What happened
On September 18, 1985, an Italian student pilot was conducting a solo cross-country training flight in a Cessna F152 with registration HB-CNX. The operation was part of private pilot license instruction, specifically a navigation exercise authorized under his student pilot certificate. The aircraft was operated by Aero Locarno SA.
The flight plan involved multiple legs starting from Locarno to Sion for refueling, then proceeding toward Lugano via Brig and the Novena Pass. The student had prepared detailed VFR navigation plans for each segment, which were reviewed by his instructor. He departed Locarno at 1108 local time and landed in Sion without incident.
After refueling, he departed Sion at 1345 toward Lugano. Approximately 20 minutes after crossing the Novena Pass, the pilot realized he could not identify the expected villages of San Carlo and Maggia. Instead, he observed a military airfield. Realizing he had made a significant navigational error, he attempted to correct his course by flying north-northeast. However, total disorientation set in. He eventually believed he was near Domodossola and decided to perform a precautionary landing near a large mountain village.
He selected a slightly uphill, obstacle-free field approximately 1.5 km southwest of Spluga. Upon touchdown, the aircraft bounced over a terrain undulation and settled into a depression about 10 meters later. Unable to clear the subsequent rise in the ground, the Cessna F152 HB-CNX flipped over and came to rest inverted. The pilot sustained fatal injuries.
The investigation
The Swiss Transportation Safety Investigation Board (SUST) examined the flight preparation, meteorological conditions, aircraft status, and the pilot's mental state. Key findings included:
- The flight preparation was deemed adequate. The route was clearly marked on the ICAO map, which was folded to keep the active leg visible.
- No technical defects were found in the aircraft, and weight and balance were within limits.
- Meteorological conditions did not contribute to the accident.
- Post-accident reconstruction flights with the instructor revealed specific navigational errors: the pilot confused the Furka Pass with the Novena Pass, the St. Gotthard Pass with San Giacomo Pass, and Bellinzona with Domodossola.
- The shoulder harness was fastened at the time of impact.
Findings
The primary cause of the accident was total loss of orientation by the student pilot during the solo navigation segment. This resulted from misidentifying key geographical landmarks and passes in the Alpine terrain. The complexity of navigating south of the Alps for Ticino-based students, who are prohibited from crossing international borders during training, creates inherent navigational challenges that can overwhelm less experienced pilots.
Safety action
The SUST recommended that all military airfields be included in the ICAO map sheet 2253-B (Switzerland, 1:500,000). The board argued that listing these fields would enhance safety by alerting pilots to potential hazards and providing reliable navigation references, particularly in mountainous regions where navigation is difficult. They noted that military airfields are already listed on foreign maps, so omitting them from Swiss charts primarily disadvantages pilots operating within Switzerland.