Postaccident examination of the rudder/nosewheel steering system revealed that the mechanical stop was bent. There was overstress damage to three of the four control rods which likely occurred when the nosewheel turned beyond its limit during the accident landing. The manufacturer’s construction of the rudder/nosewheel steering assembly met British Civil Airworthiness Requirements (BCAR) Section T, “Light Gyroplanes” standards. No preimpact mechanical malfunctions or anomalies were observed that would have precluded normal operation. The airport’s website described the runway as being in poor condition, with cracks and vegetation growth throughout. However, the pilot was aware of the conditions and had made two successful landings before the accident landing. Wind conditions were reported as variable at 5 knots and likely did not influence the landing. Although the steering system’s mechanical stop may have become bent during either the accident landing or a previous landing, the investigation was not able to determine the source of the bent stop. ## Factual narrative On June 1, 2023, about 1000 mountain daylight time, an experimental, amateur-built MTO Sport gyroplane, N207AG, was substantially damaged when it was involved in an accident near Gardiner, Montana. The pilot received minor injuries. The gyroplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, before the accident, he performed two takeoffs and two landings, then departed for a short local flight. When he returned, he performed an approach to land on runway 10. After the touchdown on the runway, while at a forward speed of about 10 mph, the gyroplane suddenly yawed to the right, despite the pilot’s application of full left rudder and nosewheel steering. The gyroplane then rolled to the left and the rotors contacted the runway, which substantially damaged the rotor mast. The pilot, who was seated in the front seat, received minor injuries. The gyroplane came to rest on its right side, off the left side of the runway. All major components remained attached to the airframe, except for a segment of one rotor blade. Postaccident examination revealed the left side of the metal mechanical stop for the nosewheel was bent downward, and the nosewheel was turned right, beyond the mechanical stop limit. Three of the four control rods that provide rudder movement and nosewheel steering had fractured and separated from their respective rod end bearings, as shown in figure 1. No preimpact mechanical malfunctions or anomalies were observed that would have precluded normal operation. Figure 1. Image showing the nosewheel displaced to the right beyond the mechanical stop limit, the two partially separated front seat rudder/nosewheel control rods, and the back seat, left-side control rod. (Source: FAA) Further examination of the control rods revealed that each control rod separated through the threaded end of one of the rod end bearings. The separations occurred through one of the top threads whose thread root was inline with the top of the mating nut. The macro shapes of the separations were cup-and-cone, which is consistent with overstress. The fracture surface for the longest control rod had intergranular features consistent with tensile overstress, possibly due to low toughness. The fracture surfaces on the other two control rods had features consistent with ductile tensile overstress. The gyroplane was a two-seat model with flight controls installed for both seats. According to the manufacturer, “The rear rudder pedals are connected to the rudder via steel cables, and to the front pedals by linkages [control rods] via the nosewheel for steering. Pushing the right pedal will turn the aircraft right in the air and right when on the ground.” Figure 2 is an excerpt from the manufacturer’s maintenance manual and details how the design controlled both the rudder and the nosewheel steering. Figure 2. Excerpt from the manufacturer’s maintenance manual, showing pedals, control rods, and cables that control therudder and nosewheel steering. (Source: Manufacturer) According to the manufacturer, the nosewheel limit stop withstands the pedal forces and butts up against the center keel tube of the gyroplane. The design was built to BCAR Section T, “Light Gyroplanes” standards. According to the manufacturer, normal pilot inputs will not bend the stop. A visual examination of the mechanical stop revealed the left-side stop was bent downward, which allowed the nosewheel to travel beyond its mechanical limit. The closest weather reporting facility was Billings Logan International Airport (BIL), Billings, Montana. An automated weather report around the time of the accident recorded wind variable at 5 knots, 10 statute miles visibility, few clouds at 6,500 ft, few clouds at 10,000 ft, scattered clouds at 24,000 ft, temperature 24°C, dew point 11°C. The pilot reported the weather as fair and calm. According to a Gardiner Airport website, the runway conditions were described as “asphalt/aggregate friction seal coat, in poor condition. LARGE CRACKS AND VEGETATION GROWTH THROUGHOUT RUNWAY SURFACE.” ## Aircraft - Registration: [N207AG](https://openairdocs.org/aircraft/N207AG), registered now, S/N M01311, built 2015 (OpenAirDocs) - Reported make and model: CSP LEASING LLC MTO SPORT - Registry model: [CSP Leasing MTO SPORT](https://openairdocs.org/model/csp-leasing-mto-sport) (registry code 05634OH) (OpenAirDocs) - Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs) - Category: Gyroplane, amateur-built - Serial number: M01311 - Year built: 2015 - Airframe hours: 772 - Engines: Rotax 912ULS 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, April 28, 2023 - Destination: Same as departure - Airport: 29S, Gardiner Airport, runway 10, 3,200 × 55 ft, asphalt - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; injuries: none; sport pilot; seat: front; restraint: 4-point; flight hours: 1,500 total, 100 in this make and model, 1,500 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Temperature: 75 °F, dew point 52 °F - Altimeter: 29.87 inHg - Observed at: KBIL, 103 nm away - METAR: METAR KBIL 011753Z VRB05KT 10SM FEW065 FEW100 SCT240 24/11 A2987 RMK AO2 SLP088 CB TCU DSNT SE-S SW-NW SHRA DSNT SE-S T02440106 10244 20117 51002= ## 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 20230601013549A](https://openairdocs.org/incident/20230601013549A), Jun 1, 2023: Csp Leasing LLC MTO SPORT, Gardiner, MT, Substantial damage. Before departing the airport (29S) the pilot completed a "touch and go landing" then proceeded on an approximately 2 hour flight. Upon return to the airport… 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.