What happened
On May 1, 1967, a Beech A23-24 Musketeer Super III, registration HB-ENW, was performing a private flight from Reichenbach im Kandertal to Bern. During the approach to Bern Airport, the pilot encountered significant wind conditions, with gusts reaching 20 to 30 knots from the west. After an initial attempt to land on the main runway was disrupted by a strong rightward drift caused by the wind, the pilot accepted a suggestion from the tower controller to land across the airfield, approaching from the east to take advantage of the wind direction.
The aircraft touched down on the grass runway approximately 305 meters past a military hangar. Following the touchdown, the pilot deployed the wheel brakes and retracted the flaps; however, the aircraft failed to decelerate sufficiently on the wet grass. The aircraft bounced four times before coming to a rest approximately 200 meters further down the field. Unable to stop before reaching the edge of the airfield, the aircraft crossed a secondary road and struck a dam at a 45-degree angle.
The investigation
The investigation examined the pilot's flight experience, the aircraft's mechanical condition, and the meteorological circumstances. The aircraft, which had fewer than 100 hours of total operating time, was found to be in excellent condition with its weight and center of gravity within limits. The investigation also noted that while the pilot had recently completed training on this specific model, the formal documentation had not yet been updated in his license.
Investigators analyzed the landing technique and the approach path relative to the airfield's obstacles. The study focused on why the aircraft could not be brought to a halt before the perimeter boundary and the impact of the wind on the approach stability.
Findings
- The primary cause of the accident was an inadequate landing tactic that resulted in a landing roll that was too long to safely stop the aircraft.
- The pilot's approach path over the military hangar was unnecessarily high, which reduced the available landing distance and increased the difficulty of the maneuver.
- The use of insufficient flap settings (only 10 degrees) contributed to the aircraft maintaining a higher speed during the landing phase.
- The wet surface of the grass runway significantly reduced the effectiveness of the wheel brakes.
- The pilot failed to follow the manufacturer's recommended procedures for obstacle-clearing landings, likely causing the nose to dip and increasing the landing speed.