A C172 just exiting class B airspace in cruise flight and a climbing B737 have a close encounter.

Attributes
ACN	866520
Time
Date	200912
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	None
Aircraft 2
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 37 Flight Crew Total 2550 Flight Crew Type 2480
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict
Miss Distance	Horizontal 2000 Vertical 500

Narrative:

Flying VFR at 3500 ft. MSL. I was cleared into class B airspace; then exited the lateral boundary of the class B to the north. Receiving radar advisories from approach and in radio and radar contact. A B-737 was being vectored for a climb coming from the southeast; through 3500 feet (final altitude on the jet is unknown). I heard the pilot report he was responding to a TCAS resolution advisory (RA) and leveling off. ATC then advised him to stop the climb. I saw the B-737 in a moderately steep turn below my aircraft; about 500 feet below passing right to left. My aircraft is equipped with ads-B traffic display but this position is out of the current ads-B service area at 3500 feet. The B737; when well clear of my aircraft to the left resumed its climb with ATC clearance. Do not believe there was any threat of conflict or 'near miss'; as standard separation between an IFR and VFR is 500 feet vertically. The B737 was to my right; therefore; in visual conditions they were required to yield the right of way to my aircraft; which was to his left. Being on an IFR flight plan does not relieve the pilot from see and avoid responsibility while in visual conditions. Since ATC had both aircraft in radar contact and was vectoring both aircraft; ATC should have not cleared them to climb through 3500 feet until it was clear of my aircraft. In this author's opinion; ATC vectoring should have been performed to prevent the them from receiving a TCAS RA since both aircraft were in controlled airspace and both under radar vectors.

Original NASA ASRS Text

Title: A C172 just exiting Class B airspace in cruise flight and a climbing B737 have a close encounter.

Narrative: Flying VFR at 3500 ft. MSL. I was cleared into Class B airspace; then exited the lateral boundary of the Class B to the north. Receiving radar advisories from Approach and in radio and radar contact. A B-737 was being vectored for a climb coming from the southeast; through 3500 feet (final altitude on the jet is unknown). I heard the pilot report he was responding to a TCAS resolution advisory (RA) and leveling off. ATC then advised him to stop the climb. I saw the B-737 in a moderately steep turn below my aircraft; about 500 feet below passing right to left. My aircraft is equipped with ADS-B traffic display but this position is out of the current ADS-B service area at 3500 feet. The B737; when well clear of my aircraft to the left resumed its climb with ATC clearance. Do not believe there was any threat of conflict or 'near miss'; as standard separation between an IFR and VFR is 500 feet vertically. The B737 was to my right; therefore; in visual conditions they were required to yield the right of way to my aircraft; which was to his left. Being on an IFR flight plan does not relieve the pilot from see and avoid responsibility while in visual conditions. Since ATC had both aircraft in radar contact and was vectoring both aircraft; ATC should have not cleared them to climb through 3500 feet until it was clear of my aircraft. In this author's opinion; ATC vectoring should have been performed to prevent the them from receiving a TCAS RA since both aircraft were in controlled airspace and both under radar vectors.

Data retrieved from NASA's ASRS site as of April 2012 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.