PA27 LIGHT TWIN CFI MAKES A VISUAL APCH TO THE WRONG ARPT WHEN CHOOSING CWA VERSUS AUW WHICH WAS 9 MI N OF CWA; WI.

Narrative

I WAS ON AN IFR FLT PLAN HDG N OFF STE VOR ON V-63 TO AUW. I WAS CLRED DOWN TO 3500 FT AND MSP CLRED ME TO AUW FOR THE VISUAL. WHEN HE DID HE ALSO REPLIED RADAR CONTACT LOST WHILE I WAS DSNDING AND TO CANCEL IFR WHEN I HAD THE ARPT. AT THIS TIME EVEN THOUGH I HAD THE RNAV SET UP FOR WAUSUA. I WENT FOR THE VISUAL. WHILE THE DME WAS COUNTING DOWN; I STARTED FEELING NAUSEOUS AND WAS FEELING SEVERE CRAMPS STARTING AT THAT TIME. NEEDING TO GET DOWN; I WENT AHEAD AND CANCELED IFR AND STARTED DOWN AFTER I THOUGHT I SAW WAUSUA ARPT. I LISTENED TO WX AT AUW AND STARTED ENTERING A LONG DOWNWIND. AFTER I CROSSED THE THRESHOLD WHICH NOW WAS RWY 26; I NOTICED THE RWY NUMBER DID NOT COINCIDE WITH MY CHART. I KEPT TURNING TO THE L TO LOOK AT THE N/S RWY WHEN I REALIZED A COMMUTER WAS ON A LONG FINAL FOR RWY 17. I MISSED SEEING IT BEFORE I TURNED BECAUSE MY VISOR ON THE ACFT WOULD NOT STAY UP. AS I TURNED; IS WHEN I SAW IT OUT THE R SIDE FRONT WINDSHIELD. I IMMEDIATELY TURNED R TO STAY OFF HIS L SIDE AND TURNED NE. NOW NEEDING TO GET DOWN BECAUSE NOW I WAS REALLY FEELING SICK; I CTRED VOR NEEDLE AND THEN AT THAT TIME I REALIZED I ENTERED INTO CWA'S CLASS D AIRSPACE WITHOUT 2-WAY CONTACT AND ALMOST CROSSED IN FRONT OF AN AIRLINE COMMUTER. I VISUALLY IDENTED THE WRONG ARPT IS THE REASON == WAUSAU IS A FEW (9) MI N OF CWA. I HAVE HEARD OTHERS ACTUALLY LNDG AT CWA BY MISTAKE. I WAS GOING TO AND HAD PLANNED TO STAY ON THE NEEDLES SO I; TOO; WOULD NOT MAKE THAT MISTAKE. BUT NOT FEELING WELL AND GETTING WORSE IN A TWIN; I WAS PUSHING MYSELF DOWN TO THAT ARPT. LACK OF SLEEP; LONG HRS WITH NO BREAKS AT WORK; BEING A FULL TIME FLT INSTRUCTOR; 10-12 HRS AT WORK 5 DAYS A WEEK; 2 1/2 YRS; STUDENTS BACK-TO-BACK 2 HR SESSIONS; MAYBE 1/2 HR BREAK 1 TIME; PAYS A TOLL -- THEN BEING SICK ON TOP OF IT. WHEN MOST CTLRS ARE GOING TO LOSE SOMEONE THEY USUALLY GIVE THEM SOME REF TO THEIR DISTANCE FROM SOMETHING. WITH ALL THE HORROR STORIES AT THESE 2 ARPTS; I WOULD THINK THAT; WOULD HELP BEFORE LOSING CONTACT. IF CTLR WOULD HAVE SAID; '10 MI S CWA; DSND TO 3500 FT'; INSTEAD OF DSND 3500 FT; PRIOR TO CONTACT LOSS; CANCEL WITH ME WITH ARPT IN SIGHT. THAT WAS THE NEXT ARPT AND BEING A NICE DAY; CANCELED AND FORCING THE LETDOWN TO HURRY THE PROCESS.