# NTSB CEN10LA241: Hager Clinton Ray Vans RV-8, N127TT, Prague, OK, May 6, 2010 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: May 6, 2010, 10:30 local (15:30 UTC) - Place: Prague, OK - Coordinates: 35.479347, -96.690887 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.4793&lon=-96.6909&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report August 11, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA FSDO - NTSB case key (mKey): 75953 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10LA241 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75953/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75953 - Page: https://openairdocs.org/ntsb/CEN10LA241 ## Probable cause The in-flight separation of a propeller blade for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Propeller system: propeller blade section](https://openairdocs.org/ntsb-findings/01046111): Aircraft › Aircraft propeller/rotor · Failure (probable cause); cases with it: [Hager Clinton Ray VANS RV-8, 1 case](https://openairdocs.org/ntsb-findings/01046111/cases.md?model=056217Y), [All aircraft, 51 cases](https://openairdocs.org/ntsb-findings/01046111/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined; cases with it: [Hager Clinton Ray VANS RV-8, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=056217Y), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) (defining event); cases with it: [Hager Clinton Ray VANS RV-8, 1 case](https://openairdocs.org/ntsb-events/338/sequence.md?model=056217Y), [All aircraft, 563 cases](https://openairdocs.org/ntsb-events/338/sequence.md) - [Emergency descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Hager Clinton Ray VANS RV-8, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=056217Y), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Hager Clinton Ray VANS RV-8, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=056217Y), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot/builder of a kit-built airplane had recently installed a three-bladed, ground adjustable propeller. He said the new propeller had about 8 flight hours and five flights on it. About 30 minutes into the flight, a single propeller blade separated. Due to the vibration, the pilot shut down the engine and performed a forced landing to a field. During the landing, the airplane bounced, nosed over and became inverted. The propeller blade lost in flight was not found, and examination of the remaining propeller hub and blades did not determine the reason for the blade separation. ## Factual narrative On May 6, 2010, about 1030 central standard time, kit built RV-8 airplane, N127TT, impacted terrain during a forced landing following a the loss of a propeller blade while in cruise flight near Prague, Oklahoma. The private pilot, sole occupant, received minor injuries. The airplane sustained substantial damage during the accident. The aircraft was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight originated from the Prague Municipal Airport (O47), Prague, Oklahoma, at about 1000. The pilot reported that he was in cruise flight for about 30 minutes when a blade from the 3-bladed propeller separated from the airplane. Due to the vibration, he shut the engine down and pulled the nose of the airplane up to stop the prop from turning. Unable to return to the airport, he elected to conduct a forced landing in a field. During the landing, the airplane missed a fence, bounced, and then flipped over, coming to rest in the inverted position. The airplane's fuselage, left wing, and vertical stabilizer were all structurally damaged in the accident. The pilot (and aircraft builder) added that he had recently installed the propeller and the accident flight was about the fifth flight, with approximately 8 flight hours on the new propeller. The propeller was identified as a ground-adjustable, 3-bladed propeller manufactured by Props, Inc. The propeller blade lost in-flight was not located; however, the remaining part of the propeller and hub was sent to the US Forest Products Laboratory, for further examination. Without the missing propeller blade, the laboratory could not determine the reason for the separation. ## Aircraft - Registration: [N127TT](https://openairdocs.org/deregistered/N127TT-2010-12-07), registration cancelled 2010-12-07, S/N 80071 (OpenAirDocs) - Reported make and model: HAGER CLINTON RAY VANS RV-8 - Registry model: [Hager Clinton Ray VANS RV-8](https://openairdocs.org/model/hager-clinton-ray-vans-rv-8) (registry code 056217Y) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 80071 - Airframe hours: 175 - Engines: Lycoming IO-320 reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, September 14, 2009 - Departed: Prague, OK - Destination: Prague, OK - Flight plan: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 67; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; seat: front; flight hours: 4,600 total, 175 in this make and model, 4,600 as pilot in command, 15 in the last 90 days, 6 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 73 °F, dew point 61 °F - Altimeter: 29.82 inHg - Observed at: KSRE, 13 nm away ## 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 20100506033099A](https://openairdocs.org/incident/20100506033099A), May 6, 2010: Hager Clint VANS RV-8, Prague, OK, Substantial damage. Pilot states acft at approx 3000FT when prop blade seperated from acft. Pilot shut down engine attempted to land at Prague arpt. At 800 ft realized would not… ## Docket (7 files) The files NTSB released with the investigation on June 15, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75953. 2.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 540 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40346158&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Reports and Records (item 2, .PDF, 30 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40346159&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - USDA Laboratory Report (item 3, .PDF, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348015&FileExtension=.PDF&FileName=USDA%20Laboratory%20Report-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 4, .PDF, 29 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348017&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Redacted.PDF - Photo: Accident aircraft (owner photo) (item 5, .PDF, 288 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348019&FileExtension=.PDF&FileName=Photo%3A%20Accident%20aircraft%20%20(owner%20photo)-Master.PDF - Photo: Propeller hub (owner photo) (item 6, .PDF, 259 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348021&FileExtension=.PDF&FileName=Photo%3A%20Propeller%20hub%20%20(owner%20photo)-Master.PDF - Photo: Missing propeller blade attachment point (owner photo) (item 7, .PDF, 188 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348022&FileExtension=.PDF&FileName=Photo%3A%20Missing%20propeller%20blade%20attachment%20point%20(owner%20photo)-Master.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.