What happened
On July 19, 1963, a Beagle E 3 (registration G-ASCC) was conducting pattern work at Bern-Belpmoos airfield for the purpose of pilot type conversion. The flight, involving two experienced pilots, consisted of several landing attempts. During the initial landings, the aircraft demonstrated a consistent tendency to veer toward the left, requiring the pilot to apply right-side braking to maintain the centerline.
Following a successful fourth landing at approximately 09:1s, the pilot signaled to continue the pattern. However, while the second pilot was adjusting the flap settings, the aircraft began to swing left again. The pilot attempted to correct this by applying the right brakes. During this corrective maneuver, the aircraft suddenly swerved approximately 90 degrees to the right. This abrupt movement caused the tailwheel to lift off the ground, leading the propeller tips to strike the runway surface.
There were no injuries to the occupants during the event.
The investigation
Investigators examined the mechanical condition of the aircraft and the runway environment. The weather at the time of the incident was clear, cloudless, and calm with no wind and 10 km visibility. The accident occurred on the paved runway at the airfield.
Technical inspection of the braking system revealed an imbalance in wheel rotation. When rotated manually, the right wheel spun freely for several revolutions, whereas the left wheel moved only a fraction of a turn. This indicated that the left wheel had significantly higher resistance or drag than the right.
Findings
- The primary cause of the sudden rightward swerve was excessive braking applied during the attempt to correct the initial leftward drift.
- The aircraft exhibited a natural tendency to wander or swing during the landing rollout, likely due to the characteristics of the unsteered tailwheel.
- A disparity in braking resistance existed between the wheels, as the left wheel exhibited much higher drag than the right wheel, contributing to the initial leftward deviation.