EMB ERJ 190/195 ER/LR
Air Traffic Control Fully Certified
Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude
Flight Crew Took Evasive Action
Procedure; Aircraft; Human Factors
An E190 was descending to 9;000 FT from 10;000 FT. A VFR overflight BE36 reported level at 8;500 FT; altitude varied by 100-200 FT at times. Both aircraft were issued traffic as targets were likely to merge. At approximately 2 miles lateral separation the BE36 reported the E190 in sight. The E190 was immediately informed that traffic had them in sight; and response was 'We are responding to an RA'. The aircraft did not say they were climbing; but I believe they stopped the descent and climbed 100 FT-200 FT. At the time the BE36; even though he had reported being level at 8;500 FT; altitude indicated 8;600 FT. I don't believe they were at the time; but aircraft may have been inside Bravo airspace. The BE36 was not instructed to maintain visual separation from the E190. The supervisor was not immediately available; but was notified about 2-3 minutes after the incident. I reported to the supervisor that the E190 had responded to an RA; but that I didn't think there was an evasive maneuver; just decreased rate of descent. After thinking about the situation more; I believe the E190 may have climbed 100-200 FT. I should have stopped the E190 at a higher altitude since the BE36 was indicating 100 FT-200 FT difference; anticipating that there could possibly be a TCAS event. I think more frequent training and actually hearing from pilots how TCAS works could help controllers be more aware of such a situation. Also more training; on how if a pilot reports a specific altitude and has the right altimeter setting and altitude differs by 100 FT how does this have an effect on TCAS.
L30 Controller described a TCAS RA event between a descending air carrier and a VFR aircraft in level flight. The VFR aircraft observed the air carrier but was not instructed to maintain visual separation.