# NTSB CEN11LA385: Wiley C W RV-6A, N80WW, Colgate, OK, June 13, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 13, 2011, 09:00 local (14:00 UTC) - Place: Colgate, OK - Coordinates: 34.530441, -96.210685 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.5304&lon=-96.2107&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 27, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA FSDO - NTSB case key (mKey): 80754 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11LA385 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/80754/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=80754 - Page: https://openairdocs.org/ntsb/CEN11LA385 ## Probable cause The loss of engine power for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Wiley C W RV-6A, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=05604WU), [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: Unknown or undetermined](https://openairdocs.org/ntsb-events/000); cases with it: [Wiley C W RV-6A, 1 case](https://openairdocs.org/ntsb-events/000/sequence.md?model=05604WU), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md) - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Wiley C W RV-6A, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05604WU), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Wiley C W RV-6A, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05604WU), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot stated that he was in cruise flight when the exhaust gas temperature (EGT) began to increase. He enriched the mixture slightly and the EGT returned to its previous value. Shortly thereafter, the EGT again increased and the pilot again enriched the mixture, resulting in the EGT returning to normal. This scenario repeated itself several more times before the engine lost power. Unable to restart the engine, the pilot selected a field and preformed a forced landing during which the airplane sustained substantial damage. While the airplane was operating in conditions conducive to carburetor icing at glide power at the time of the accident, the investigation was unable to determine if carburetor ice caused the power loss. Examination of the airplane and engine failed to identify a reason for the loss of engine power. ## Factual narrative On June 13, 2011 about 0900 central daylight time, a Vans RV-6A, kit-built airplane, N80WW conducted a forced landing, after experienced a loss of engine power while in cruise flight near Colgate, Oklahoma. The private pilot, sole occupant, received only minor injuries. The airplane was substantially damaged during the accident. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight originated about 0800, from the Mount Pleasant Regional Airport (OSA), Mount Pleasant, Texas, en route to Harper, Kansas. The pilot reported he departed on the cross-country flight with the airplane’s fuel tanks full; the initial departure and first part of the cruise flight was uneventful. About 40 minutes into the flight, he noticed that the engine’s exhaust gas temperature (EGT) climbed from 1380 F to 1400 F. The pilot subsequently enriched the mixture slightly and the temperature dropped back to 1380 F. The pilot then stated that everything appeared fine; however, approximately 2 minutes later, the higher EGT indication reappeared. The pilot then again enriched the mixture slightly and the EGT reading dropped back to normal. The pilot added that the same circumstances repeated itself a couple more times. Finally, after enriching the mixture all he could, the pilot stated “the engine quit as though someone closed the mixture in a routine shutdown, without any sputtering or coughing”. Unable to restart the engine, he selected a field to conduct a force landing in. During the forced landing, the airplane’s landing gear collapsed and the airplane came to rest in an upright position. The airplane was recovered to the owner’s hangar for examination. On July 28, 2011 an investigator from the NTSB and the airplane’s owner examined the airplane. The airplane’s wings and fuselage had sustained heavy damage during the forced landing; the nose landing gear had folded back into the firewall and cabin area. The engine’s carburetor located at the bottom of the engine had sustained impact damage and was broken from away from engine’s sump/intake. Additionally, the carburetor itself was broken by the impact and remained attached to the airplane by the alternate air cable. Both mixture and throttle control attachments were pulled from the carburetor. The carburetor finger and airplane’s fuel line gascolator screens were absent any contaminates or debris. Both fuel tanks were breeched during the accident; air was blown into the fuel line and through the fuel selector towards the fuel tanks. The fuel lines and fuel tank pickup points appeared clear without abnormalities. The engine driven fuel pump was partially disassembled and no abnormalities noted. A reason for the loss of power was not found. ## Aircraft - Registration: [N80WW](https://openairdocs.org/deregistered/N80WW-2011-12-08), registration cancelled 2011-12-08, S/N 22709, built 1997 (OpenAirDocs) - Reported make and model: WILEY C W RV-6A - Registry model: [Wiley C W RV-6A](https://openairdocs.org/model/wiley-c-w-rv-6a) (registry code 05604WU) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 22709 - Airframe hours: 341 - Engines: LYCOMING O-320 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, July 8, 2010 - Departed: KOSA, Mount Pleasant, TX - Destination: Harper, KS - Flight plan: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review July 16, 2009; seat: left; flight hours: 872 total, 352 in this make and model, 831 as pilot in command, 6 in the last 90 days, 4 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 68 °F - Altimeter: 29.96 inHg - Observed at: KAQR, 10 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 20110613011299A](https://openairdocs.org/incident/20110613011299A), Jun 13, 2011: Wiley C W RV-6A, Coalgate, OK, Substantial damage. Aircraft lost power, not allowing a safe landing. Aircraft crashed into field and ran into trees, substantially damaging the aircraft. Mixture was full… ## Docket (3 files) The files NTSB released with the investigation on November 18, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=80754. 2.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 620 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357630&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=40357631&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - Photo 1: Accident site with airplane (item 3, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357632&FileExtension=.PDF&FileName=Photo%201%3A%20Accident%20site%20with%20airplane-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.