Skyhawk 172/Cutlass 172
Air Traffic Control Fully Certified
Situational Awareness; Communication Breakdown; Confusion
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Ground Event / Encounter Other / Unknown
Air Traffic Control Issued New Clearance
Human Factors; Procedure
I was working Ground Control and Clearance Delivery combined with training in progress on the Local position. FAA Mobile Vehicle ABC called Ground Control and requested to drive near the threshold of Runway XXR. I misunderstood the transmission. I thought he was requesting Runway XXL. I coordinated with Local when able drive Runway XXL from the approach end and hold short of Runway YY. Local had a VFR Cessna inbound to Runway XXL; but local changed them to Runway XXR; so I could use the threshold area for Runway XXL. After getting approval from Local Control; I told Mobile ABC to drive Runway XXL hold short of Runway YY. Mobile ABC responded that he wanted Runway XXR not Runway XXL. I instructed Mobile ABC to hold short of Runway XXR because the Cessna was not inbound to that runway. After these transmissions; Mobile ADC called me requesting to proceed to the Runway 36 glide slope area on the other side of the airfield. I had some confusion with Mobile ABC; and a talked to him more than usual. I immediately responded to Mobile ADC's request; but I said Mobile ABC drive as requested hold short of Runways XXR; XXL; and YY. Mobile ABC and ADC both started moving. Mobile ABC went up to the threshold of XXR but not on the runway; and the Cessna was on final to that runway. Mobile ADC proceeded to the Runway 36 glide slope at the same time. The Cessna was instructed to go around because Mobile ABC was near the threshold of the runway. There was no runway incursion; but the Cessna was sent around just in case. I should be more alert with similar sounding vehicles and what requests are being made. Although I made some mistakes in this situation; having FAA mobile vehicle callsigns not be so similar would help save some confusion. Mobile ADC and ABC sound very alike.
Ground Controller described a go-around event when two vehicles with similar call signs were requesting access to runways. The reporter noted more care should have been exercised by all involved.