Air Traffic Control Fully Certified
Communication Breakdown; Situational Awareness
ATC Issue All Types; Inflight Event / Encounter CFTT / CFIT
General None Reported / Taken
Procedure; Human Factors
Aircraft X departed ZZZ and was instructed to fly heading 070. Aircraft X requested to go off frequency to acquire the ATIS information for ZZZ1. I instructed Aircraft X to squawk a new code and then approved his request to go off frequency and to advise when back on. Aircraft X was about 10 miles from a 4;000 FT MVA area and I felt he would be able to gather the information and return to frequency in time for me to turn him. While Aircraft X was off frequency; I was adjusting his data block and accidentally terminated control and removed him from the STARS. I re-entered the information but I did so incorrectly. I put his call sign as Aircraft Y. About a minute or two later Aircraft X was approaching the boundary for the 4;000 FT MVA. I reached out to see if he was back on frequency yet; but I called out for Aircraft Y because of my earlier mistake. Another Controller asked me if I was watching Aircraft Y and I replied that they were off frequency. I tried to reach aircraft on Guard; but again I called out Aircraft Y. Several minutes later Aircraft X called up and asked; 'Did you mean Aircraft X?' I realized my error and replied; 'Aircraft X climb and maintain 4;000 FT fly heading 340.' His present heading was towards an even higher MVA. I asked Aircraft X if he had acquired the ATIS. He said that he did not; so I just read the ATIS to him myself. Aircraft X reached 4;000 FT safely and then was vectored and landed safely at ZZZ1. I should have either put Aircraft X at a higher altitude or put him on a safer heading. I could also have just read the ATIS information to the pilot initially.
TRACON Controller approved a frequency change to an IFR aircraft to acquire the ATIS information which led to a below MVA event.