Small aircraft pilot reported taking evasive action due to airborne conflict with jet traffic.

Narrative:

Departed 1h0 to the south and contacted spirit (ksus) tower to transit airspace enroute to ZZZ1. Transition was approved south of the airport and ksus indicated they had positive radar contact of my aircraft. While flying south of ksus at 2;500 MSL and still on frequency; I heard ksus tower say 'aircraft Y are you with me?' about 30 seconds later ksus repeated this inquiry with no response again from aircraft Y. At this point; I looked down at my ipad which was connected to a portable ads-B receiver and noticed reported traffic 11 o'clock high; descending; and heading in the exact opposite direction of my flight path. I began a small turn to the right and held my altitude at 2;500 MSL. I visually located the traffic maybe 1 NM away and descending toward me. I continued my right turn away from the jet and estimate it passed off my left wing within 1;000 feet. Shortly after aircraft Y passed me I heard them say 'aircraft Y is with you spirit tower.' ksus tower then gave them permission to enter the pattern and said nothing to me or aircraft Y about the near miss. I did not say anything to ksus after the incident either. My best guess is that aircraft Y was on the kstl approach frequency and was not handed off quickly enough or did not switch frequencies quickly enough when entering spirit's airspace. I'm not sure why the controller did not try to contact me for evasive action when aircraft Y did not respond.

Original NASA ASRS Text

Title: Small Aircraft pilot reported taking evasive action due to airborne conflict with jet traffic.

Narrative: Departed 1H0 to the south and contacted Spirit (KSUS) Tower to transit airspace enroute to ZZZ1. Transition was approved south of the airport and KSUS indicated they had positive radar contact of my aircraft. While flying south of KSUS at 2;500 MSL and still on frequency; I heard KSUS Tower say 'Aircraft Y are you with me?' About 30 seconds later KSUS repeated this inquiry with no response again from Aircraft Y. At this point; I looked down at my iPad which was connected to a portable ADS-B receiver and noticed reported traffic 11 o'clock high; descending; and heading in the exact opposite direction of my flight path. I began a small turn to the right and held my altitude at 2;500 MSL. I visually located the traffic maybe 1 NM away and descending toward me. I continued my right turn away from the jet and estimate it passed off my left wing within 1;000 feet. Shortly after Aircraft Y passed me I heard them say 'Aircraft Y is with you Spirit Tower.' KSUS Tower then gave them permission to enter the pattern and said nothing to me or Aircraft Y about the near miss. I did not say anything to KSUS after the incident either. My best guess is that Aircraft Y was on the KSTL Approach frequency and was not handed off quickly enough or did not switch frequencies quickly enough when entering Spirit's airspace. I'm not sure why the controller did not try to contact me for evasive action when Aircraft Y did not respond.

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	1583929
Time
Date	201810
Local Time Of Day	0601-1200
Place
Locale Reference	SUS.Tower
State Reference	MO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft Low Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	None
Aircraft 2
Make Model Name	Cessna Citation Undifferentiated or Other Model
Flight Phase	Final Approach
Person 1
Function	Single Pilot
Qualification	Flight Crew Private
Experience	Flight Crew Last 90 Days 20 Flight Crew Total 48 Flight Crew Type 48
Events
Anomaly	Conflict Airborne Conflict
Miss Distance	Horizontal 500 Vertical 500