# NTSB CEN19LA313: Jackson Velocity, N2XF, Mack, CO, September 3, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: September 3, 2019, 10:00 local (16:00 UTC) - Place: Mack, CO - Coordinates: 39.268054, -108.864166 - Nearby events: https://openairdocs.org/map.md?lat=39.2681&lon=-108.8642&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-climb to cruise: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - NTSB case key (mKey): 100232 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19LA313 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100232/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100232 - Page: https://openairdocs.org/ntsb/CEN19LA313 ## Probable cause A propeller overspeed due to failure of the electronic ignition timing ring attachment screws, and a runway overrun during the subsequent forced landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Propeller system: propeller controlling system](https://openairdocs.org/ntsb-findings/01046120): Aircraft › Aircraft propeller/rotor · Failure (probable cause); cases with it: [Jackson R D/Marini R J VELOCITY XL-RG, 1 case](https://openairdocs.org/ntsb-findings/01046120/cases.md?model=05616PO), [All aircraft, 25 cases](https://openairdocs.org/ntsb-findings/01046120/cases.md) - [Performance/control parameters: surface speed/braking](https://openairdocs.org/ntsb-findings/01062045): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Jackson R D/Marini R J VELOCITY XL-RG, 1 case](https://openairdocs.org/ntsb-findings/01062045/cases.md?model=05616PO), [All aircraft, 238 cases](https://openairdocs.org/ntsb-findings/01062045/cases.md) - [Ignition system](https://openairdocs.org/ntsb-findings/01057400): Aircraft › Aircraft power plant · Damaged/degraded (probable cause); cases with it: [Jackson R D/Marini R J VELOCITY XL-RG, 1 case](https://openairdocs.org/ntsb-findings/01057400/cases.md?model=05616PO), [All aircraft, 18 cases](https://openairdocs.org/ntsb-findings/01057400/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Jackson R D/Marini R J VELOCITY XL-RG, 1 case](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=05616PO), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/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: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Jackson R D/Marini R J VELOCITY XL-RG, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=05616PO), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Jackson R D/Marini R J VELOCITY XL-RG, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05616PO), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Landing gear not configured](https://openairdocs.org/ntsb-events/095); cases with it: [Jackson R D/Marini R J VELOCITY XL-RG, 1 case](https://openairdocs.org/ntsb-events/095/sequence.md?model=05616PO), [All aircraft, 584 cases](https://openairdocs.org/ntsb-events/095/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Jackson R D/Marini R J VELOCITY XL-RG, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=05616PO), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Jackson R D/Marini R J VELOCITY XL-RG, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05616PO), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The commercial pilot departed on a business flight in the experimental airplane in visual meteorological conditions. As the airplane was passing 15,000 ft en route to its assigned cruising altitude of 18,000 ft, the propeller started to overspeed. The pilot reduced the propeller rpm and manifold pressure but reported that he was unable to find a power setting that would allow the airplane to maintain level flight. Air traffic control provided the pilot with vectors to a nearby airport, where the pilot performed a power-off approach and waited until the landing was assured before lowering the landing gear. The airplane touched down halfway down the runway. The main landing gear was not completely extended, rendering the brakes inoperable, and during the landing roll, the airplane impacted an irrigation pipe, slid off the departure end of the runway, and came rest in a field. Postaccident examination revealed no discrepancies with the propeller or governor. The screws securing the electronic ignition timing ring to the three brackets bolted to the crankshaft at the propeller stud flange had failed, damaging the timing disk and sensors. The damage caused by the loose screws caused the engine to slow from about 2,700 rpm to about 2,550 rpm. The propeller governor then decreased the propeller pitch to bring the propeller rotation back up to speed, but once the obstruction of the ingested screws cleared and the friction was released, the low-pitch blades allowed the propeller to overspeed. Thus, the overspeed was likely caused by the propeller governor's reaction to a slight slow down of engine speed when the timing ring attachment screws backed out and damaged the electronic ignition timing sensors. ## Factual narrative On September 3, 2019, about 1000 mountain daylight time, a Jackson/Marini Velocity XL-RG, N2XF, was substantially damaged when it was involved in an accident at Mack Mesa Airport (10CO), Mack, Colorado. The commercial pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 business flight. The airplane departed Grand Junction Regional Airport (GJT), Grand Junction, Colorado, at 0925, and was en route to Ravalli County Airport (6S5), Hamilton, Montana. According to the pilot's written statement, the airplane was climbing to its assigned cruising altitude of flight level (FL) 180 (18,000 ft). Climb power was set at 2,700 revolutions per minute (RPM) and 30 inches of manifold pressure (MAP) that resulted in a fuel flow of 34 gallons per hour (GPH). As the airplane passed 15,000 ft, the propeller started to overspeed to about 3,450 RPM. The pilot reduced engine RPM and MAP and advised Denver air route traffic control center (ARTCC). He was given vectors to 10CO. The pilot made a power-off approach to runway 07 and waited until the landing was assured before lowering the landing gear. Because of excessive speed, the airplane touched down halfway down the runway. The nose gear was down but the main landing gear was not completely extended, negating the pilot's application of brakes. During the landing roll, the airplane slid off the departure end of the runway, struck an irrigation pipe that knocked off the left rudder, and came rest in a clover field. The airplane was trucked back to the pilot's hangar at Orlando Apopka Airport (X04), Apopka, Florida, for repairs. Bench testing and disassembly of the MT propeller and governor by Air Prop Specialists, Inc., in Mariana, Florida, revealed no discrepancies. The screws that secured the timing ring to the three brackets that were bolted to the crankshaft at the propeller stud flange had failed, damaging the timing disk and sensors. The pilot said that the damage occurred just prior to the overspeed and was not the result of the overspeed or landing rollout. He said the overspeed was caused by the propeller governor's reaction to the slight slow down of engine speed that occurred ten seconds prior to the overspeed when the timing ring attachment screws backed out, damaging the electronic ignition timing sensors. The interference to rotation and damage caused by the loose screws caused the slowdown from about 2,700 rpm to about 2,550 rpm. The propeller governor decreased propeller pitch to bring the propeller rotation back up to speed but once the obstruction of the ingested screws cleared and the friction was released, the low pitch blades allowed the propeller to overspeed. ## Aircraft - Registration: [N2XF](https://openairdocs.org/aircraft/N2XF), registered now, S/N 3RX029, built 2008 (OpenAirDocs) - Reported make and model: Jackson Velocity (XL-RG) - Registry model: [Jackson R D/Marini R J VELOCITY XL-RG](https://openairdocs.org/model/jackson-r-d-marini-r-j-velocity-xl-rg) (registry code 05616PO) (OpenAirDocs) - Registry engine: [Continental TSIO-520-N](https://openairdocs.org/engine/continental-tsio-520-n) (registry code 17264, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 3RX029 - Year built: 2008 - Airframe hours: 1420 - Engines: Continental TSIO-550-C 300 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Departed: GJT, Grand Junction, CO - Destination: 10CO, Mack, CO - Flight plan: IFR - Airport: 10CO, Mack Mesa, runway 07, 2,600 × 60 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3; last flight review December 1, 2017; seat: left; flight hours: 3,000 total, 1,410 in this make and model, 30 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 46 °F - Altimeter: 30.26 inHg - Observed at: GJT, 19 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 20190903014649A](https://openairdocs.org/incident/20190903014649A), Sep 3, 2019: Jackson R D/Marini R J VELOCITY XL-RG, Mack, CO, Substantial damage. PIC stated approx. 10 minutes into climb from gjt, passing approx. 15,000 MSL, the engine without provocation suddenly over sped to approx. 3450 RPM. PIC… ## Docket (3 files) The files NTSB released with the investigation on April 15, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100232. 3.8 MB in all. - Pilot's Statement with Photos (item 1, .PDF, 730 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482485&FileExtension=.PDF&FileName=Pilot%27s%20Statement%20with%20Photos-Master.PDF - Report from Air Prop Specialists, Inc. (item 2, .PDF, 379 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482486&FileExtension=.PDF&FileName=Report%20from%20Air%20Prop%20Specialists,%20Inc.-Master.PDF - Report Photographs (item 3, .PDF, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482487&FileExtension=.PDF&FileName=Report%20Photographs-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.