On Friday, April 23, 2004, approximately 1330 mountain daylight time, a Cessna 170B, N8252A, nosed over after exiting the side of the runway during landing at Nampa Municipal Airport, Nampa, Idaho. Neither the private pilot/owner, who was in the left seat, nor the airline transport pilot, who was in the right seat, were injured. The aircraft, which is owned and operated by the pilot in the left seat, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which had been in the pattern at Nampa for about 15 minutes, was being operated in visual meteorological conditions. No flight plan had been filed. There was no report of an ELT activation. According to the pilot in the left seat, who had purchased the aircraft the day prior to the accident, prior to the purchase he had no experience in this make and model airplane. He started the flight by making two takeoffs and two full-stop landings. He said that both of his takeoff rolls were uneventful, with no directional control difficulties, but during both landings he had problems keeping the aircraft heading straight down the runway, and the pilot in the right seat had to take control of the aircraft and bring it to a full stop. After those two landings, it was decided that the more experienced tail wheel pilot in the right seat would perform a takeoff and landing, during which the pilot in the left seat would keep his hands and feet on the controls in order to feel the control inputs made by the other pilot. According to the pilot in the right seat, who's flight instructor's certificate had expired in 1991, during the takeoff he experienced "some difficulty," but he was not sure if it was related to having the left seat pilot on the controls with him. Once he got in the air, he tested the brakes a couple of times, but could find no fault, and confirmed each had "plenty of pressure." He then made a landing, touching down near the centerline, and pulling the yoke to the "full back" position, while making sure the engine was at idle. Although the initial touchdown was uneventful, soon thereafter the aircraft veered to the right, and the pilot applied left rudder in an attempt to return it to the runway heading. Seeing that the application of rudder alone was not adequate, the pilot applied heavy left brake, but the aircraft continued to the right and exited the right side of the runway. As the aircraft exited the runway, the right seat pilot began applying right brake also, and soon thereafter the aircraft nosed over onto its back. The Federal Aviation Administration's post-accident inspection of the scene revealed a black skid mark on the runway surface created by the left main landing gear, and no indication of braking with right wheel until after the aircraft departed the runway surface. Inspection and testing of the aircraft did not reveal any indication that there had been a brake malfunction or any anomaly in the rudder/tail wheel steering system that would have created an uncontrollable situation. In an interview with the NTSB Investigator-In-Charge (IIC), the right seat pilot said that although he had about 25 hours in this make and model airplane, it had been "many years" since he had flown one.