# NTSB CEN25LA093: Robinson Helicopter R22 Beta, N7191B, Spearman, TX, February 7, 2025 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: February 7, 2025, 16:40 local (22:40 UTC) - Place: Spearman, TX - Coordinates: 35.99768, -101.1017 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.9977&lon=-101.1017&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report January 14, 2026 - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA FSDO - NTSB case key (mKey): 199672 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN25LA093 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/199672/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=199672 - Page: https://openairdocs.org/ntsb/CEN25LA093 ## Probable cause Improperly torqued intake manifold bolts that allowed unmetered air to enter the engine, resulting in an overly lean fuel-air mixture, eventual failure of the No. 3 cylinder intake valve, and a total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Robinson Helicopter R22 BETA, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=7640110), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Robinson Helicopter R22 BETA, 7 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=7640110), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) - [Terrain: sloped/uneven terrain](https://openairdocs.org/ntsb-findings/03021017): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Robinson Helicopter R22 BETA, 4 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md?model=7640110), [All aircraft, 270 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md) - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Robinson Helicopter R22 BETA, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=7640110), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Maintenance: repair](https://openairdocs.org/ntsb-findings/02062015): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Robinson Helicopter R22 BETA, 2 cases](https://openairdocs.org/ntsb-findings/02062015/cases.md?model=7640110), [All aircraft, 99 cases](https://openairdocs.org/ntsb-findings/02062015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Robinson Helicopter R22 BETA, 5 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=7640110), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) ## Analysis The pilot reported that, while performing an aerial inspection of a fence, he heard a loud bang come from the engine and the helicopter began to shake and lose altitude. The shaking stopped momentarily but then started again and the engine lost total power. The pilot performed a forced landing, during which the helicopter impacted cedar trees and then rolled several times down a hill. The helicopter sustained substantial damage to the fuselage, tail boom, and main rotor gearbox. A postaccident inspection of the engine revealed that the No. 3 cylinder intake valve head was burned and chipped specifically on the combustion face, margin, and seat face. Additionally, the bolts that secured the intake manifold system to the engine block were loose. A review of maintenance records revealed that all four engine cylinders were removed for overhaul and reinstalled about 8 months before the accident due to low compression. According to the pilot, who was also the owner of the helicopter, about one month before the accident (about 360 hours after the cylinders were overhauled), the No. 1 cylinder was replaced due to the intake valve head being burned. According the engine manufacturer, when engine cylinders are removed and/or reinstalled, the bolts that secure the intake manifold system to the engine block need to be removed to manipulate the cylinders. It is likely that when the cylinders were removed 8 months before the accident for overhaul and reinstallation, the bolts that secured the intake manifold system to the engine block were not properly torqued when the cylinders were reinstalled. The loose intake manifold system likely allowed unmetered air into the engine, resulting in an overly lean fuel/air mixture, which resulted in damage to both the No. 1 and No. 3 cylinder intake valves. The damage to the valves would likely result in poor combustion and a decrease in engine performance. ## Factual narrative On February 7, 2025, about 1640 central standard time, a Robinson R22 helicopter, N7191B, was substantially damaged when it was involved in an accident near Spearman, Texas. The pilot was not injured, and the passenger sustained minor injuries. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that they departed near Pampa, Texas, about 1020 for an all-day wildlife management hunting expedition and to inspect fences. While inspecting a fence, the pilot heard a loud bang coming from the engine and the helicopter began to shake. The shaking stopped and then started again, and the engine lost total power. The pilot was unable to find a suitable forced landing site due to uneven terrain, and the helicopter impacted cedar trees and then rolled several times down a hill. The helicopter sustained substantial damage to the fuselage, tail boom, and main rotor gearbox. A postaccident inspection of the engine revealed that the No. 3 cylinder intake valve head was burned and chipped specifically on the combustion face, margin, and seat face. Additionally, the bolts that secured the intake manifold system to the engine block were loose. A review of maintenance records revealed that all four engine cylinders were removed for overhaul and reinstalled in June 2024 due to low compression. According to the pilot, who was the owner of the helicopter, in January 2025, about 360 hours after the engine cylinders were overhauled, the No. 1 cylinder was replaced due to the intake valve head being burned. According to the engine manufacturer, when engine cylinders are removed and/or reinstalled, the bolts that secure the intake manifold system to the engine block need to be removed to manipulate the cylinders. ## Aircraft - Registration: [N7191B](https://openairdocs.org/deregistered/N7191B-2025-04-28), registration cancelled 2025-04-28, S/N 3074, built 2000 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER R22 BETA - Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 3074 - Year built: 2000 - Airframe hours: 3900 - Engines: Lycoming O-360 124 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, January 23, 2025 - Departed: Pampa, TX - Equipment: Satellite tracking device, Handheld GPS, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 62; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review January 24, 2024; seat: right; restraint: 3-point; flight hours: 17,136 total, 15,008 in this make and model, 17,036 as pilot in command, 182 in the last 90 days, 43 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 32 °F - Altimeter: 29.79 inHg - Observed at: E42, 10 nm away - METAR: 13012KT 10SM CLR 17/01 A2979 ## 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 20250207001459A](https://openairdocs.org/incident/20250207001459A), Feb 7, 2025: Robinson Helicopter R22 BETA, Borger, TX, Substantial damage. On February 7, 2025, at approximately 1600, a Robinson R22 helicopter, hit a tree approximately four miles northwest of mesa vista ranch airport, T13. The… ## Docket (6 files) The files NTSB released with the investigation on January 14, 2026, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=199672. 6.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18909409&FileExtension=pdf&FileName=NSTB%20Form%202-8-25_Redacted-Rel.pdf - Maintenance records (item 2, PDF, 13 pages, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19522610&FileExtension=pdf&FileName=Maintenance%20Package_Redacted-Rel.pdf - Engine examination summary (item 3, PDF, 2 pages, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19583579&FileExtension=pdf&FileName=Engine%20Exam%20Notes-Rel.pdf - Photos (item 4, PDF, 4 pages, 780 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18911537&FileExtension=pdf&FileName=photos-Rel.pdf - Mor-harsanyi (item 5, PDF, 1 page, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19594249&FileExtension=pdf&FileName=MOR-Harsanyi-Rel.pdf - Party form (item 6, PDF, 1 page, 406 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19572827&FileExtension=pdf&FileName=PF-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.