Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 4
Troubleshooting; Situational Awareness; Distraction; Communication Breakdown; Confusion
Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Separated Traffic
Procedure; Human Factors; Aircraft
Aircraft X and Aircraft Y departed via RBV.J230.  I climbed Aircraft X to FL280.  Read back was unclear; and the frequency was blocked.  I believed that Aircraft Y was making his initial check-in; but see he had already started to climb; so again I climb Aircraft X to FL280.  I continue my scan and see that Aircraft Z departing LGA to CYYZ via Newel was climbing at FL185 and was flashing with a Lendy arrival from Area C sector 36. I call N90 and see if they were climbing this aircraft.  They informed me that no and that he had been switched to my frequency.  I then descend Aircraft Z to 170 expedite for traffic.  I call sector 36; and advise him that I am descending my aircraft and that he must have taken another aircrafts instructions.  The sector 36 controller turned his aircraft to the left to avoid Aircraft Z and stopped his descent.  I did not recall the Aircraft Z checking on; but there must have been some frequency congestion and blocking and the wrong aircraft took the wrong instructions. First; there were many distractions for a good time before this incident.  There were many deviations by RBV and the N90 controller had to continuously call to coordinate deviations.  Also; similar sounding call signs were a factor.  Frequency congestion for deviations and also landline congestions for the extraneous coordination; it is sometimes difficult to keep the aircraft from blocking the check in.  If there are that many deviations; an in-trail restriction should go into place.  Companies should refrain from using call signs so similar because it causes unnecessary confusion.
ZNY Controller reports of similar sounding call signs causing confusion and pilots taking the others clearances.