Light Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Distraction; Situational Awareness
Airspace Violation All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Aircraft; Airspace Structure; Environment - Non Weather Related
During the arrival into DEN; we saw; at close distance; what appeared to be a UAS (unmanned aerial system) on approach.  I was PIC and Pilot Flying on this passenger trip. We were about 7 min from landing. During the arrival there were thunderstorms in the area; wind shear; and busy simultaneous approaches. Not long before our runway assignment had changed.  In review of the event; here is my best recollection.  We were assigned the LAWGR1 arrival and were inside GRUBB being vectored for RWY 16L.  We were about 200-210 KIAS and about 9500 ft MSL. We both saw something white in color glint in the sunlight about our 1-2 o'clock. My copilot later told me he thought he saw it bank sharply to one direction and then to another; uncharacteristic of full sized aircraft. He told me it was not likely a model aircraft and definitely seemed like a multi-rotor type drone. We both saw it and the event started and ended within 5 seconds. Had evasive maneuvers been required; little time was available to affect actual change. We were unable to identify model; number of rotors; size or weight.  By the rate of speed it passed our aircraft; I'd estimate it was within 1/2mi.  My SIC advised ATC. Our original broadcast was blocked. Immediately subsequent we were given a heading to intercept the localizer and in his response; he advised of the drone encounter with pertinent information. Upon landing we were advised by Ground to copy a phone number to contact the TRACON. After securing the aircraft I contacted the TRACON; on the number supplied; spoke with the supervisor; answered his questions; and left my name and number per his request.  As an avid model aircraft flyer; I fully support our right to flight UAS in a safe and responsible way.  Flying UAS at 4000 ft AGL in a busy arrival corridor in Class B airspace is not ok.
Light Transport Captain reported while on initial approach in class B airspace; a UAV within ½ mile at 4000 feet.