Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 4.5
Communication Breakdown; Situational Awareness; Confusion
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Airspace Structure; Human Factors; Procedure
I received an IFR release on Aircraft X; who was departing BUR on the OROSZ 1 SID (right turn heading 210 off Runway 15). After clearing the aircraft for takeoff I shipped the aircraft to SCT. As I did that; I noticed that at the same time my target was acquiring on the scope; a PMD departure was tagging up off VNY Runway 16 (left turn heading 110). The two SIDs conflict with each other and by default SCT will only release one aircraft at a time. However; it was a slow morning and it's not unheard of for SCT to release both at once when they're not busy and manually vector the aircraft off VNY to the west to keep them away from the BUR departure. That is very rare; but I've occasionally seen it and I figured that since it was a very slow morning; that must have been what SCT was doing. It became apparent that they were not doing that; as I saw both aircraft converging and climbing to the same altitude (4;000 feet MSL). I didn't want to reach out to SCT and bother the controller working the Valley Sector while they worked the problem out.At that point; the SCT Valley controller reached out to me on the shout line and told me to turn Aircraft X to a 340 heading now. I replied that I had shipped him off departure end; but I would reach out and try again. I transmitted for Aircraft X to turn right heading 340 immediately. Aircraft X replied to me; as apparently he had never taken the frequency change. He read back the turn to 340; and I issued a traffic alert for Aircraft Y off VNY; who was now at about 2 miles and still converging. I told him to maintain visual separation (even though both aircraft have the same initial altitude of 4;000 feet. I knew separation was lost but I just wanted to make sure they wouldn't hit). Once Aircraft X was established on his heading of 340 and pointed away from Aircraft Y; I re-shipped Aircraft X to SCT. Separation was definitely lost.Don't assume what another controller is doing. As soon as I saw the PMD departure off VNY; I should have called Valley and asked if he wanted me to do something with Aircraft X before shipping Aircraft X.
Burbank Tower Controller reported that an aircraft departed Burbank and became an airborne conflict with a Van Nuys departure on the same routing.