Sat approach controller reported having to vector an aircraft off an approach to avoid an unidentifi...

Narrative:

Aircraft X was an IFR arrival from the west and was given direct to the final approach fix for 13R descending to 4000. I observed a target depart 5c1 initially westbound. I called traffic about 5 miles from the unidentified target and turned aircraft X to the left to avoid the target. As soon as I turned them to the left; the target turned more to the north making the situation worse requiring a larger turn to the right for aircraft X. After all was complete the target passed about 2 miles east of aircraft X. The unidentified aircraft went on to continue their climb up the localizer to 13R further requiring traffic calls for a B737.5c1 is an airport located on a 15 mile final to sat 13R. 13R is the preferred arrival runway and is the most commonly used configuration. There are daily traffic alerts and safety events with aircraft landing sat and aircraft departing and arriving 5c1. There is a broad range of aircraft at 5c1 from high performance jets to gliders making this complicated and even dangerous at times. It is common practice for these aircraft to depart and arrive and affect the flow of traffic into sat. I believe an airspace change that would put a ceiling on how high unidentified non-participating aircraft can climb until they are either talking with ATC or at least clear of the downwinds and final approach course of sat is necessary to prevent these safety issues.

Original NASA ASRS Text

Title: SAT Approach Controller reported having to vector an aircraft off an approach to avoid an unidentified VFR target departing from an adjacent airport underneath the final approach course.

Narrative: Aircraft X was an IFR arrival from the west and was given direct to the final approach fix for 13R descending to 4000. I observed a target depart 5C1 initially westbound. I called traffic about 5 miles from the unidentified target and turned Aircraft X to the left to avoid the target. As soon as I turned them to the left; the target turned more to the north making the situation worse requiring a larger turn to the right for Aircraft X. After all was complete the target passed about 2 miles east of Aircraft X. The unidentified aircraft went on to continue their climb up the localizer to 13R further requiring traffic calls for a B737.5C1 is an airport located on a 15 mile final to SAT 13R. 13R is the preferred arrival runway and is the most commonly used configuration. There are daily traffic alerts and safety events with aircraft landing SAT and aircraft departing and arriving 5C1. There is a broad range of aircraft at 5C1 from high performance jets to gliders making this complicated and even dangerous at times. It is common practice for these aircraft to depart and arrive and affect the flow of traffic into SAT. I believe an airspace change that would put a ceiling on how high unidentified non-participating aircraft can climb until they are either talking with ATC or at least clear of the downwinds and final approach course of SAT is necessary to prevent these safety issues.

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.

Attributes
ACN	1543187
Time
Date	201805
Local Time Of Day	1201-1800
Place
Locale Reference	SAT.TRACON
State Reference	TX
Environment
Light	Daylight
Aircraft 1
Make Model Name	Merlin III
Flight Phase	Initial Approach
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 6
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict

Sat approach controller reported having to vector an aircraft off an approach to avoid an unidentified VFR target departing from an adjacent airport underneath the final approach course.