He pushed the plane as far as it would go on the gas he had, and used his last bit to climb for altitude. When he flamed out, he glided to land in Japan. Since the MiG-25 glides like a brick, this took HUGE, BRASS ones. Then, he followed up with a dead-stick landing at the Air Force Base (whose name escapes me), in bad weather.
The epilogue of the story was, the Russians demanded the return of their airplane. We complied, after stripping it down to individual BOLTS and packaging each one, labeling them, and sending them back. It took over a year...