According to the pilot, the landing approach and the touchdown were normal. Shortly after touchdown, the airplane began to turn to the left, and the pilot corrected the turn by applying right rudder. The airplane then corrected to the right, however, the pilot stated he "must have held right rudder too long resulting in the aircraft ground looping to the right. The only cause [pilot] can attribute to the ground loop was pilot error." During the ground loop, the left wing contacted the ground, damaging the spar.