A CATA Fairchild FH-227B (LV-MGV) was involved in a ground collision with an American Airlines Boeing 777-223ER (N759AN) at Buenos Aires/Ezeiza Airport, BA (SAEZ) After completing a flight from Jorge Newbery Airport, the pilot of the FH-227B proceeded to park the aircraft in front of the company hangar. The parking maneuver was performed without the assistance of a marshaller because this parking position is considered a remote location where each user must provide their own services. While turning to park, the upper end of the vertical stabilizer and the rudder made contact with the right wingtip of the Boeing 777 aircraft, which was parked while being prepared for a flight. The accident occurred during daylight hours, and weather conditions did not contribute to the incident. CAUSE: During the parking maneuver, collision of the vertical stabilizer and rudder with the right wingtip of a parked aircraft due to an error in calculating the turning radius. Contributing factor: Parking without the assistance of a marshaller.