Regional Jet 900 (CRJ900)
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Situational Awareness
Conflict NMAC
General Police / Security Involved
Procedure; Aircraft; Airspace Structure
While conducting [line check] with a return to work First Officer; we had a close encounter with a drone.  We were on the down-wind approximately 5 NM east of DTW being vectored for a visual approach to [Runway] 21L in VMC.  We were level at 8;000 feet MSL; speed 250 KIAS; when the First Officer observed a drone very quickly go past the right side (his side) of the aircraft at very close range (within a hundred or so feet) and slightly below our altitude.  It appeared to be approximately 2 feet in diameter; roughly square shaped; and was green and white in color.  We advised ATC and gave basic details of the location; altitude and description.  After arrival; and after leaving the aircraft and gate area; I received a call from Detroit Airport Operations and returned to the gate at their request.
Regional jet Captain reported encountering a drone while on downwind for landing at Detroit airport.