What happened
On September 8, 2016, at approximately 19:08 UTC, a Robinson R611 helicopter was performing a night flight from the Elberfelder Hütte toward Salzburg. The pilot had previously flown to the mountain hut earlier that day to deliver supplies. Following a stay at the hut, the pilot decided to return to Salzburg, intending to climb to 1,000 feet to avoid terrain obstacles.
During the departure, the pilot noted that a portable navigation device was displaying no signal, though they proceeded with the flight. After taking off and performing a 180-degree turn, the pilot directed the aircraft toward the valley exit. As the helicopter progressed, the passenger observed rocks and boulders appearing within the beam of the landing light. The pilot subsequently applied significant nose-up cyclic input, causing the aircraft to collide with the rocky ground at an altitude of approximately 2,358 meters.
The accident resulted in one fatality and one serious injury.
The investigation
The Austrian SUB investigated the wreckage and the circumstances surrounding the flight. The investigation examined the aircraft's maintenance history, which showed the helicopter had undergone a 100-hour inspection shortly before the accident. The engine, fuel system, and flight controls—including the main and tail rotor controls—were all found to be in proper working order with no evidence of pre-existing technical failures. The aircraft's weight and balance were also within permissible limits.
Investigators also analyzed the environmental conditions, noting that civil twilight had ended at 18:07 UTC. The night provided very low natural light, and there were no artificial light sources available in the valley or at its exit to assist with navigation.
Findings
- The primary cause of the accident was a loss of orientation during the flight.
- The use of the landing light in combination with undimmed instrument lighting likely created a significant glare for the pilot.
- The lack of natural light and the absence of external light sources in the valley made maintaining visual orientation extremely difficult.
- The pilot had only approximately 2.2 seconds to react to obstacles appearing within the 60-meter range of the landing light beam while traveling at approximately 53 knots.