Narrative:

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 runway 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.

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Original NASA ASRS Text

Title: Light Transport Captain reported while on initial approach in class B airspace; a UAV within ½ mile at 4000 feet.

Narrative: 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.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.