What happened
On December 23, 1972, a Beechcraft 60 (registration HB-GER) was conducting a private flight from Basel with an intended destination of Neuchâtel. During the flight, the pilot encountered unfavorable weather conditions near Berne and decided to divert to La Chaux-de-Fonds, an airfield not originally listed as an alternate on the flight plan.
Upon arriving at La Chaux-de-Fonds, the pilot was unfamiliar with the local procedures. Unaware that the traffic pattern for runway 06 was a right-hand circuit, the pilot entered a left-hand pattern. A communication misunderstanding with the tower prevented the correction of this error. During the base turn, the aircraft lost visual contact with the runway due to nearby terrain, resulting in an approach characterized by excessive altitude and airspeed.
The pilot performed a three-point landing near the middle of the runway, which was partially covered in patches of ice. Despite applying heavy braking, the aircraft could not be stopped within the available distance. The aircraft exited the runway and came to rest in 20 cm of snow approximately 15 meters beyond the pavement. The impact caused the nose gear to collapse and resulted in significant damage to the engines, propellers, and fuselage. The pilot escaped the wreckage uninjured.
The investigation
Investigators examined the aircraft's technical status, finding all airworthiness certificates were valid and no mechanical failures contributed to the accident. The aircraft's weight and center of gravity were within prescribed limits.
The investigation focused on the pilot's approach and the runway conditions. While the weather was clear, the runway surface contained icy patches. Analysis of the landing showed that the aircraft crossed the runway threshold at an altitude of approximately 17 meters and at a speed exceeding the ideal approach speed of 87 knots. Given the aircraft's weight and the specific runway gradient, the required landing distance was calculated to be approximately 810 meters, exceeding the 755-meter usable runway length.
Findings
- The primary cause of the accident was excessive speed and altitude during the final approach, which made a runway overrun inevitable.
- The pilot's lack of familiarity with the La Chaux-de-Fonds traffic pattern led to an incorrect circuit entry.
- The diversion to an unplanned airfield meant the pilot was insufficiently prepared for the specific characteristics of the aerodrome.