A319
Air Traffic Control Fully Certified
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance
Human Factors; Procedure
This was a busy combined position. I was working both the Feeder and Final because we were short staffed. In addition; we had a flight check in the area and sequence was trying to coordinate with me on his handling. An E135 had to be taken out of the final sequence because another aircraft had navigation problems on the approach causing the arrival line to 'bunch up.' I vectored the E135 westbound at 5;000 FT because there was an aircraft on the downwind at 4;000 FT. The next aircraft coming in; an A319 was also descended to 5;000 FT because in my judgment if they had stayed on the arrival the two aircraft would pass no factor. Unfortunately; the A319 'led' the turn on the STAR causing them to pass too closely to the E135. Both aircraft responded to an RA. The unusual situation with flight check and the required coordination was certainly a factor in distracting me. Also; the aircraft that had a navigation problem caused a lot of work all at once. If the position was separated the traffic volume and complexity would have been halved. Additionally; the A319 leading the turn is dangerous and the pilots of those aircraft should be reminded that it is bad practice in such a confined airspace like New York.
N90 Controller described a loss of separation event complicated by a flight check aircraft.