Falcon 10/100
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 10
Situational Awareness
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Separated Traffic; Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Became Reoriented
Chart Or Publication; Human Factors; Procedure; ATC Equipment / Nav Facility / Buildings
Aircraft X departed SJC on SJC2 Departure. Approximately one half mile off the departure end I noticed the aircraft in a right turn climbing out of 1400 feet. The aircraft appeared not to be on the correct departure procedure; and was turning inside of the previous departure off of SJC Aircraft Y. I turned Aircraft Y to heading 090; and amended Aircraft X's altitude to maintain 4000. I established vertical and lateral separation between both aircraft and the vectored both aircraft on their proper way.Again an aircraft does not fly a departure procedure correctly off of SJC. Last week I filed two separate reports on two aircraft within 7 minutes of each other that did not fly the procedures correctly. The departure procedures off of SJC have been poorly developed and published. SJC has a long history of aircraft not flying the departure procedures correctly. The SIDs are at times confusing to the pilots; and every departure flies the procedure differently. Again; I recommend that since SJC Tower is responsible for successive departure separation; that they ensure aircraft are in the turn appropriately prior to communication transfer. Because this doesn't happen; SJC Tower keeps launching departures while the departure controller is busy trying to point out; and separate these aircraft that don't fly the departure right.
Our clearance required the SJC2 departure procedure from SJC. Prior to take off; I advised the copilot that we were not receiving the DME from SJC VOR probably due to line of sight issues. I had a GPS DME from a waypoint behind us (MOONY); so I suggested we add 1.8 DME to it in the event we did not get the SJC DME after takeoff. We were then given a takeoff clearance and after takeoff were still not receiving the SJC DME. We started our turn on our previous discussion using the GPS DME. Upon completing the turn; approach advised us we may have a violation due to early turn. He said we got too close to the aircraft that took off before us. I advised him that we were not receiving the SJC DME; so we used the GPS DME. At 59.7 DME from SJC our DME came on. I'm not sure if it was the VOR or our equipment that was down. The departure calls for a 180 degree course change; so I'm not really sure how ATC expected to have separation when the other aircraft is essentially turning back towards us on departure without vertical separation.We also were having a cabin pressurization issue on departure that was distracting; but probably could have thought of advising ATC of the lack of DME from SJC VOR.
NCT Controller and flight crew reported the pilots flew the SID incorrectly into confliction with a previous departure.