# NTSB CEN21LA454: Kitfox IV, N161JB, Ozark, AR, September 24, 2021

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: September 24, 2021, 13:30 local (18:30 UTC)
- Place: Ozark, AR
- Coordinates: 35.6785, -93.7286 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.6785&lon=-93.7286&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Central Region
- Parties: Federal Aviation Administration - Little Rock FSDO
- NTSB case key (mKey): 103968
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA454
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103968/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103968
- Page: https://openairdocs.org/ntsb/CEN21LA454

## Probable cause

The pilot’s inability to maintain altitude after the airplane encountered a downdraft while he intentionally flew at a low-altitude during a practice for a short-takeoff-and-landing flight competition.

## Findings

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

- [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Bach Joseph E KITFOX IV, 1 case](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=05623AP), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md)
- [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Ability to respond/compensate (probable cause); cases with it: [Bach Joseph E KITFOX IV, 1 case](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=05623AP), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md)
- [Performance/control parameters: descent/approach/glide path](https://openairdocs.org/ntsb-findings/01062040): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Bach Joseph E KITFOX IV, 1 case](https://openairdocs.org/ntsb-findings/01062040/cases.md?model=05623AP), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md)
- [Use of equip/info](https://openairdocs.org/ntsb-findings/02063000): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bach Joseph E KITFOX IV, 1 case](https://openairdocs.org/ntsb-findings/02063000/cases.md?model=05623AP), [All aircraft, 111 cases](https://openairdocs.org/ntsb-findings/02063000/cases.md)
- [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Bach Joseph E KITFOX IV, 1 case](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=05623AP), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)

## Sequence of events

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

- [Maneuvering-low-alt flying: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Bach Joseph E KITFOX IV, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=05623AP), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md)
- [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [Bach Joseph E KITFOX IV, 1 case](https://openairdocs.org/ntsb-events/220/sequence.md?model=05623AP), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md)
- [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Bach Joseph E KITFOX IV, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05623AP), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot reported that he was conducting a practice flight for a short-takeoff-and-landings (STOL) competition. The intended flight profile was a timed course consisting of multiple takeoffs-and-landings on several turf runways to demonstrate the STOL capabilities of the airplane and the pilot flying. The pilot intentionally flew the airplane at a low altitude throughout the flight. The flight path was in a river valley with tall ridges on either side of the river and there was a known risk of encountering downdrafts while flying the course. While performing a turn toward one of the airstrips, and less than 100ft above the ground the pilot reported encountering a downdraft and descended rapidly. In response, the pilot increased the engine throttle from near idle to maximum power. The pilot reported that the engine “stumbled” briefly because of the rapidly increased throttle, so he leveled the airplane’s wings and lowered the airplane’s pitch to increase airspeed. As the airplane approached an open area for landing, the airplane’s left main landing gear struck a tree, and the airplane subsequently impacted the ground. The airplane sustained substantial damage to the fuselage and the right wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The weather conditions at the time of the accident included clear skies with light surface winds from the south.

## Aircraft

- Registration: [N161JB](https://openairdocs.org/aircraft/N161JB), registered now, S/N 1902, built 1993 (OpenAirDocs)
- Reported make and model: Kitfox IV
- Registry model: [Bach Joseph E KITFOX IV](https://openairdocs.org/model/bach-joseph-e-kitfox-iv) (registry code 05623AP) (OpenAirDocs)
- Registry engine: [Bombardier ROTAX (ALL)](https://openairdocs.org/engine/bombardier-rotax-all) (registry code 09050, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 1902
- Year built: 1993
- Airframe hours: 798.7
- Engines: Rotax UL670-BH17 93 horsepower reciprocating
- Damage: Substantial damage
- Flight: Air race/show, Part 91
- Operator: Gregory A. Jacobi
- Registered owner: Gregory A. Jacobi
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Condition, August 27, 2021, 7 hours before
- Departed: 51AR, Ozark, AR
- Airport: 51AR, Byrd's Backcountry Airstrip
- Equipment: None

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 49; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review January 30, 2020; seat: left; restraint: 4-point; flight hours: 538 total, 172 in this make and model, 511 as pilot in command, 75 in the last 90 days, 13 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 80 °F

## 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 20210924021669A](https://openairdocs.org/incident/20210924021669A), Sep 24, 2021: Bach Joseph E KITFOX IV, Ozark, AR, Substantial damage. On September 24, 2021 on or about 1345 CST, an experimental airplane, Kitfox IV, N616JB, was on a practice run for a stol competition at Byrd'S backcountry…

## Docket (4 files)

The files NTSB released with the investigation on June 10, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103968. 4.2 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13961484&FileExtension=pdf&FileName=01%20-%20Pilot%20Report_Redacted-Rel.pdf
- Memorandum of conversation (gregory a jacobi) (item 2, PDF, 2 pages, 65 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13962265&FileExtension=pdf&FileName=02%20-%20Memorandum%20of%20Conversation%20(Gregory%20A%20Jacobi)-Rel.pdf
- Arkanstol ozark backwoods challenge (textual description and course layout) (item 3, PDF, 3 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13961343&FileExtension=pdf&FileName=03%20-%20The%20Ozark%20Backwoods%20Challenge%20(Description)-Rel.pdf
- Photos (item 4, PDF, 3 pages, 3 photos, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13961673&FileExtension=pdf&FileName=04%20-%20Photos-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.