Commercial Fixed Wing
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 6
Distraction; Time Pressure; Workload
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance
Procedure; Chart Or Publication; Human Factors
Aircraft X on the GIDGT RNAV departure. Aircraft Y on the CHOWW RNAV arrival. Aircraft Y stayed high on the arrival. The outer fix altitude is 19;000 feet. The next restriction is TATUU between 10;500 feet and 9;500 feet. Aircraft X had the restriction of AIRRO at or above 11;500 feet and 250 knots. A vector to Aircraft X southeast was necessary to avoid a loss or possible near midair collision with Aircraft Y. The fixes of TATUU and AIRRO are 8 miles from each other and converge. There is no fix beyond AIRRO for the GIDGT departure. This allows the departure to increase speed and climb slower leaving 11;500 feet. This source converges with the CHOWW arrival at 19;000 feet descending. This is very unsafe. Must lower the altitude at CHOWW to at least 17;000 feet. Also; another fix on the GIDGT beyond AIRRO is needed. This fix should be at least 15;000 feet with a speed not to exceed 250 knots.
A L30 TRACON Controller reported issuing vectors to avoid an NMAC between two aircraft flying published RNAV procedures when the arriving aircraft 'stayed high' on the arrival to LAS airport. The reporter states the CHOWW RNAV arrival procedure conflicts with the GIDGT RNAV SID.