B737 pilot reported sighting a drone while on the veeck arrival into O'hare airport at 11;000 feet.

Attributes
ACN	1618398
Time
Date	201902
Local Time Of Day	1201-1800
Place
Locale Reference	ORD.Airport
State Reference	IL
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR VEECK
Flight Plan	IFR
Aircraft 2
Make Model Name	UAV - Unpiloted Aerial Vehicle
Operating Under FAR Part	Other 107
Flight Phase	Other unknown
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 209 Flight Crew Total 4780 Flight Crew Type 3906
Events
Anomaly	Conflict NMAC Inflight Event / Encounter Object

Narrative:

We were arriving into ord on the veeck arrival. We were level at 11;000 ft. About 8.5nm south of cluso intersection. As we were receiving instructions from ATC; I was heads up and saw a black object on the horizon approaching. At first; I thought it was a mylar balloon; but as it approached; I could easily see that it was irregular in shape. As it came closer; it was clearly an unmanned aircraft. It was all black; and multi-rotor. It passed our left wing at our altitude. It was difficult to determine how far away it was; but couldn't have been more than 1;000 ft. Away due to the details I could see. It was likely closer than that. The captain was heads down at the time; and on the radio; and didn't see the [object]. She reported it to ATC. We didn't call it a near midair collision at that moment; but probably should have. We were busy with ATC instructions for heading; altitude; and airspeed changes. The rest of the flight continued uneventfully.

Original NASA ASRS Text

Title: B737 pilot reported sighting a drone while on the VEECK arrival into O'Hare airport at 11;000 feet.

Narrative: We were arriving into ORD on the VEECK arrival. We were level at 11;000 ft. about 8.5nm south of CLUSO intersection. As we were receiving instructions from ATC; I was heads up and saw a black object on the horizon approaching. At first; I thought it was a mylar balloon; but as it approached; I could easily see that it was irregular in shape. As it came closer; it was clearly an unmanned aircraft. It was all black; and multi-rotor. It passed our left wing at our altitude. It was difficult to determine how far away it was; but couldn't have been more than 1;000 ft. away due to the details I could see. It was likely closer than that. The Captain was heads down at the time; and on the radio; and didn't see the [object]. She reported it to ATC. We didn't call it a NMAC at that moment; but probably should have. We were busy with ATC instructions for heading; altitude; and airspeed changes. The rest of the flight continued uneventfully.

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.