The pilot had just finished making some practice passes for night fighters when he spotted an orange light to the east of his plane. He checked on aircraft in the area, learned that the object was unidentified, and started after it. Here is his report, written immediately after he landed: As it [the light] approached the city from the east it started a left turn. I started to intercept. During the first part of the chase the closest I got to the light was 8 to 10 miles. At this time it appeared to be as large as an SNJ and had a greenish tail that looked to be five to six times as long as the light's diameter. This tail was seen several times in the next 10 minutes in periods of from 5 to 30 seconds each. As I reached 10,000 feet it appeared to be at 15,000 feet and in a left turn. It took 40 degrees of bank to keep the nose of my plane on the light. At this time I estimated the light to be in a 10-to-15-mile orbit. At 12,000 feet I stopped climbing, but the light was still climbing faster than I was. I then reversed my turn from left to right and the light also reversed. As I was not gaining distance, I held a steady course south trying to estimate a perpendicular between the light and myself. The light was moving north, so I turned north. As I turned, the light appeared to move west, then south over the base. I again tried to intercept but the light appeared to climb rapidly at a 60- degree angle. It climbed to 35,000 feet, then started a rapid descent. Prior to this, while the light was still at approximately 15,000 feet, I deliberately placed it between the moon and myself three times to try to identify a solid body. I and my two crewmen all had a good view of the light as it passed the moon. We could see no solid body. We considered the fact that it might be an aerologist's balloon, but we did not see a silhouette. Also, we would have rapidly caught up with and passed a balloon. During its descent, the light appeared to slow down at about 10,000 feet, at which time I made three runs on it. Two were on a 90-degree collision course, and the light traveled at tremendous speed across my bow. On the third run I was so close that the light blanked out the airfield below me. Suddenly it started a dive and I followed, losing it at 1,500 feet. In _this_ incident the UFO _was_ a balloon. The following night a lighted balloon was sent up and the pilot was ordered up to compare his experiences. He duplicated his dogfight-- illusions and all. The Navy furnished us with a long analysis of the affair, explaining how the pilot had been fooled. In the case involving the ground observer and the F-47 near the atomic installation, we plotted the winds and calculated that a lighted balloon was right at the spot where the pilot encountered the light. In the other instance, the "white object with two windows," we found that a skyhook balloon had been plotted at the exact site of the "battle."