# NTSB WPR21LA351: George A. Thiel Just Aircraft Highlander, N488VG, Monroe, WA, September 21, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: September 21, 2021, 14:00 local (21:00 UTC) - Place: Monroe, WA - Coordinates: 47.839997, -121.97986 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.8400&lon=-121.9799&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Western Pacific Region - Parties: FAA - NTSB case key (mKey): 103943 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA351 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103943/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103943 - Page: https://openairdocs.org/ntsb/WPR21LA351 ## Probable cause The in-flight malfunction of the throttle control pivot arm, which resulted in a total loss of engine power and the subsequent collision with terrain during the forced landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine fuel and control: fuel controlling system](https://openairdocs.org/ntsb-findings/01057320): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Thiel George A JUST AIRCRAFT (HIGHL, 1 case](https://openairdocs.org/ntsb-findings/01057320/cases.md?model=05632MA), [All aircraft, 59 cases](https://openairdocs.org/ntsb-findings/01057320/cases.md) - [Object/animal/substance](https://openairdocs.org/ntsb-findings/03022000): Environmental issues › Physical environment · Effect on operation (probable cause); cases with it: [Thiel George A JUST AIRCRAFT (HIGHL, 1 case](https://openairdocs.org/ntsb-findings/03022000/cases.md?model=05632MA), [All aircraft, 224 cases](https://openairdocs.org/ntsb-findings/03022000/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 (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Thiel George A JUST AIRCRAFT (HIGHL, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=05632MA), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) ## Analysis The pilot of the experimental amateur built airplane reported that, after descending to a local river, he increased the throttle to add power and level off, but the engine did not respond. The engine lost total power, and he attempted an in-flight engine restart to no avail. The pilot initiated a landing to a nearby island in the river, however, during the landing, the airplane’s airspeed was fast, and braking was ineffective. The pilot turned the airplane to the right toward vegetation and subsequently impacted a sandbank. The airplane sustained substantial damage to the left-wing and the empennage. A postaccident examination of the throttle control linkage revealed that the throttle control had separated at the throttle control pivot arm. The bolt, washer and nut which secured the cable to the throttle control pivot arm had backed out and were not located during the examination. Additionally, a bolt, bushing binding and nut were used to secure the throttle control pivot arm to a cross-member located between the throttle control cable and the carburetor cable binding. The return spring is designed to open the throttle to the fully open throttle position when the throttle control malfunctions. The torque on the nut that secured the pivot arm to the cross-member was excessive and consequently prevented the pivot arm from allowing the return spring to open the throttle. ## Aircraft - Registration: [N488VG](https://openairdocs.org/deregistered/N488VG-2022-06-09), registration cancelled 2022-06-09, S/N JA214-08-10, built 2013 (OpenAirDocs) - Reported make and model: George A. Thiel Just Aircraft Highlander - Registry model: [Thiel George A JUST AIRCRAFT (HIGHL](https://openairdocs.org/model/thiel-george-a-just-aircraft-highl) (registry code 05632MA) (OpenAirDocs) - Registry engine: [Jabiru 3300A](https://openairdocs.org/engine/jabiru-3300a) (registry code 34804, 4 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: JA214-08-10 - Year built: 2013 - Airframe hours: 1077.2 - Engines: Apex 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, February 5, 2021 - Departed: S50, Auburn, WA - Airport: N/A - Equipment: Electronic multifunction display, Electronic primary flight display, ADS-B, Onboard weather ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: none; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: sport pilot, with waivers/limitations; last flight review February 20, 2021; seat: left; restraint: 3-point; flight hours: 7,135 total, 1,109 in this make and model, 7,000 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 46 °F - Altimeter: 30.13 inHg - Observed at: KPAE, 13 nm away - METAR: KPAE 212053Z 01005KT 10SM CLR 20/08 A3013 RMK AO2 SLP201 T02000078 58026 ## 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 20210921016289A](https://openairdocs.org/incident/20210921016289A), Sep 21, 2021: Thiel George A JUST AIRCRAFT (HIGHL, Monre, WA, Substantial damage. PIC reduced power, desended to spot fish over the skykomish river near monroe, WA. When reapplying power, the engine did not respond. Forced landing on gravel… ## Other investigations on N488VG (1) 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. - [NTSB GAA19CA034](https://openairdocs.org/ntsb/GAA19CA034), Oct 12, 2018: Just Just Aircraft (Highl (N488VG), Monroe, WA, substantial damage. Probable cause: The pilot's improper engine modification and operation, which resulted in a total loss of engine power due to fuel starvation, and the pilot's failure to maintain an adequate approach path, which… ## Docket (4 files) The files NTSB released with the investigation on December 9, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103943. 3.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12993354&FileExtension=pdf&FileName=6120_1_Redacted-Rel%20(16)-Rel.pdf - Record of conversation - FAA inspector (item 2, PDF, 1 page, 133 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12826526&FileExtension=pdf&FileName=Record%20of%20Conversation%20-FAA%20Inspector-Rel.pdf - Photograph #1 (item 3, PDF, 1 page, 670 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12808614&FileExtension=pdf&FileName=Photograph-Rel.pdf - Examination photographs # 2 - 4 (item 4, PDF, 3 pages, 803 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12826316&FileExtension=pdf&FileName=Examination%20Photographs-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.