Regional Jet 700 ER/LR (CRJ700)
Air Traffic Control Fully Certified
Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance
Procedure; Human Factors
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.
M98 Controller described a technical loss of separation event when traffic was issued an approach clearance as parallel traffic drifted off the localizer.