Narrative:

Aircraft Z was handed off from jackson approach at 5000 with an intermittent transponder. Picayune low (H27) called to block 4000 and below for a westbound departure; aircraft X to cll. I approved the block. I coordinated aircraft Z as a primary target at 5000 direct jka. H27 said they could not see the aircraft and approved nonradar at 5000. Shortly after that I lost radar on aircraft Z also. H27 called to apreq (approval request) aircraft X climbing to FL230 when he was clear of aircraft Z; and I approved it. At the same time; H27 apreqed another laurel departure; aircraft Y; climbing to 3000 northeast bound to bna. I approved this as well; and switched aircraft Z to H27. Aircraft X came up on my frequency level at 4000; looking for higher. When he was clear of aircraft Z's nonradar route; I climbed him to FL230; then called H27 to make sure they were still watching him since he was going back into their airspace. They said that they thought aircraft Z was on the boundary; but weren't completely sure. I handed aircraft X off to H65; the high sector; and switched him. H27 calls to apreq aircraft Y climbing to FL230. I asked him if aircraft Z was clear of my airspace; and he said 'I think I see him south of your airspace.' I questioned it; and he said they would provide separation between aircraft Y and aircraft Z. I approved aircraft Y climbing to FL230.a training team came in to train; so I gave a briefing. I didn't remember aircraft Y coming up; so I tried him and he answered. I assigned him a 045 heading to miss military airspace north of mei. The response was '045 heading; aircraft X'; I finish giving the briefing; and get up. As I'm getting ready to leave; aircraft X turns northbound back into our airspace; and FL340 appears in his data block. I walk over to sector 45; the high sector; and tell him about aircraft X climbing and turning. The trainee that relieved me tried aircraft Y again and he doesn't respond; and has not turned to a 045 heading. Houston called to coordinate with R45 that aircraft X would continue a right turn to cll; then the plane turned left. R65 finally gets aircraft Y and turns him around the MOA.sector 45 was fairly busy and had several airplanes at various altitudes in the area aircraft X turned towards. I can only think that the pilot of aircraft X didn't switch frequencies when I told him to contact H65; then took the turn for aircraft Y; who wasn't on frequency yet. I had a feeling aircraft Y wasn't on yet; and that should have been my clue to be extra vigilant; but when he responded; I thought I must have just forgotten he checked on in the confusion of the nonradar; successive lul departures; MOA activity; and position relief briefing. I probably should have waited to give the briefing until I had everything nailed down; but it didn't seem bad enough to delay the briefing at the time.[company] has several aircraft and they tend to time their flights so that they all leave at the same time and arrive at the same time. All their call signs take the form abcdef or abgdef; and when they all come back at once; it can lead to confusion for both the controllers and the pilots (do the pilots rotate through the planes? If they're on [one call sign] for a few days and then switch; it would be easy to get confused on which call sign you should be responding to).I got distracted with the nonradar separation of departures at laurel. Aircraft Z was flying nearly directly over lul; and held down departures that normally would have climbed quickly and dispersed. Instead; they got held down and callsign confusion occurred. Both pilots and controllers need to be careful that they're using the correct callsigns.I don't know what houston's part in this was; we didn't really hear anything from them until they coordinated with R45. They put FL340 in the data block after aircraft X had turned back to the north; indicating they were climbing him; but hadn't coordinated anything with R45. That left some scrambling to figure out if they were actually climbing him into 45's airspace or not. It looked at that time as if they were talking to him; it didn't occur to me that they weren't until the trainee said he didn't have aircraft Y. Houston does this a lot; they'll change the altitude that is in the data block after accepting a handoff but before we actually switch the plane; which leads to confusion; did I already switch him; are they doing something with him? We might have diagnosed that aircraft Y wasn't actually on frequency quicker if houston hadn't changed the altitude.

Related reports:

Google
 

Original NASA ASRS Text

Title: ZME Controller reported two aircraft had similar call signs. One aircraft may have taken the other's clearance.

Narrative: Aircraft Z was handed off from Jackson Approach at 5000 with an intermittent transponder. Picayune Low (H27) called to block 4000 and below for a westbound departure; Aircraft X to CLL. I approved the block. I coordinated Aircraft Z as a primary target at 5000 direct JKA. H27 said they could not see the aircraft and approved nonradar at 5000. Shortly after that I lost radar on Aircraft Z also. H27 called to apreq (Approval Request) Aircraft X climbing to FL230 when he was clear of Aircraft Z; and I approved it. At the same time; H27 apreqed another Laurel departure; Aircraft Y; climbing to 3000 northeast bound to BNA. I approved this as well; and switched Aircraft Z to H27. Aircraft X came up on my frequency level at 4000; looking for higher. When he was clear of Aircraft Z's nonradar route; I climbed him to FL230; then called H27 to make sure they were still watching him since he was going back into their airspace. They said that they thought Aircraft Z was on the boundary; but weren't completely sure. I handed Aircraft X off to H65; the high sector; and switched him. H27 calls to apreq Aircraft Y climbing to FL230. I asked him if Aircraft Z was clear of my airspace; and he said 'I think I see him south of your airspace.' I questioned it; and he said they would provide separation between Aircraft Y and Aircraft Z. I approved Aircraft Y climbing to FL230.A training team came in to train; so I gave a briefing. I didn't remember Aircraft Y coming up; so I tried him and he answered. I assigned him a 045 heading to miss military airspace north of MEI. The response was '045 heading; Aircraft X'; I finish giving the briefing; and get up. As I'm getting ready to leave; Aircraft X turns northbound back into our airspace; and FL340 appears in his data block. I walk over to sector 45; the high sector; and tell him about Aircraft X climbing and turning. The trainee that relieved me tried Aircraft Y again and he doesn't respond; and has not turned to a 045 heading. Houston called to coordinate with R45 that Aircraft X would continue a right turn to CLL; then the plane turned left. R65 finally gets Aircraft Y and turns him around the MOA.Sector 45 was fairly busy and had several airplanes at various altitudes in the area Aircraft X turned towards. I can only think that the pilot of Aircraft X didn't switch frequencies when I told him to contact H65; then took the turn for Aircraft Y; who wasn't on frequency yet. I had a feeling Aircraft Y wasn't on yet; and that should have been my clue to be extra vigilant; but when he responded; I thought I must have just forgotten he checked on in the confusion of the nonradar; successive LUL departures; MOA activity; and position relief briefing. I probably should have waited to give the briefing until I had everything nailed down; but it didn't seem bad enough to delay the briefing at the time.[Company] has several aircraft and they tend to time their flights so that they all leave at the same time and arrive at the same time. All their call signs take the form ABCDEF or ABGDEF; and when they all come back at once; it can lead to confusion for both the controllers and the pilots (do the pilots rotate through the planes? If they're on [one call sign] for a few days and then switch; it would be easy to get confused on which call sign you should be responding to).I got distracted with the nonradar separation of departures at Laurel. Aircraft Z was flying nearly directly over LUL; and held down departures that normally would have climbed quickly and dispersed. Instead; they got held down and callsign confusion occurred. Both pilots and controllers need to be careful that they're using the correct callsigns.I don't know what Houston's part in this was; we didn't really hear anything from them until they coordinated with R45. They put FL340 in the data block after Aircraft X had turned back to the north; indicating they were climbing him; but hadn't coordinated anything with R45. That left some scrambling to figure out if they were actually climbing him into 45's airspace or not. It looked at that time as if they were talking to him; it didn't occur to me that they weren't until the trainee said he didn't have Aircraft Y. Houston does this a lot; they'll change the altitude that is in the data block after accepting a handoff but before we actually switch the plane; which leads to confusion; did I already switch him; are they doing something with him? We might have diagnosed that Aircraft Y wasn't actually on frequency quicker if Houston hadn't changed the altitude.

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.