The airplane was approaching Davis Monthan Air Force Base in Tucson Arizona at approximately 4:15PM MST on August 8th, 2009. We first witnessed the object hovering in a locked position, southwest of the base. You can hear my neighbors if you turn the volume up. We thought it was a balloon, until it dropped in elevation a few thousand feet in less then a second. At that point I ran inside and grabbed my digital camera and rushed outside in time to catch the object approaching the airplane from behind. Unfortunately the microphone barely works on the camera, from being dropped so many times, so you can't hear much. But at least there is a little. The object made no sound, completely silent.