# NTSB CEN21LA100: Walton Daniel J Sonex, N610DJ, Pecatonica, IL, December 24, 2020

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Class 3 · Limited · Final report
- Date: December 24, 2020, 14:40 local (20:40 UTC)
- Place: Pecatonica, IL
- Coordinates: 42.303868, -89.344838 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.3039&lon=-89.3448&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach-VFR pattern base: Unknown or undetermined](https://openairdocs.org/ntsb-events/000)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report December 24, 2020
- Report: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Central Region
- Parties: FAA Flight Standards District Office
- NTSB case key (mKey): 102461
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA100
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102461/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102461
- Page: https://openairdocs.org/ntsb/CEN21LA100

## Probable cause

A total loss of engine power for reasons that could not be determined based on the available information, and the pilot’s exceedance of the airplane’s critical angle of attack following the loss of engine power, which resulted in an aerodynamic stall/spin and impact with terrain.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Unknown/Not determined (probable cause); cases with it: [Walton Daniel J SONEX, 1 case](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=05629US), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Walton Daniel J SONEX, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=05629US), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Walton Daniel J SONEX, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=05629US), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Approach-VFR pattern base: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Walton Daniel J SONEX, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05629US), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Approach-VFR pattern base: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) (defining event); cases with it: [Walton Daniel J SONEX, 1 case](https://openairdocs.org/ntsb-events/000/sequence.md?model=05629US), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md)
- [Approach-VFR pattern base: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Walton Daniel J SONEX, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=05629US), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md)
- [Approach-VFR pattern base: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Walton Daniel J SONEX, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=05629US), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Approach-VFR pattern base: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Walton Daniel J SONEX, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=05629US), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md)
- [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Walton Daniel J SONEX, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05629US), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot did not provide a statement regarding the accident. Information from the Federal Aviation Administration indicated that, while on the downwind leg of the airport traffic pattern for landing, the pilot reduced engine power and the engine lost total power. The airplane continued in a left turn toward the runway while the pilot attempted to restart the engine. The airplane entered a stall/spin and impacted terrain, resulting in substantial damage. Postaccident examination of the airplane and engine did not reveal any anomalies that would have precluded normal operation, and the reason for the loss of engine power could not be determined. Based on the available information, the circumstances of the accident are consistent with the pilot’s exceedance of the airplane’s critical angle of attack following a loss of engine power, which resulted in an aerodynamic stall/spin and impact with terrain.

## Factual narrative

On December 24, 2020, about 1440 central standard time, an experimental, amateur-built Sonex, N610DJ, was involved in an accident near Pecatonica, Illinois. The pilot sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The pilot did not provide a statement regarding the accident. Information from the Federal Aviation Administration indicated that, when the pilot reduced engine power to 2,000 rpm while on the downwind leg of the traffic pattern for landing, the engine lost total power. The airplane remained in a left turn while the pilot attempted to restart the engine, and the pilot stated that he lost control effectiveness during the turn. The airplane entered a stall/spin, then impacted terrain. The airplane sustained substantial damage to the fuselage and wings. Postaccident examination of the airplane revealed that the fuel tank was at least 1/3 full of fuel and was leaking from impact damage. The fuel lines to the engine were attached and secure. The engine could be rotated, and engine drive train and valve train continuity were confirmed. The carburetor bowl contained 100 low lead aviation fuel, and the carburetor float moved freely. The spark plugs electrodes exhibited normal coloration/features.

## Aircraft

- Registration: [N610DJ](https://openairdocs.org/aircraft/N610DJ), registered now, S/N 0959, built 2010 (OpenAirDocs)
- Reported make and model: WALTON DANIEL J SONEX
- Registry model: [Walton Daniel J SONEX](https://openairdocs.org/model/walton-daniel-j-sonex) (registry code 05629US) (OpenAirDocs)
- Registry engine: [Aerovee 2180](https://openairdocs.org/engine/aerovee-2180) (registry code 01400, 4 cycle) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 0959
- Year built: 2010
- Engines: AEROVEE 2180 80 horsepower
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Pilot
- Registered owner: Schroepfer Andrew M
- Airworthiness certificate: Special, Experimental (Special)
- Departed: DNV, Danville, IL
- Destination: Same as departure
- Airport: 8IL5, Pecatonica, runway 9, 1,800 × 70 ft, grass/turf
- Equipment: Unknown

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; injuries: serious; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; flight hours: 120 total, 70 in this make and model, 40 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 290° at 14 knots, gusting 21
- Visibility: 8 statute miles
- Lowest ceiling: 3,600 ft broken
- Temperature: 16 °F, dew point 1 °F
- Altimeter: 29.84 inHg
- Observed at: KRFD, 13 nm away
- METAR: KRFD 241754Z 29014G21KT 8SM -SN SCT025 BKN036 OVC042 M09/M17 A2984 RMK AO2 SLP117 P0000 60000 T10891172 11078 21111 51007

## 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 20201224020249A](https://openairdocs.org/incident/20201224020249A), Dec 24, 2020: Walton Daniel J SONEX, Pecatonica, IL, Substantial damage. On December 24, 2020, N610DJ, a Walton Daniel J Sonex aircraft, was preparing to land at o?c?onnor field (8IL5) after a VFR flight that originated at vermilion…

## Docket (5 files)

The files NTSB released with the investigation on June 21, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102461. 578 KB in all.

- Request for pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 1 page, 79 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13210831&FileExtension=pdf&FileName=NTSB%20Form%206120%20N610DJ%20to%20Pilot_Redacted-Rel.pdf
- Memorandum for record - 6120 form request (item 2, PDF, 1 page, 108 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13212253&FileExtension=pdf&FileName=Memoranum%20for%20Record%20-%20Request%20for%206120_Redacted-Rel.pdf
- Memorandum - history of flight (item 3, PDF, 1 page, 109 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13212301&FileExtension=pdf&FileName=Memoranum%20-%20History%20of%20Flight-Rel.pdf
- Record of conversation - FAA (item 4, PDF, 1 page, 107 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13211423&FileExtension=pdf&FileName=RECORD%20OF%20CONVERSATION%20FAA-Rel.pdf
- Photo log (item 5, PDF, 1 page, 175 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13210491&FileExtension=pdf&FileName=Photo%20Log-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.

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