# NTSB WPR18LA030: Vanderark RV-10, N917VA, Sun Lakes, AZ, November 12, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: November 12, 2017, 10:25 local (17:25 UTC) - Place: Sun Lakes, AZ - Coordinates: 33.242778, -111.926391 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.2428&lon=-111.9264&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Emergency descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report July 23, 2019 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 96316 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR18LA030 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96316/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96316 - Page: https://openairdocs.org/ntsb/WPR18LA030 ## Probable cause The fatigue fractures of the upper and lower alternator attachment bolts, which decreased the common drive belt tension and resulted in the subsequent in-flight separation of an alternator drive belt, the overheating of the engine, and the subsequent total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng liquid cooling](https://openairdocs.org/ntsb-findings/01058570): Aircraft › Aircraft power plant · Inoperative (probable cause); cases with it: [Vanderark Jan R RV-10, 1 case](https://openairdocs.org/ntsb-findings/01058570/cases.md?model=0563237), [All aircraft, 17 cases](https://openairdocs.org/ntsb-findings/01058570/cases.md) - [Electrical power system: alternator-generator drive sys](https://openairdocs.org/ntsb-findings/01022410): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Vanderark Jan R RV-10, 1 case](https://openairdocs.org/ntsb-findings/01022410/cases.md?model=0563237), [All aircraft, 25 cases](https://openairdocs.org/ntsb-findings/01022410/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-climb to cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340); cases with it: [Vanderark Jan R RV-10, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=0563237), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Emergency descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Vanderark Jan R RV-10, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=0563237), [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: [Vanderark Jan R RV-10, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=0563237), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Vanderark Jan R RV-10, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=0563237), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The private pilot reported that, during the en route climb, he smelled antifreeze and realized that the engine was overheating. He then reduced power to idle and turned the airplane back toward the departure airport. As the airplane descended, the pilot added power, but the engine did not respond. He decided to land at a nearby closed airport; however, when he realized that the airplane would be unable to reach it, he performed a forced landing to a desert. During the landing roll, the airplane struck several bushes, which resulted in the nosewheel and left main landing gear collapsing and the left wing and fuselage sustaining substantial damage. The airplane was powered by a modified automobile engine, which was equipped with two alternators and a water pump to circulate the engine coolant. The common drive belt that connected the two alternators and water pump was found detached. In addition, the upper and lower attachment bolts that secured one of the alternators were fractured, and the alternator was partially displaced. Examination of the fracture surfaces of both bolts revealed that they exhibited rachet marks, consistent with fatigue fractures. It is likely that, once the alternator attachment bolts fractured, the common drive belt tension decreased, which resulted in the separation of the belt. The belt separation would have precluded the water pump from operating and led to the engine overheating and eventually losing total power. ## Factual narrative On November 12, 2017, about 1025 mountain standard time, an experimental amateur built Vanderark RV-10 airplane, N917VA, impacted terrain and vegetation during a forced landing following a loss of engine power near Sun Lakes, Arizona. The private pilot was not injured; the airplane was substantially damaged. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight which originated from the Chandler Municipal Airport (CHD), Chandler, Arizona, about 1015.The pilot reported that while about 15 miles south of CHD and climbing through 4,000 ft mean sea level (msl), he noticed the smell of antifreeze and realized the engine was overheating. He reduced power to idle and executed a 180° turn toward CHD. As the airplane descended through about 1,500 ft, he added power but the engine did not respond. He attempted to land at a nearby closed airport, however, realized he was unable to reach it, and subsequently initiated a forced landing to an area of open desert. During the landing roll, the airplane struck several scrub bushes and the nose wheel and left main landing gear collapsed. Examination of the airplane by the pilot revealed that the left wing and fuselage were structurally damaged. The airplane was powered by an LS1 series, eight-cylinder, liquid cooled automobile engine, manufactured by General Motors. It was equipped with two alternators and a water pump to circulate engine coolant. The alternators and water pump were connected by a common "serpentine" drive belt and driven by a pulley on the crankshaft. The pilot reported that at the time of the accident, the airframe and engine had accumulated 51 hours total operational time. Postaccident examination revealed that one of the two alternators was partially displaced, and that its upper and lower attach bolts were fractured. Examination further revealed that the alternator belt had detached. Examination of the fractured bolts was conducted by a specialist from the NTSB Materials Laboratory. The lower attach bolt exhibited a fracture in the threaded portion of the bolt shank. The fracture surface of the lower attach bolt was smeared and damaged by apparent re-contact. The fracture surface was flat and perpendicular to the axis of the bolt shank with an area exhibiting a shear lip on one side. Ratchet marks were observed on the side opposing the shear lip, consistent with a fatigue fracture. The upper attach bolt also exhibited a fracture in the threaded portion of the bolt shank. The fracture surface exhibited ratchet marks on the periphery and crack arrest fronts extending towards the opposing side consistent with a fatigue fracture. ## Aircraft - Registration: [N917VA](https://openairdocs.org/aircraft/N917VA), registered now, S/N 40076, built 2014 (OpenAirDocs) - Reported make and model: VANDERARK RV-10 - Registry model: [Vanderark Jan R RV-10](https://openairdocs.org/model/vanderark-jan-r-rv-10) (registry code 0563237) (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: 40076 - Year built: 2014 - Airframe hours: 51 - Engines: Chevrolet LS1 290 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Departed: CHD, Chandler, AZ - Destination: CHD, Chandler, AZ - Equipment: Electronic primary flight display, Electronic multifunction display, ADS-B, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review November 28, 2015; seat: left; restraint: 3-point; flight hours: 840 total, 54 in this make and model, 815 as pilot in command, 22 in the last 90 days, 9 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 20,000 ft broken - Temperature: 70 °F, dew point 36 °F - Altimeter: 30.06 inHg - Observed at: KCHD, 6 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 20171112019129A](https://openairdocs.org/incident/20171112019129A), Nov 12, 2017: Vanderark Jan R RV-10, Sun Lakes, AZ, Substantial damage. The pilot experienced a smell of anti freeze as he flew thru 4000' and noticed his temp gage in the red. He initiated a turn back to chandler airport and… ## Docket (3 files) The files NTSB released with the investigation on December 6, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96316. 6.2 MB in all. - NTSB Materials Laboratory Report (item 1, .PDF, 7 photos, 502 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468986&FileExtension=.PDF&FileName=NTSB%20Materials%20Laboratory%20Report-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 5.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468987&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 3, .PDF, 121 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40468988&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-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.