A GLF5 and a C-172 experienced an near midair collision while in a mixed IFR/VFR situation.

Attributes
ACN	897857
Time
Date	201007
Local Time Of Day	1201-1800
Place
Locale Reference	ARR.Airport
State Reference	IL
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Gulfstream V / G500 / G550
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Skyhawk 172/Cutlass 172
Flight Phase	Climb
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 60 Flight Crew Total 15400 Flight Crew Type 340
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 0 Vertical 400

Narrative:

While on vectors for a visual approach into arrival; TRACON advised of traffic 11 o'clock and 500' below us. This target started climbing before it could be visually acquired. Simultaneous TA; RA ;'monitor vertical speed'; 'climb' TCAS alerts were issued and followed by the pilot flying. TRACON was promptly alerted using standard phraseology. Total vertical deviation was +400' before conflict was resolved. Target aircraft was acquired visually passing 400' below by pilot not flying.

Original NASA ASRS Text

Title: A GLF5 and a C-172 experienced an NMAC while in a mixed IFR/VFR situation.

Narrative: While on vectors for a visual approach into ARR; TRACON advised of traffic 11 o'clock and 500' below us. This target started climbing before it could be visually acquired. Simultaneous TA; RA ;'monitor vertical speed'; 'climb' TCAS alerts were issued and followed by the pilot flying. TRACON was promptly alerted using standard phraseology. Total vertical deviation was +400' before conflict was resolved. Target aircraft was acquired visually passing 400' below by pilot not flying.

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.