Plane returned to PEN after discovering a technical fault. Here is the audio clip between AK6242 and Butterworth ATC
https://www.dropbox.com/s/l3rxsw1zakfcnyc/WMKB-Dec-28-2014-0900Z.mp3?dl=0
Go to http://archive-server.liveatc.net/wmkb/WMKB-App-Sep-14-2012-2330Z.mp3, scroll to 29:45. WMKB ATC is requesting for the reason of emergency landing. Too technical for me!