Light Transport; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2
Confusion; Distraction; Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Human Factors; Procedure
Aircraft X called for his clearance to ZZZ airport.  His clearance was not available and I informed the pilot that I did not have his clearance. After about 3 minutes the pilot called again; and as I was trying to verify if the flight plan was in the system; the clearance popped up and I issued the clearance to the pilot. I do not remember seeing the FRC (Full Route Clearance) remark for a full route clearance on the strip I used to give the clearance to the pilot. Within a few minutes after issuing the clearance; I noticed the strip was removed from the system; I immediately reached out to the pilot informing him that his clearance was removed from the system and that I was going to try to find out what had happened. I called ZSU flight data to find out what the problem was and the controller (whose initials I do not remember) told me that he had removed the flight plan because he had two. I told him I had only one in my system and he said that he would send me the other one; and not to worry about it. I received the second strip and I did not look carefully to notice that there was an FRC remark on the strip. I then inform the pilot that the clearance remained the same and that his new squawk code was XXYY. Just short of departing the local controller informed me that the strip still had an FRC remark on it; which without thinking; I removed without questioning or informing the pilot that he had a full route clearance. When I got home my supervisor called me and asked if I had forgotten to issue the full route clearance to which I said no and informed me that the aircraft was on a closed route (I believe it was L455; which apparently was closed for weather). I do not know the outcome of the aircraft.Regardless of how quick things might be done; and how incomplete a coordination is made between controllers; we should always stick to the basics and read the entire strip looking for changes prior to telling a pilot that his read back was correct; in order to assure the safety of the pilots and the passengers in the NAS. A flag should have raised in my head after noticing that there were two strips; which is usually an indication that something changed and that a full route clearance (FRC) shall be issued.
An SJU Controller failed to issue a full route clearance after missing the note in the remarks of the flight plan. Aircraft became airborne on a closed airway.