Narrative:

Aircraft X called for taxi and I gave him taxi instructions to the departure runway. I spoke with the aircraft multiple times and did not hear the callsign any differently; nor did the pilot try to correct me from my knowledge. As the aircraft was cleared for takeoff by the local controller; the pilot must have made his callsign out more clearly to him than it had been to me; because the local controller turned to me and advised that it was actually aircraft Y [a company callsign with a one number difference] on departure roll. Very similar sounding callsigns; very similar aircraft types. We should advise the company that there is no reason to have such similar callsigns with proposed departure times only 10 minutes apart.

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Original NASA ASRS Text

Title: JFK Controller reported two aircraft with nearly identical call signs caused the wrong flight to be coordinated.

Narrative: Aircraft X called for taxi and I gave him taxi instructions to the departure runway. I spoke with the aircraft multiple times and did not hear the callsign any differently; nor did the pilot try to correct me from my knowledge. As the aircraft was cleared for takeoff by the Local Controller; the pilot must have made his callsign out more clearly to him than it had been to me; because the Local Controller turned to me and advised that it was actually Aircraft Y [a company callsign with a one number difference] on departure roll. Very similar sounding callsigns; very similar aircraft types. We should advise the company that there is no reason to have such similar callsigns with proposed departure times only 10 minutes apart.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.