RAF Hercules XV193 was one of three Hercules aircraft engaged in formation and low-level navigation training over Scotland. Having completed the formation element of the sortie, the three aircraft separated for individual exercises, which, for the crew of XV193, included a simulated drop of a small cargo pack onto a dummy drop zone in a valley, eight miles north of Pitlochry. Having completed the simulated drop exercises and turned north to begin their egress from the drop zone, a rocky outcrop forced the crew to continue the left turn. After avoiding this obstacle, the crew elected to reverse their turn to enter the narrow valley of Glen Loch and regain the original route. In performing this manoeuvre, at low-level and low-speed, the aircraft stalled and crashed. CAUSE: “There were no eyewitnesses to the final moments of the flight, and the aircraft was not fitted with an Accident Data Recorder or Cockpit Voice Recorder. The Board of Inquiry’s investigation therefore remains conjecture; notwithstanding that specialist advice from various sources, including the Air Accident Investigation Branch of the Department of Transport and the aircraft manufacturer supports their findings. The investigation found that the cause of the accident was consistent with the aircraft having stalled at an altitude from which recovery was impossible.”