Narrative:

I was working the ground control position and the airport was in west traffic runway 21 in use. Local had what appeared to be 3 aircraft doing pattern work on the south side and 1 or 2 in the down wind on the north side. Everything was flowing smooth until the TRACON started feeding us a string of IFR jets inbound to the airport. The spacing of the jet arrivals was starting to make it difficult to mix the slower single prop traffic in the down winds. Local control sequenced a light sport in front of a G4 and it was going to be close due to a huge speed difference. The local controller instructed the G4 to south turn and reduce speed for spacing and the pilot did an amazing job. However; the overtake was just too great. I watched it as long as I felt I could and finally said to local; 'this is not going to work'. With the light sport just over the fence and the G4 at what appeared to be 1/4 mile final the local controller told the light sport to go-around. The pilot of light sport stayed over the runway at approximately 30 AGL. At this point the controller in charge; as well as me; were telling the local controller to send the G4 around. Local told the light sport to go-around again before realizing that that will not work either and then sends the G4 around. The G4 passed overtop of the light sport by what appeared to be less than 100 ft mid field with both aircraft still over the runway. Both aircraft later landed without incident.I firmly believe that the local controllers' lack of knowledge when it comes to aircraft operation was directly linked to this incident. Further familiarization with aircraft performance and pilot work load is a must as well as learning to recognize when a loss so acceptable separation is about to occur and take the right action to fix it as soon as possible.

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Original NASA ASRS Text

Title: Tower Controller described a pilot filed NMAC during a confused go-around instruction; the reporter citing the operating Controllers lack of experience as a major factor in this event.

Narrative: I was working the Ground Control position and the airport was in west traffic Runway 21 in use. Local had what appeared to be 3 aircraft doing pattern work on the south side and 1 or 2 in the down wind on the north side. Everything was flowing smooth until the TRACON started feeding us a string of IFR jets inbound to the airport. The spacing of the jet arrivals was starting to make it difficult to mix the slower single prop traffic in the down winds. Local Control sequenced a light sport in front of a G4 and it was going to be close due to a huge speed difference. The Local Controller instructed the G4 to S turn and reduce speed for spacing and the pilot did an amazing job. However; the overtake was just too great. I watched it as long as I felt I could and finally said to Local; 'this is not going to work'. With the light sport just over the fence and the G4 at what appeared to be 1/4 mile final the Local Controller told the light sport to go-around. The pilot of light sport stayed over the runway at approximately 30 AGL. At this point the CIC; as well as me; were telling the local Controller to send the G4 around. Local told the light sport to go-around again before realizing that that will not work either and then sends the G4 around. The G4 passed overtop of the light sport by what appeared to be less than 100 FT mid field with both aircraft still over the runway. Both aircraft later landed without incident.I firmly believe that the Local Controllers' lack of knowledge when it comes to aircraft operation was directly linked to this incident. Further familiarization with aircraft performance and pilot work load is a must as well as learning to recognize when a loss so acceptable separation is about to occur and take the right action to fix it as soon as possible.

Data retrieved from NASA's ASRS site as of July 2013 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.