Glowing Disk Over Phoenix, Aliens Working With USAF, Arizona On Dec 29, 2015, UFO Sighting News.

Date of sighting: December 29, 2015
Location of sighting: Phoenix, Arizona, USA
Source: MUFON #73480

The persons assumptions about this being a secret craft from Luck Air Force Base may be right on. The base is in Phoenix and is known for UFOs to frequently be seen along its mountains, often with a jet escort, which could mean its a USAF craft, or it could be an alien craft incoming that works at the base. The USAF have sectioned off some land within some of their bases in Arizona, Nevada area that is off limits to all military personnel. It keeps alien and humans from mixing. For instance, the aliens called the tall whites at Nellis AFB
Scott C. Waring

Eyewitness states:
From my driveway, looking northeast above South Mountain, I observed a flying object that did not look at all like a commercial airliner. It was 1-2 miles away, headed slowly northeast. The reddish-orange lights ran completely across the midsection, and pulsated. I quickly took pictures with my smartphone camera, and tried to get a video, but streetlight came on, which made video impossible. I was returning from the store and happened to look in the sky, and noticed immediately that this didn't look like a "normal" aircraft. My first thought was "not a normal plane, get a picture". Given the proximity to airforce bases and previous unidentified aircraft around Phoenix, I thought it might be some new experimental craft, or maybe one not of this planet. My feeling was "Hey, I'm really seeing this, and it isn't spooky or overly exciting -- this is a real craft of some type". No emotion swings, just logical realization that I'm seeing something outside my frame of reference. I lost sight of it when it was 5+ miles away, and was too small to see in the dark night sky.