- Date
- June 21, 2026, 09:30 local (14:30 UTC)
- Place
- Alva, OK · KAVK - Alva Regional Airport
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Taxi
- Aircraft
- N618SAStephen Aberle Chipper CH-2A
- Defining event
- Taxi: Loss of visual reference
- Weather
- Visual (VMC) · Day
- Status
- Completed · report September 17, 2026
- Report
- Approved by Office Director
- Investigation class
- Class 4 - Basic report with no Prelim publish
- NTSB office
- Western Pacific Region
- Parties
- FAA - OKC FSDO
- FAA report
- 20260621006469A
- Case key
- 203234
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The pilot's decision to taxi the tailwheel-equipped airplane over uneven terrain while operating with limited forward visibility, which resulted in the left main landing gear entering a hole.
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.
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
The pilot reported that he landed the tailwheel-equipped airplane in a grassy area between the paved runway and taxiway, which he stated is common practice at the airport. After touchdown, the airplane’s tailwheel settled to the surface, reducing the pilot’s forward visibility. The pilot continued straight ahead before initiating a left turn to a service road. Before reaching the service road, the left main landing gear entered a hole in the uneven terrain, resulting in substantial damage to the lower fuselage. The pilot's decision to continue taxiing with limited forward visibility over uneven terrain prevented him from detecting and avoiding the hole. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
Aircraft
- Registration
- N618SA
- Reported as
- Stephen Aberle Chipper CH-2A
- Category
- Airplane, amateur-built
- Serial number
- 019
- Built
- 2018
- Airframe hours
- 16
- Engine
- Aeromomentum AM/13, 100 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Condition · April 29, 2026 · 16.1 hours before
- Departed
- PVT · Kiowa, KS
- Destination
- Same as departure
- Airport
- AVK · Alva Regional, runway 18/36, 2,100 × 50 ft, grass/turf
- Equipment
- ADS-B, Electronic multifunction display, Electronic primary flight display, Satellite tracking device
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
- 25
- Injuries
- None
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Medical
- Class 3, Without waivers/limitations
- Last flight review
- February 4, 2026
- Seat
- Left
- Restraint
- 4-point
- Flight hours
- 235.1 total · 3.1 in this make and model · 169.8 as pilot in command · 9.7 in the last 90 days · 2.2 in the last 30 days · 0.4 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 120° at 18 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 79 °F, dew point 64 °F
- Altimeter
- 29.74 inHg
- Observed at
- KAVK
- METAR
- METAR KAVK 211435Z AUTO 12018KT 10SM CLR 26/18 A2974 RMK A01
Docket · 2
The files NTSB released with the investigation on September 17, 2026, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.0 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.