On Saturday, March 14, 1998, approximately 1555 hours Pacific standard time, a Cessna 152, N757CZ, registered to Paul M. Etchemendy, being operated by Eagle Flight Center, Inc., and being flown by a student pilot, incurred substantial damage when the pilot executed an off-airport landing during which the nose landing gear collapsed and the aircraft nosed over in a field near the McMinnville airport, McMinnville, Oregon. The pilot was uninjured. Visual meteorological conditions existed and no flight plan had been filed. The flight, which was an instructional solo, was to have been operated under 14CFR91, and originated from Hillsboro, Oregon, approximately 1520. The student pilot reported that he began his first approach to runway 22 at the McMinnville airport and retarded the throttle passing the abeam position. He noted that the RPM remained at 2,000 and was unable to increase or decrease RPM with full throttle movement. The pilot radioed the airport on CTAF frequency and declared an emergency, lowered full flaps and continued his approach to runway 22. The aircraft touched down approximately midfield and the pilot did not attempt to shut down the engine (mixture, fuel selector or ignition OFF). As the aircraft continued to roll he became apprehensive about his ability to stop before the end of the 5,419 foot long runway. Running out of usable runway, the pilot then initiated a go-around. Unable to obtain more than 2,000 RPM power in the go-around, the pilot maneuvered the aircraft to clear trees, adjusted his angle of bank to avoid a stall, and then raised the flaps to increase climb performance. When he heard the stall warning horn, and with an open field ahead, he then attempted to re-land the aircraft, again facing the same difficulties in stopping the aircraft as on the paved runway. And again, the pilot did not attempt to shut down the engine (mixture, fuel selector or ignition OFF). As the aircraft rolled and bounced across the field, the nose landing gear entered an area of soft terrain, dug in and then collapsed. The aircraft then nosed over. On site examination by an FAA inspector revealed the throttle cable had become disconnected at the throttle-to-carburetor adapter plate on the carburetor throttle arm. The bearing end of the throttle rod, as well as one of its retaining nuts, was absent, as was the bolt which passes through both the rod-end bearing, and the carburetor adapter plate. All three washers on this bolt, as well as its associated nut and cotter key, were also absent (refer to DIAGRAM I). The missing hardware was never found. An inspector from the FAA's Flight Standards District Office (Hillsboro, Oregon) examined the aircraft's logs and reported that a 100 hour inspection had been conducted on the aircraft on January 10, 1998, at a total time of 6470.4 hours. The log further showed that on March 5, 1998, the throttle control cable was removed and replaced with a new unit at a total aircraft time of 6488.6 hours. This maintenance was signed off in the aircraft's airframe log by the owner, a certificated airframe and powerplant mechanic. The Operator reported that the aircraft was flown approximately five times following the new cable installation and prior to the sixth (accident flight). The aircraft total time at the accident site was 6494.0 hours. The student pilot reported a total of 51 hours of flight experience (all within the 90 days previous to the accident). He also reported more than 45 hours in the Cessna 152.