On March 16, 2003, at 1715 central standard time, a Piper PA-28R, N7635J, registered to and operated by Double Bridges Aviation LLC, collided with the ground during an emergency landing three miles southwest of Enterprise Municipal Airport, Enterprise Alabama. The instructional flight was operated under the provision of Title 14 Part 91. Visual weather conditions prevailed at the time of the accident. No flight plan was filed. The airplane sustained substantial damage. The certified flight instructor and student pilot were not injured. The flight departed Enterprise Municipal Airport, Enterprise Alabama on March 16, 2003, at 1545. According to the student pilot, while simulating an emergency descent, there was a surge in engine rpm and a significant drop in engine oil pressure. The CFI checked the engine oil pressure and within seconds the engine seized, and by this time the windshield was covered with oil. The CFI diverted to an open wheat field three miles southwest of Enterprise Municipal Airport. During the emergency landing, the airplane touched down but became difficult to control after rollout and the airplane spun 120 degress to the right, colliding with the terrain. Examination of aircraft found that the propeller assembly was bent, all three landing gear had collapsed and both wings were damaged in the vicinity of the collapsed landing gear. There was also damage to the fuselage just aft of the baggage compartment. Examination of the engine revealed that there was a crack in the propeller governor external oil line located at the first 90-degree bend radius aft the forward B-nut. A review of the aircraft maintenance log disclosed that the oil line was installed about 30 hours before the accident.