Narrative:

While working ground control (ground control) I taxied aircraft X to rwy 27R at romeo from the FBO via romeo. I also taxied aircraft Y from the southwest ramp to rwy 27R at romeo via kilo and bravo. At some point during the process I noticed that aircraft X was stopped at the appropriate runway intersection and talking to local Control1 (local control) while I was working a routing/call sign issue for another aircraft. LC2 mentioned that he thought somebody was taking off on the taxiway and I then witnessed aircraft X doing as such; rapidly accelerating westbound on the taxiway towards my now eastbound aircraft Y. My pilot experience told me that aircraft X was very near lifting off of the taxiway so I told aircraft Y to hold position and/or stop (as opposed to turning off into the grass; etc) and he eventually did so before reaching the intersection of bravo and lima. Aircraft X overflew aircraft Y on the taxiway at least at tower height; probably better; it's difficult to recall the specific altitude. I then informed aircraft Y to continue taxiing and gave him the tower's number to call later for their statement.LC1 was distracted with something; with what I'm not sure; but he wasn't watching his airplane. I can only recommend some form of asde that includes a warning for something like this. I'm not even certain asde can do such a thing but I think it would increase awareness to those of us who remain vigilant at all times when performing pertinent duties.

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Original NASA ASRS Text

Title: SFB Ground Controller observes an aircraft that was supposed to be on Local's frequency takeoff from a taxiway with traffic on the taxiway.

Narrative: While working Ground Control (GC) I taxied Aircraft X to Rwy 27R at Romeo from the FBO via Romeo. I also taxied Aircraft Y from the SW Ramp to Rwy 27R at Romeo via Kilo and Bravo. At some point during the process I noticed that Aircraft X was stopped at the appropriate runway intersection and talking to Local Control1 (LC) while I was working a routing/call sign issue for another aircraft. LC2 mentioned that he thought somebody was taking off on the taxiway and I then witnessed Aircraft X doing as such; rapidly accelerating westbound on the taxiway towards my now eastbound Aircraft Y. My pilot experience told me that Aircraft X was very near lifting off of the taxiway so I told Aircraft Y to hold position and/or stop (as opposed to turning off into the grass; etc) and he eventually did so before reaching the intersection of Bravo and Lima. Aircraft X overflew Aircraft Y on the taxiway at least at tower height; probably better; it's difficult to recall the specific altitude. I then informed Aircraft Y to continue taxiing and gave him the tower's number to call later for their statement.LC1 was distracted with something; with what I'm not sure; but he wasn't watching his airplane. I can only recommend some form of ASDE that includes a warning for something like this. I'm not even certain ASDE can do such a thing but I think it would increase awareness to those of us who remain vigilant at all times when performing pertinent duties.

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.