PLTDEV OPDEV INVOLVING ACR AND UGA.

Narrative

WE WERE LNDG AT PHX. LNDG RWY 8L. THE LAST XMISSION FROM APCH CTL WAS 'CLRED FOR THE VISUAL; MAINTAIN 160 KTS TO THE HWY.' I WAS THE PF. ON ABOUT A 1 1/2 TO 2 MI FINAL I ASKED THE CAPT (PNF) FOR CONFIRMATION THAT WE WERE CLRED TO LAND. THE CAPT THEN REALIZED THAT WE WERE STILL ON APCH FREQ. THE CAPT THEN ASKED APCH IF THEY WANTED US ON TWR FREQ. APCH CTL AT THAT TIME TOLD US TO SWITCH TO TWR; WHICH WE THEN DID. WHILE THIS WAS HAPPENING; I NOTICED AN ACFT PULLING OUT ONTO THE RWY. TWR THEN HAD US DO A GAR; AND TO CONTACT DEP. DEP HAD US MAKE L TFC FOR RWY 8L. ON DOWNWIND WE WERE ONCE AGAIN CLRED FOR THE VISUAL APCH. ONCE AGAIN; WE WERE NEVER TOLD TO CONTACT TWR. AS WE TURNED BASE WE ASKED APCH IF THEY WANTED US TO CHANGE TO TWR FREQ. AT THAT TIME; THEY HAD US SWITCH AND WE WERE THEN CLRED TO LAND. ON BOTH OCCASIONS; ME AND THE CAPT DO NOT RECALL BEING TOLD TO CONTACT TWR; UNTIL WE ASKED IF THEY WANTED US TO. I'M NOT SURE HOW THE PROB AROSE BUT I SERIOUSLY BELIEVE THAT WAS MISCOM BTWN APCH AND TWR.