On January 15, 1997, at 0841 hours mountain standard time, a Piper PA-18-150, N4101E, ground looped during the landing ground roll at the Chandler, Arizona, airport. The aircraft was operated by Chandler Air Service and was engaged in a dual instructional flight familiarizing the student with conventional landing gear aircraft. Visual meteorological conditions prevailed at the time and included light and variable winds of less than 2 knots. The aircraft incurred substantial damage to the left wing. Neither the commercial pilot/flight instructor nor the private pilot under instruction were injured. The flight originated at Chandler on the day of the accident at 0745. The flight instructor stated in his written report that on rollout from a touch-and-go landing the student looked down for the flap handle as he raised the flaps. During this process the aircraft started to go to the right. He noted that "I tried to correct to the left using rudder and aileron, then also using power, but the plane ground looped to the right and the left wing dipped, striking the ground." Additionally, the pilot indicated that there were no mechanical malfunctions with the aircraft prior to the accident. The aircraft had accumulated 36 hours over a 3 week period since the last 100-hour inspection was performed.