Boi TRACON controller reports of two aircraft that were in conflict although both were VFR.

Attributes
ACN	1201562
Time
Date	201409
Local Time Of Day	1801-2400
Place
Locale Reference	BOI.Airport
State Reference	ID
Environment
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft Low Wing 2 Eng Retractable Gear
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	VFR
Aircraft 2
Make Model Name	Small Aircraft High Wing 1 Eng Fixed Gear
Flight Phase	Cruise
Flight Plan	VFR
Person 1
Function	Approach Instructor
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 17
Events
Anomaly	Conflict NMAC Deviation - Procedural Clearance

Narrative:

I was instructing on ars/arn combined. Aircraft X departed and requested vectors for ILS (VFR). Developmental assigned heading; 5000; and maintain VFR to aircraft X. Aircraft Y departed on a similar route as aircraft X. Prior to communication change to our frequency; developmental called local control and requested them to assign aircraft Y 4500ft. When aircraft Y did report on frequency he reported 'at 4500.' developmental issued traffic to both aircraft. Aircraft Y reported aircraft X in sight. Aircraft X was still looking for aircraft Y. Shortly after aircraft X was issued a turn for the ILS; he reported a near midair collision with aircraft Y. After reviewing the tapes;local control issued 'at or above 4500' to aircraft Y. Aircraft X altitude did indicate as low as 4800 after targets merged.reissuing 4500 to aircraft Y seems a bit redundant but possibly could have changed the outcome. Reissuing traffic to aircraft X because he didn't have him in sight might have changed the outcome. Reissuing 5000 to aircraft X after seeing his altitude change might have changed the outcome.

Original NASA ASRS Text

Title: BOI TRACON Controller reports of two aircraft that were in conflict although both were VFR.

Narrative: I was instructing on ARS/ARN combined. Aircraft X departed and requested vectors for ILS (VFR). Developmental assigned heading; 5000; and maintain VFR to Aircraft X. Aircraft Y departed on a similar route as Aircraft X. Prior to communication change to our frequency; Developmental called local control and requested them to assign Aircraft Y 4500ft. When Aircraft Y did report on frequency he reported 'at 4500.' Developmental issued traffic to both aircraft. Aircraft Y reported Aircraft X in sight. Aircraft X was still looking for Aircraft Y. Shortly after Aircraft X was issued a turn for the ILS; he reported a NMAC with Aircraft Y. After reviewing the tapes;local control issued 'at or above 4500' to Aircraft Y. Aircraft X altitude did indicate as low as 4800 after targets merged.Reissuing 4500 to Aircraft Y seems a bit redundant but possibly could have changed the outcome. Reissuing traffic to Aircraft X because he didn't have him in sight might have changed the outcome. Reissuing 5000 to Aircraft X after seeing his altitude change might have changed the outcome.

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.