CEN21LA288

NTSB accident investigation · Vining SD1 Minisport · Butler, OH · June 23, 2021

Accident · No injuriesClass 3 · LimitedFinal report
Date
June 23, 2021, 10:15 local (14:15 UTC)
Place
Butler, OH · cornfield adjacent to grass runway
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Takeoff
Aircraft
N72DXVining SD1 Minisport
Defining event
Takeoff: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
Federal Aviation Administration
FAA report
20210623011889A
Case key
103321

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot’s failure to maintain adequate airspeed following a partial loss of engine power, which resulted in an aerodynamic stall and impact with terrain. The reason for the partial loss of engine power could not be determined based on available information.

Findings · 4

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Engine (reciprocating)Aircraft › Aircraft power plant · Unknown/Not determinedVining John K SD-1 MINISPORT: 1 caseAll aircraft: 497 casesProbable cause
Wind: crosswindEnvironmental issues › Conditions/weather/phenomena · Effect on operationVining John K SD-1 MINISPORT: 1 caseAll aircraft: 1,008 cases
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedVining John K SD-1 MINISPORT: 1 caseAll aircraft: 1,681 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

A line of trees paralleled the runway on the southwest side, and a cornfield was on the northeast side. As the pilot taxied to the end of runway 13, he noted a significant crosswind from over the tree line. After a normal runup, he increased to full power. Immediately after the airplane lifted off the ground, it drifted to the right over the cornfield. The airplane “seemed to have too little power to climb” and the airplane stalled, touching down in the field. The left main landing gear separated, and the airplane spun to a stop. A postaccident examination of the engine revealed a crack in the pressure vacuum line; however, it could not be determined whether the crack could have caused a reduction in engine power. The circumstances of the accident are consistent with the pilot’s failure to maintain adequate airspeed following a partial loss of engine power during takeoff, which resulted in an aerodynamic stall.

Factual narrative

On June 23, 2021, at 1015 eastern daylight time, an experimental amateur-built SD-1 Minisport airplane, N72DX, was substantially damaged when it was involved in an accident at Freeman Swank Farms Airport (0OH5), Butler, Ohio. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. A line of trees paralleled the runway on the southwest side of the runway, and a cornfield was on the northeast side. As the pilot taxied to the end of runway 13, he noted a significant crosswind from over the tree line. After a normal runup, he increased the engine to full power. Immediately after the airplane lifted off the ground it drifted to the right over the cornfield. The airplane “seemed to have too little power to climb” and it stalled, touching down in the field. The left main landing gear separated, and the airplane spun to a stop. The airplane’s left-wing spar was substantially damaged. The fuel tank remained intact and about 7-8 gallons remained inside. The spark plugs were removed from the engine and were consistent with normal operations. The engine rotated without binding, and thumb compression was established on all cylinders. A boroscope was used to examine the inside of the cylinders; the piston heads and cylinder walls exhibited normal operating wear signatures. The pressure vacuum line exhibited a crack near where it connects to the engine. The crack was not visible until the protective sleeve was removed from the line. The nearest weather reporting facility was located about 14 miles north of the accident airport. At 0952, wind was reported from 220° at 6 knots. At 1100, the National Weather Service Surface Analysis Chart depicted southwest winds at 5 to 10 knots.

Aircraft

Registration
N72DX
Reported as
Vining SD1 Minisport
Category
Airplane, amateur-built
Serial number
0194
Built
2017
Airframe hours
31
Engine
Hirth F23, 50 hp, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental light sport (Special)
Last inspection
Annual · October 25, 2020 · 7 hours before
Destination
4I3 · Mount Vernon, OH
Airport
0OH5 · Freeman Swank Farms Airport, runway 13, 3,002 × 100 ft, grass/turf
Equipment
Unknown

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
67
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Sport pilot
Seat
Single
Restraint
4-point
Flight hours
365 total · 29 in this make and model · 330 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
220° at 6 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
68 °F, dew point 45 °F
Altimeter
30.20 inHg
Observed at
KMFD, 14 nm away
METAR

Docket · 5

The files NTSB released with the investigation on June 21, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 8.7 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.