Still in a shallow dive, I observed a P-51 and an Me 109 going round and round. It seemed that the 38 needed help so I started down. At about , the Jerry, still way out of my range, turned under me and slightly to the right. I rolled over on my back, following him and gave him an ineffective burst at long range. By this time I was traveling in excess of . My left window blew out, scaring the hell out of me. I thought I had been hit by some of the ground fire I had observed in the vicinity. I regained control of the aircraft and pulled out above a wheat field. I tried to contact the flight to get myself recognized, but observed an Me 109 making a pass at me from about seven o'clock high. I broke left as well as my plane could and the Jerry overshot. I straightened out and gave him a burst. He chandelled steeply to the left and I shot some more. He passed right over me and I slipped over in an Immelmann. As I straightened out at the top, I saw the pilot bail out.