What happened
On 8 September 2015, a Piper PA-28-181, registration D-ELMN, was operating a private visual flight from San Luis aerodrome in Menorca toward La Cerdanya aerodrome in Girona. The aircraft was leading a three-plane formation, with two other light aircraft following in sequence.
As the formation approached the destination, the aircraft was flying through a valley in the municipality of Toses. Video footage recovered from a trailing aircraft showed the D-ELMN flying at a very low altitude relative to the terrain. While navigating the valley, the aircraft initiated a left turn and struck trees on the left slope of the mountainside. The impact caused the left wing to detach, and the aircraft continued to rotate and fall in an inverted position. The subsequent impact with the ground triggered an explosion and a fire that destroyed the aircraft. Both the pilot and the passenger sustained fatal injuries.
The investigation
The CIAIAC investigation examined the wreckage, meteorological data, and statements from the other two pilots in the formation. Investigators analyzed footage from a camera mounted on the second aircraft, which captured the final moments of the flight. The investigation also reviewed the aircraft's maintenance records, which showed the plane was in good condition, and its load and balance, which were within manufacturer limits.
Meteorological analysis indicated that while visibility was good, there was evidence of convective clouds and potential turbulence in the area. The investigation focused on the flight path and the altitude maintained by the lead aircraft relative to the surrounding mountain peaks.