This sighting occurred on a summer evening, just before dark in the early 70s. I was in my early/mid teens, and we lived in rural Greene Co, between Xenia and Beavercreek, Ohio. At the time the area was all farm land with just a smattering of old farm houses, including our home. My younger brother and I were in our back yard when I noticed a USAF C-119 transport approaching Wright-Patterson AFB (10 miles away) from the east. (I assume the aircraft was one from Clinton County AFB near Wilmington, Oh where an Air Force Reserve C-119 unit was based at the time. C-119s were very common sights in the area as a result.) The aircraft was probably at 2000-3000 ft, flying at around 150 mph. As I watched I saw a brilliant light, quite small and very well defined, streak into view from overhead (approximately 30 degrees from the vertical from a southwestwardly direction) heading directly towards the transport. For the next 15-20 seconds, the light darted around the C-119 at very high speed, performing sharp maneuvers flying above, below and around the aircraft. The light then sped off in the same direction from which it came, although climbing at a significantly shallower angle than it arrived. Within seconds it was out of sight. Total time the light was in sight was less than 30 seconds. During the encounter, there was no sound other than the piston engines of the transport. The C-119 did not appear to take any evasive action, meaning either the crew didn’t see the light or made a conscious decision not to evade. The C-119 continued towards WPAFB, where I assume it landed. I specifically remember watching the local news for the next few days, and reading the local newspapers to see if the incident was reported. It was not uncommon for UFOs to be reported on TV and in the newspapers of the day, but no mention of the light I witnessed was reported by local media..