M98 controller described a technical loss of separation event when traffic was issued an approach cl...

Attributes
ACN	988620
Time
Date	201201
Local Time Of Day	1201-1800
Place
Locale Reference	MSP.Airport
State Reference	MN
Aircraft 1
Make Model Name	Regional Jet 700 ER/LR (CRJ700)
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	EMB ERJ 170/175 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Person 1
Function	Approach Departure
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

Narrative:

A CRJ7 was on a vector to join localizer with approach clearance to runway 12L at 4;000 ft MSL. An E170 was cleared for approach at 5;000 to runway 12R. One and one half miles of separation is required when both aircraft are established on localizers. The E170 was given the approach clearance when I noticed the CRJ7 was approximately 1/2 mile off localizer at 4;000 and less than three miles from the E170. I attempted to stop the E170 at 5;000; but the aircraft had already departed that altitude. With hold approach clearance until both aircraft are established on localizer.

Original NASA ASRS Text

Title: M98 Controller described a technical loss of separation event when traffic was issued an approach clearance as parallel traffic drifted off the localizer.

Narrative: A CRJ7 was on a vector to join localizer with approach clearance to Runway 12L at 4;000 FT MSL. An E170 was cleared for approach at 5;000 to Runway 12R. One and one half miles of separation is required when both aircraft are established on localizers. The E170 was given the approach clearance when I noticed the CRJ7 was approximately 1/2 mile off localizer at 4;000 and less than three miles from the E170. I attempted to stop the E170 at 5;000; but the aircraft had already departed that altitude. With hold approach clearance until both aircraft are established on localizer.

Data retrieved from NASA's ASRS site as of July 2013 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.

M98 controller described a technical loss of separation event when traffic was issued an approach clearance as parallel traffic drifted off the localizer.