# NTSB WPR20LA040: Vans RV 6, N616RV, Pima, AZ, December 5, 2019 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: December 5, 2019, 15:20 local (22:20 UTC) - Place: Pima, AZ - Coordinates: 32.901943, -109.786666 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.9019&lon=-109.7867&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Minor injuries - Injuries: 2 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): 100685 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20LA040 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100685/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100685 - Page: https://openairdocs.org/ntsb/WPR20LA040 ## Probable cause A total loss of engine power for reasons that could not be determined based on the available evidence. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Power plant](https://openairdocs.org/ntsb-findings/01057100): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Dunlap Charles RV-6, 1 case](https://openairdocs.org/ntsb-findings/01057100/cases.md?model=05610FV), [All aircraft, 198 cases](https://openairdocs.org/ntsb-findings/01057100/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Dunlap Charles RV-6, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=05610FV), [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: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Dunlap Charles RV-6, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05610FV), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Enroute: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Dunlap Charles RV-6, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05610FV), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-flare/touchdown: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Dunlap Charles RV-6, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=05610FV), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that, while the airplane was traveling westbound at 1,100 ft above the ground, the engine stopped producing power without warning. The propeller continued to windmill. The pilot initiated a 180° turn back toward the airport and attempted to restart the engine but was unable to do so. The pilot decided to land the airplane onto a nearby cotton field. When the airplane touched down, the landing gear sunk into the soft dirt, and nosed over. During a postaccident examination, the engine was able to be started, but it operated poorly and was smoking before it stopped producing power. Disassembly of the engine revealed that the two rotors and five of the six apex seals remained intact. The remaining apex seal was fractured in half. It was not possible to determine whether the apex seal fractured before or during the accident sequence. No other anomalies were revealed. The available evidence for this accident precluded a determination of whether the fractured apex seal caused the total loss of engine power. ## Factual narrative On December 5, 2019, about 1520 mountain standard time, a Vans RV-6 airplane, N616RV, sustained substantial damage when it was involved in an accident near Pima, Arizona. The pilot and passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, while the airplane was traveling westbound at 1,100 ft above the ground, the engine stopped producing power without warning. The propeller continued to windmill. The pilot initiated a 180° turn back toward the airport and attempted to restart the engine but was unable to do so. He decided to land the airplane onto a nearby cotton field. When the airplane touched down, the landing gear sunk into the soft dirt, and the airplane flipped onto its back. The vertical stabilizer and rudder sustained substantial damage. The airplane was equipped with a 150 hp Mazda 13B engine. A postaccident examination found that ignition and fuel were still available to the engine. The engine started normally but operated poorly, and smoke was emanating from it. Shortly afterward, the engine stopped producing power. Disassembly of the engine revealed that the two rotors and five of the six apex seals remained intact. The remaining apex seal was fractured in half; no other anomalies were noted. ## Aircraft - Registration: [N616RV](https://openairdocs.org/aircraft/N616RV), registered now, S/N 24491, built 2000 (OpenAirDocs) - Reported make and model: Vans RV 6 - Registry model: [Dunlap Charles RV-6](https://openairdocs.org/model/dunlap-charles-rv-6) (registry code 05610FV) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 24491 - Year built: 2000 - Airframe hours: 853 - Engines: Mazda 13B 150 horsepower unknown - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, November 1, 2019 - Departed: SAD, Safford, AZ - Destination: SAD, Safford, AZ - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review November 1, 2019; seat: left; restraint: 3-point; flight hours: 1,500 total, 830 in this make and model, 1,500 as pilot in command, 6 in the last 90 days, 0 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 43 °F - Altimeter: 30.09 inHg - Observed at: SAD, 8 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). - [Incident 20191205021189I](https://openairdocs.org/incident/20191205021189I), Dec 5, 2019: Dunlap Charles RV-6, Pima, AZ, Substantial damage. During cruise at 1100' AGL, the aircraft experienced a sudden loss of power/engine failure. The experimental, amateur built aircraft is equipped with a mazda… ## Docket (3 files) The files NTSB released with the investigation on June 8, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100685. 7.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 7.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13758388&FileExtension=pdf&FileName=6120%20final%20PRINTED_Redacted-Rel.pdf - Record of conversation - regarding postaccident examination (item 2, PDF, 1 page, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13768205&FileExtension=pdf&FileName=pilot%20ROC-Rel.pdf - On scene photo and map of flight path - courtesy of the pilot/owner (item 3, PDF, 2 pages, 321 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13760045&FileExtension=pdf&FileName=on%20scene%20photo%20and%20flight%20map-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.