Incident Overview
On September 28, 1965, a Piper PA-28-180 Cherokee, registered as OE-DPS, was involved in an accident at Birrfeld Airfield in Aargau, Switzerland. The aircraft, operated by Otto Zwoboda Gesellschaft m.b.H., was on a Visual Flight Rules (VFR) journey from Geneva to Munich with two other similar aircraft. Due to deteriorating weather conditions, the pilot decided to make an intermediate landing at Birrfeld.
Operational Context and Weather
The pilot, an Austrian national with over 1,200 hours of flight experience, was leading a formation of three Piper PA-28s. The route encountered significant precipitation, with visibility dropping to as low as 2 km in some areas. At Birrfeld, the weather was characterized by light rain that intensified into heavy showers near the airfield. The runway was a 600-meter grass strip, with a main road located immediately at the western end, separated by a grassy slope and a paved curb.
Accident Sequence
While on the downwind leg, the pilot encountered a sudden heavy rain shower that obscured forward visibility. To maintain visual contact with the airfield, the pilot reduced power and executed a tight turn to align for landing. The aircraft touched down approximately 236 meters from the runway threshold at an estimated speed of 65–70 mph with full flaps deployed.
Upon touchdown, the pilot applied the foot brakes but found no effective braking action on the wet grass surface. Attempts to pump the brakes and use the handbrake also failed to provide sufficient deceleration. With the aircraft approaching the end of the runway, the pilot shut off the ignition and fuel supply. The aircraft rolled up the slope onto the main road, where the nose gear was unloaded by full elevator input. This caused the aircraft to jump over the road; the left main landing gear struck an earth mound on the opposite side, shearing off the gear and damaging the left wing.
Damage and Outcome
The accident resulted in no injuries to the pilot or passengers. The aircraft sustained significant damage, including a severed left main landing gear, a damaged left wing, a deformed right main gear, and minor propeller damage. Repair costs were estimated at approximately 40,000 Swiss Francs, representing about 50% of the aircraft's value. Minor agricultural damage occurred in the adjacent field, though the owner waived any compensation claims.