What happened
On July 19, 2022, a Europa Classic monowheel aircraft arrived at the Airport of Kortrijk-Wevelgem (EBKT) from a farm strip in the United Kingdom. The flight was a non-commercial cross-country operation intended to continue to Kiewit-Hasselt after clearing customs.
During the landing roll on runway 06, the aircraft began to swing laterally. In an attempt to maintain the centerline, the pilot applied rudder input and braking. This combination of actions caused the aircraft to pivot 90 degrees, eventually tipping onto its left wingtip. The impact caused the propeller to break and resulted in scrapes to the lower cowling and left wing. The aircraft remained on the runway surface throughout the event, and the pilot escaped without injury.
The investigation
The AAIU(Be) conducted a data-collection-only investigation. The inquiry focused on the unique handling characteristics of the monowheel configuration and the environmental conditions at the time of the incident. Meteorological data indicated a light crosswind of approximately 6 knots from 130 degrees, which was nearly perpendicular to the runway heading.
Findings
- The aircraft's design features a single main wheel located in front of the center of gravity, which creates different ground handling dynamics compared to tricycle or conventional taildragger aircraft.
- Because the center of gravity is behind the single main wheel, the aircraft is susceptible to a "slingshot" effect where any turn tends to increase in magnitude.
- The pilot's simultaneous use of braking and rudder input exacerbated the directional swing.
- Friction or braking on the single main wheel increases the centrifugal force acting on the center of gravity, intensifying the tendency to ground loop.
Safety action
To prevent similar occurrences in monowheel aircraft, the following operational considerations were noted:
- Pilots should avoid heavy braking when the aircraft is nearing the edge of the runway, as braking is likely to induce a ground loop; instead, allowing the aircraft to run onto the grass may be safer.
- Applying power may be more effective than braking for regaining the runway heading.
- Maintaining consistent and significant pressure on both rudder pedals is critical for directional control in this aircraft type.