What happened
On June 10, 2000, at approximately 10:53 local time, a Piper PA-28-140, registration CS-AYL, was participating in the Iberian Air Rally 2000. The aircraft, carrying two pilots and one passenger, departed from runway 16 at the Chaves Municipal Aerodrome.
During the takeoff roll, the aircraft encountered a 9 km/h tailwind. Although the aircraft became airborne mid-runway, it struggled to establish a positive rate of climb. To avoid obstacles located at the end of the runway, the pilot maneuvered slightly to the right. However, due to the low altitude and a nose-high attitude that obscured forward visibility, the aircraft's left wing and landing gear struck medium-voltage power lines approximately 1.08 nautical miles from the runway centerline. The impact caused the aircraft to crash, resulting in three serious injuries and the total destruction of the aircraft.
The investigation
The GPIAAF investigation examined the aircraft's performance, the meteorological conditions, and the operational environment. Investigators analyzed the aircraft's weight and balance, noting that the load was slightly above the maximum limits. The investigation also reviewed the runway characteristics, noting a 1.2% upward gradient on runway 16.
Meteorological data indicated that the wind direction had shifted significantly from the southeast to the northwest, suggesting the presence of downdrafts caused by the terrain. Furthermore, the investigation looked into the rally organization, noting that while several aircraft had departed from the same runway earlier without issue, the wind conditions had changed in a way that favored the use of the opposite runway.