On August 8, 2019, about 0845 mountain standard time, a Piper PA-30 airplane, N10KC, was substantially damaged when it was involved in an accident near Phoenix, Arizona. The flight instructor and student pilot were not injured. The airplane was being operated under the provisions of Title 14 Code of Federal Regulations Part 91 as an instructional flight. The flight instructor reported that, after completing a single engine approach and go around, he noticed that the landing gear would not fully retract. He added that, the landing gear circuit breaker was in the open position. The flight instructor reset the circuit breaker and attempted to cycle the landing gear but was unsuccessful, as every time the circuit breaker was reset, it would pop back to the open position again when the gear was cycled. He then attempted to manually extend the landing gear using the gear extension handle, which was also unsuccessful. Subsequently, he elected to land with the landing gear intentionally retracted. Postaccident examination of the airplane revealed damage to the lower fuselage caused by abrasion damage to the underlying structure. Two longitudinal keel beams sustained abrasive damage. According to a Federal Aviation Administration inspector who examined the airplane, he reported that when the nose gear was retracted, the centering mechanism was not able to center the nose gear, jammed, and prevented the nose gear from retracting. A mark was observed on the top of the nose gear fluted centering guide attached to the strut that was consistent with the nose gear being positioned to the far right. Once the nose gear landing assembly was positioned back to the normal position, no anomalies were noted during landing gear extension and retraction.