Background
The Piper PA-28-181, registered as HB-PHB, was owned by the Fluggruppe Pro Altenrhein. It departed St. Gallen-Altenrhein, Switzerland, on 19 September 2005 on a ferry flight to El Beriel, Gran Canaria, with multiple pilots alternating legs. A flight instructor remained on board throughout. The aircraft arrived at Marrakech, Morocco, on 1 October 2005 at 13:15 UTC, flown from the left front seat by Pilot A, with the instructor in the right front seat and Pilot B as a passenger. After landing, the tanks were filled to approximately 128 litres (34 US gallons) of AVGAS 100 LL.
On 2 October, Pilots A and B were not flying; the instructor conducted a local flight with Pilots C and D, who had joined the crew in Marrakech. On 4 October, the aircraft departed Marrakech at 06:35 UTC for a visual flight to Ouarzazate, with Pilot C at the controls and the instructor occupying the right front seat. Pilot D was seated in the rear.
Accident Sequence
The flight path from Marrakech to Ouarzazate followed approximately a straight line. The aircraft entered a valley south of Azgour that ascended eastward around 07:08 UTC. Shortly thereafter, it collided with the north-facing side of the valley. The accident occurred at about 07:10 UTC. The aircraft was destroyed and all five occupants sustained fatal injuries.
Aircraft Information
The aircraft was a Piper PA-28-181, a single-engine four-seat light aircraft. The investigation found no pre-existing technical defects; the engine and instruments were examined and showed no anomalies. The aircraft's performance was limited by its high mass and the density altitude, which was elevated due to the mountain environment.
Meteorological Conditions
At the time of the accident, the weather conditions included a low sun angle that made it difficult for the crew to assess the flight path relative to the terrain. The specific weather at the accident site is not detailed beyond the general conditions. The sun position was noted as quite low.
Findings
The accident was determined to be a collision with terrain. The crew chose a flight altitude that, given the narrow valley and prevailing weather, did not allow for a turn or a safe crossing of the lowest ridge. Contributing factors were the crew's unfamiliarity with the characteristics of the High Atlas, the aircraft's reduced climb performance due to high mass and density altitude, and impaired visual assessment of the terrain due to the low sun.