Accident Information
On 30 March 1972 at approximately 16:30 local time, a Piper PA-18A aircraft, registration CS-ADE, operated by A. Douwens, was engaged in agricultural spraying operations near Herdade do Monte Branco do Roxo, Aljustrel, Distrito de Beja, Portugal. During a turn to reposition for a new row, the aircraft entered a spin and impacted the ground. The pilot was killed and the aircraft was totally destroyed.
Investigation
The accident site was located in an unobstructed, ploughed field. The engine was buried in the soil, and the cockpit was completely destroyed. Fractures in tubing, longerons, and hinges showed evidence of torsion, compression, and tension. The impact attitude was estimated at approximately 60 degrees, and wreckage was concentrated at the point of impact. Engine controls, electrical contacts, and fuel were in the ON position.
A witness who was working in the area reported that the aircraft was at an altitude of about 30 meters when a cracking sound was heard, followed by the aircraft falling. Weather conditions were good at the time.
The general attitude of the aircraft upon impact was consistent with a spin entry. The position of the controls, contacts, and selectors suggested the spin was unintentional.
Pilot Information
The pilot held a valid pilot license and qualifications necessary for the agricultural operations being conducted. According to records from the RIPN archive and operator information, the pilot had a total flight experience of approximately 1,500 hours, including about 400 hours in agricultural work. In the three months prior to the accident, the pilot had logged 102 hours in agricultural flights, and approximately 3 hours and 30 minutes on the day of the accident.
Aircraft Information
The aircraft held a valid certificate of airworthiness and was properly registered. For the last flight, the aircraft carried approximately 250 liters of Bihedonal (MCPA+24D) product and an estimated 30 to 50 liters of fuel. Weight and balance were calculated to be within limits.
Probable Cause
The investigation commission determined the probable cause to be undetermined.