Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 3.5
Situational Awareness; Confusion; Human-Machine Interface
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Provided Assistance
ATC Equipment / Nav Facility / Buildings; Weather; Procedure
I was working a sector. I was talking to two aircraft at the time. This aircraft was going to ZZZ airport. These aircraft get descended to 11000 feet and handed off to TRACON. Around the middle of my sector; after TRACON took radar handoff; all of my information disappeared. The entire data block; flight plan etc. The aircraft became a Mode C intruder on the previous assigned code. Upon my further investigation I found the exact same call sign; a departure leaving ZZZ1 airport. I asked the pilot about why he thought company would do that to which he told me that his flight was delayed due to maintenance. I would assume that the pilot called this in to company because about 5 minutes later the call sign of the other aircraft; the ZZZ1 departure was changed by the company. At this point it made no difference because my flight plan information was already gone. TRACON still had their information. Further investigation by my supervisor led to the discovery that TRACON; unable to depart the flight plan in the system (obviously because one was active) removed strip with logic override; which led to my information disappearance. Had this happened with the sector busy it could've been disastrous. This happens to us all the time in the summer during SWAP (Severe Weather Avoidance Program). Flights get delayed; same call signs are still inbound to the metro area and the outbound flight gets airborne. We always change the call sign. I really don't understand why the airlines use a certain call sign multiple times per day. There must be enough call sign numbers to have a different number for every flight every day.  In SWAP this adds complexity and an extreme amount of workload to an already busy sector. Being able to remove strips would make it much easier; but someone somewhere would lose all their information. I would recommend that the companies use a call sign for one flight only.
ZNY ARTCC Controller reported a TRACON Controller entered a remove strip message on a flight plan. The Controller had to override the flight plan control to enter the message. An aircraft with the same call sign was active in ARTCC airspace. The data tag on the ARTCC Controllers radar disappeared from the display.