Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Air Traffic Control Time Certified In Pos 1 (mon) 9; Air Traffic Control Time Certified In Pos 1 (yrs) 3
Communication Breakdown; Situational Awareness
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Procedure; Human Factors; Environment - Non Weather Related
The Controller working Local 1 before me had issued the initial control instruction to an IFR small jet; inbound on a visual approach from the east. He issued a left base Runway 12R; maintain at or above 035 until turning final. The pilot read the restriction back. There was a single engine aircraft inbound from the northwest on a straight in for Runway 12L. Also issued by the Controller before me. I took the position; and in the briefing the Controller had stated the restriction to small jet. When I assumed the position I issued traffic to the jet on single engine and told him to reduce speed to follow additional traffic on a half mile final for his runway and cleared him to land. The pilot had read back the clearance to land and to reduce his speed. He started descending below the restriction before I cleared him to land. I went to the single engine and told him traffic will be passing off his right for the other runway. The single engine said that aircraft flew 150 feet below him. I thought the jet had said he had the single engine in sight but he didn't. I should have listened more carefully on what the jet pilot said and not what I wanted him to hear. The pilot descended below his restriction before the clearance was issued. That should have been complied with.
A VGT Controller issued mutual traffic to an IFR jet inbound and a single engine in the landing pattern but the jet missed his traffic by 150 feet after he descended for landing but did not have his traffic insight.