On February 25, 2009, about 1617 central standard time, a Cessna 172S airplane, N5258Y, piloted by a private pilot, and a Cessna 172N, N734WD, piloted by a student pilot, collided during taxi operations at Johnson County Executive Airport (OJC), Olathe, Kansas. Neither the private pilot or passenger in the 172S or the student pilot in the 172N were injured. The 172S received minor damage and the 172N was substantially damaged. Both personal flights were being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 without flight plans. Visual meteorological conditions prevailed at the time of the accident. Both local flights were originating at the time of the accident. The 172S airplane was occupied by a private pilot and a non-rated passenger. The private pilot received clearance to taxi from the tower controller and proceeded from the east parking ramp south on taxiway Bravo to taxiway Juliet. Taxiway Juliet crossed runway 18/36 and connected to taxiway Alpha. At taxiway Juliet, the private pilot was instructed to hold short of runway 36 for arriving traffic. After receiving clearance, the private pilot crossed the runway. When the 172S was approaching the intersection of taxiway Juliet and Alpha, the pilot diverted his attention to the run-up area of runway 36 to observe how many airplanes were performing run-ups. As he started the turn, the 172S impacted the left side of 172N. Neither the private pilot or his passenger reported seeing the 172N prior to impact. The 172N was occupied by a solo student pilot. The student pilot had completed a dual instruction ride and landed on Runway 36. She taxied clear of the runway on a midfield taxiway, where air traffic control (ATC) transcripts show she requested and received clearence to taxi to Runway 36 via Taxiway A. She then stopped on the taxiway and her certified flight instructor (CFI) got out of the airplane to allow her to continue for a solo flight. The tower controller contacted her and informed her the CFI could not exit the airplane on the taxiway. The CFI returned to the airplane and the 172N was cleared by the tower controller to taxi to the parking ramp. The student pilot then taxied north on Taxiway A to the west parking ramp. The student pilot reported that her CFI informed her that she "was clear to continue up the taxiway." The CFI deplaned and the student pilot taxied south on taxiway Alpha without obtaining a new taxi clearence from the tower controller. She said she saw 172S on the connecting taxiway prior to impact, but thought it was going to stop. According to FAA investigators, there was a single tower controller on duty at the time of the accident. He was not aware the 172N was taxiing south on taxiway Alpha and was following aircraft activity on a different area of the airfield at the time of the accident. Examination of the 172N revealed a propeller strike to the left wing spar, a bent left horizontal stabilizer, and a bent fuselage tail cone.