Air carrier captain reported a drone sighting while established on arrival to san.

Attributes
ACN	1595625
Time
Date	201811
Local Time Of Day	0601-1200
Place
Locale Reference	SCT.TRACON
State Reference	CA
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	STAR LUCKI ONE
Flight Plan	IFR
Aircraft 2
Make Model Name	UAV - Unpiloted Aerial Vehicle
Operating Under FAR Part	Part 91
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Events
Anomaly	Conflict Airborne Conflict Deviation - Procedural Published Material / Policy Deviation - Procedural FAR

Narrative:

On approach to san we saw what appeared to be a drone or unidentified aircraft crossing our flight path. We called it and were asked what altitude. We replied possibly 5000 feet or 6000 feet MSL. We were issued to fly localizer 27 or RNAV 27 after lucki arrival and keep the speed up. We closed the loop and remarked about the [weather] south of the border and were both curious what a large drone would have been doing. About 5000 feet on arrival; we were questioned as to our track and asked if we had the field in sight. We replied yes and after landing were asked to contact ATC.

Original NASA ASRS Text

Title: Air Carrier Captain reported a drone sighting while established on arrival to SAN.

Narrative: On approach to SAN we saw what appeared to be a drone or unidentified aircraft crossing our flight path. We called it and were asked what altitude. We replied possibly 5000 feet or 6000 feet MSL. We were issued to fly LOC 27 or RNAV 27 after LUCKI Arrival and keep the speed up. We closed the loop and remarked about the [weather] south of the border and were both curious what a large drone would have been doing. About 5000 feet on arrival; we were questioned as to our track and asked if we had the field in sight. We replied yes and after landing were asked to contact ATC.

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.