B737-300
ATC Issue All Types
General None Reported / Taken
ATC Equipment / Nav Facility / Buildings; Procedure; Human Factors
Was advised by an Area '3' controller at Sector 09 that a data block had disappeared off his scope and he couldn't remember who it was. I pulled up a FALCON recording to see which aircraft disappeared. It was a B737; and the call sign had two entries in HOST. It also showed position 'D20' removing the strip that was active in Sector 09; and inputting a DM message on the 'other' B737. When I asked the Sector 20 Controller about the aircraft; he stated that RDUZ called with a manual hand off and asked him to remove the ticket because the aircraft wouldn't track up. Long story short; [we had] two aircraft with the same call sign in ZDC airspace at the same time. This occurred on a mid-shift so the impact was minimal. I called the B737 Company's Dispatch and they were aware of the problem and explained that the one flight was 7 hours late. He also advised that there were 3 separate legs with that call sign and they changed one; but did not anticipate having to change the third. [There] should already be some kind of software firewall with dispatch to prevent this; maybe a call to the Command Center or the affected Center to warn them of this. Controller techniques: Need to be very cautious when removing a flight plan. A call for a manual hand off should have tipped off the Controller that something was not quite right. Finally; doing a QR or an automated hand off attempt to a 'not in use' sector would have shown that Sector 09 had control of the aircraft.
ZDC Controller described an unsafe condition when an adjacent controller 'removed strip' on traffic that was active in another sector.