NORAD confirmed that on the 25th of October 2017 the scrambled F-15 fighter jets to intercept a mysterious aircraft that was flying in daylight hours between the steady stream of airliners that traverse from south to north, between locales in California and Nevada and cities like Portland and Seattle and beyond. The mysterious aircraft could be tracked by ground radar, but was not emitting any transponder signals. It also did not react to airtraffic control calls.
Airtraffic control asked several commercial airline pilots to give a visual confirmation of the object and in what direction it was heading. After a while NORAD scrambled several F-15 figher jets to intercept the mysterious aircraft, but when they arrived on the coordinates that were given, they were not able to find it. Today the official airtraffic control audio was released. The conversations between ATC and the commercial pilot clearly show that this object was clearly visible.