Five lights blinking in unison in line formation across NC sky.First and foremost, I don't believe in outer space aliens or UFOs. There is a logical explaination for what I saw. Problem is, I can't explain it so I'm in search of an explanation. Last night, Wednesday, July 16, 2014 around 21:30 I was smoking on my back deck when is saw an aircraft come over the tree line from the north east headed in a southwesterly direction, about 220 degrees. The aircraft was soon followed by a second, a third, forth and finally a fifth. All five aircrafts were traveling in the same direction in a straight line formation and at the same distance apart. What caught my eye was that all 5 aircrafts each admitted one flashing beacon light and all five beacon lights were flashing in unison.Before having children, I spent 5 years working at Charlotte Douglas International Airport. I've spent enough time around airplanes that I can identify them in the sky. Even at night I can recognise the navigation lights on the tail and wings and even see the lights coming from the passenger cabin. I know that the five aircrafts I saw were flying too close to be passenger commercial aircraft so the could have been mitary. Only problem is, even military aircrafts have navigation lights on the wings and tail, these aircrafts didn't have any. The beacon lights flashed very bright as if LED and the intemitance lasted about one second in between flashes. It was dark enough out that when the lights were in between flashes, no objects were visible from the ground. Also, no noise was heard, but we don't normally hear noise from aircrafts traveling at 30,000 feet. But, as stated before, the big thing that caught my eye was the fact that all five aircraft's beacon lights were flashing in unison. To my knowledge, it would be very difficult and time consuming to sincronise call five beacon lights on all five aircrafts.In disbelief at what I was seeing, I stepped inside and pulled my wife out to see these for herself. My wife currently works in the ground control tower at CLT and has nearly 20 years experience in aviation. Even she couldn't explain what we were seeing. She even called our 16 year old daughter outside for a look as well. She was immediately frightened and ran back inside, but she's a nieve child. We sat outside for over 5 minutes watching these flashing lights move across the sky. These aircrafts never changed formation, never changed speed or direction. I know that they were moving too fast and were too low to be stars or satellites, however they seemed to move slower than most commercial aircrafts do at cruising altitude Please help me to identify what I saw.