What happened
On January 18, 2003, two Piper PA-18 aircraft were conducting independent operations on the Rosa-Blanche Glacier near Nendaz, Switzerland. The first aircraft, HB-ORK, was conducting a flight training session involving an instructor and a student pilot, performing a series of touch-and-go landings. The second aircraft, HB-ORN, was carrying a pilot and a passenger on a flight from Annemasse to Sion.
Both crews were communicating their intentions via radio on the local mountain flight frequency. Initially, the aircraft operated in sequence, maintaining safe distances while using the upper portion of the glacier. However, the situation changed when the pilot of HB-OR decided to land on the lower section of the glacier. Simultaneously, the crew of HB-ORK began their third takeoff from the upper section of the glacier, heading toward the lower area.
As HB-ORK accelerated toward the lower glacier, it encountered HB-ORN during its final approach. Due to the high relative speed and the loss of visual contact between the two crews, the aircraft collided at the level of their right wings. The impact resulted in two serious injuries for the occupants of HB-ORK, while the occupants of HB-ORN remained unharmed.
The investigation
The investigation examined the operational procedures, technical condition of both aircraft, and the environmental factors at the site. Investigators found that both aircraft were technically sound, with no mechanical failures contributing to the event. The aircraft were properly equipped for mountain operations, and all weight and balance parameters were within limits.
The inquiry focused on the communication and coordination between the two crews. It was noted that the topography of the glacier makes it difficult to maintain a full view of the landing area when operating on different sections of the slope. The investigation also reviewed the radio transmissions and the sequence of the takeoff and landing maneuvers.