Was sitting on eastbound elliot off ramp from interstate 10 first in line to turn eastbound elliott. Was warching jet take off from sky harbor airport heading due east when a flat saucer shaped moved beneath the jet moving west then abruptly stopped and reversed direction 180 degrees, at a high rate of speed. It then dropped several hundred feet and was hovering for a few seconds then moved west, stopped again and turned due east and was moving quickly and then disappeared.
As no right turns are allowed on red lights at this exit ramp, I could concentrate on what I was watching.
The object was very wide or long and a number of miles away. I could not judge whether or not it was in the take off corrider for commercial jet take offs or further north. Is was to far away to take a photo using a cell phone.
I also witnessed a large white aircraft at very high altitude showing a contrail for approx 5 seconds then on and off etc at regular intervals. It was completely different than the “donut” contrails I have seen a number of times in the metro phoenix skies. It appeared to be a single engine aircraft moving at a rate of speed that was not unexpected. It happened mid after noon tuesday movung south to north. There were few clouds in the area at that time. While not truly a ufo it did display a very unusual contrail never seen before. Jet noise could be heard but very faintly and could have been from a commercial airliner in the area. Positionwise I would estimate it parrelling between 40 street and interstate 10. I saw this from my back yard but did not have the opportunity to take a pic or video.