2001-06-24 - Mesa, AZ - Unknown

At approximately 10:31 am, Sunday morning, I was outside on our back porch smoking a cigarette when a flight of three Air Force trainer jets (T3's or T4's? The ones that look like F5's) flew nearly overhead of my location in East Mesa. Unusual but I've never seen trainers here before. They flew in a tight formation, north to south, at an estimated altitude of 5000 ft, disappearing from view in approx. 2 minutes. Although the speed must have been nearly supersonic, at the capacity of military power(without afterburner) the engine noise was really quiet...less than a Lear jet cruising. Falcon Field airport is a few miles away, I've seen plenty company jets. Williams Gateway airport is a few miles south, and Chandler Municipal Airport a bit south of that...I believe all have radar. As the aircraft diminished to a dot on the southern horizon I noticed what at first I thought was a vulture riding the thermal air currents just to my south, between the jets and my location. We see that all the time out here. My assumption was short lived. What I witnessed behind the trio of trainers I thought to be a large bird in the distance playing in the thermals--a thick, short horizontal line moving back and forth, then in lazy circles, above the clouds then below, behind a tree then behind a house then vertical. The object moved like a balloon on the wind but had the flat appearance of the thicker edge of a matchbook held at about 15 feet. The object vanished into a cloud bank about 90 seconds after the jets faded from view, south of my location, slightly east of the trainer formation. From the time I lit a cigarette and the jets flew over to the end of the sighting was less than the time it took for me to finish my cigarette. There was no metalic reflection, just flat black. The distance was too great to discern shape, but it wasn't a bird, nor conventional aircraft. But it could have been military.