A B727 CREW DOES NOT SWITCH TO DTW TWR FOR A LNDG CLRNC.

Narrative

THIS WAS THE LAST LEG OF A 5 LEG DAY. THE 4TH LEG WAS A SCHEDULED DEADHEAD TO ELIMINATE AN 8 IN 24 PROB (8 HRS OF FLYING IN 24 HRS). APCHING DTW; APCH CTL TOLD US WE WERE #1; KEEP YOUR SPD UP; WHICH WE DID. AS IT WAS CLR AND A MILLION AND WE WERE APCHING THE ARPT EXPEDITIOUSLY; WE SPENT A GOOD DEAL OF TIME OUTSIDE THE AIRPLANE LOOKING FOR THE ARPT AND CLRING FOR OTHER TFC. THE CAPT KEPT THE FO INFORMED OF AN ACFT DEPARTING FROM OUR RWY AND CALLED IT AIRBORNE. THE FO MADE A GREAT LNDG; WE EXITED THE RWY AND ASKED TWR FOR THE GND FREQ. WE ALL SAT IN STUNNED SILENCE AS THE APCH CTLR SAID 'FLT XXX; YOU'RE STILL ON APCH CTL.' WE COULD NOT BELIEVE WHAT WE HAD JUST DONE. LOOKING BACK; WE COULD NOT REMEMBER APCH CTL SENDING US TO TWR FREQ ON FINAL (NOT THAT THAT'S A GOOD EXCUSE -- IT ISN'T). FATIGUE WAS DEFINITELY A FACTOR IN MY CASE; SOMEHOW THE DEADHEAD IN THE MIDDLE OF THE DAY MADE ME MORE MENTALLY TIRED THAN I THINK I WOULD HAVE BEEN HAD I FLOWN THAT LEG. I RECOMMEND THAT ALL SCHEDULED DEADHEADS OCCUR ON EITHER THE 1ST OR LAST LEG OF THE DAY. ALSO; AT THE LAST AIRLINE I WAS AT; IT WAS COMMON PRACTICE TO SWITCH THE ALT ALERT TO 49000 FT WHEN CLRED TO LAND. I RECOMMEND A UNIFORM INDICATION; PERHAPS EVEN A SPECIALIZED INDICATOR; TO INDICATE 'CLRED TO LAND' IN THE COCKPIT. LASTLY; BUT MOST IMPORTANTLY; IT'S IMPORTANT TO NOT PAY JUST LIP SVC TO ALL THOSE VERBAL CHKS WE DO AS WE PROCEED DOWN FINAL. THEY ARE VITALLY IMPORTANT.