Narrative:

I was on the return leg of a 2.3 hour flight to an avionics shop, where both radios had been checked because of numerous pilot squawks. One of the radios was replaced by a loaner from the shop. The aircraft did not have DME or area-navigation equipment. I was tracking the msn VOR inbound and using pilotage. I picked up msn ATIS as soon as possible (about 40 NM out) and started to look for one distinctive landmark which I wanted to report over on my initial call-up to msn approach. Unable to locate that landmark, I realized a similar-looking landmark (town and lake) in about a 20 NM distance. There was however an easily identifiable (big) airport next to that town which should not have been next to my landmark. Even though I had the msn airport in sight from 20 NM (which is the airport I trained at) I failed to realize that I must have passed my landmark and was already staring at my destination. At about 10 NM did I finally discover that msn was ahead and entered a 360 degree to call up approach without getting closer. After radar contact, the controller stated I was 9 mi from the field and should not ever call up that late again. ATC was hard to read on the loaner radio which was in use. The controller gave me a clearance containing a heading, runway to expect and altitude to maintain on my descent. Due to the bad radio I did not understand the altitude restr and read back the heading only. Even though I knew the controller must have said something else, I did not verify, mostly because it could have been something about my failure to call again and I felt already embarrassed and did not want to get into more exchanges with the controller. When I was descending through 2600 ft the controller asked to 'confirm level at 3000 ft.' I denied, leveled off. The controller explained the altitude restr was for traffic separation. It is unknown to me if other aircraft were close. It is still unclr to me why I did not recognize the very familiar msn airport earlier. Factors for the misperception were that I was tired during the entire flight and had not had enough sleep the night before. Shortly before approaching msn, I was cruising at 10500 ft MSL without oxygen which notably enhanced the tiredness. Maintaining VMC over a broken layer kept me from using pilotage during parts of the leg. A first-time passenger in the copilot seat was a distraction, too. I wrongly did not perceive myself being 'lost' when I was and did not make use of the dual VOR receivers to determine my position.

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Original NASA ASRS Text

Title: PVT PLT OF A C172 ENTERED CLASS C AIRSPACE WITHOUT FIRST CONTACTING APCH CTL. THEN, AFTER RECEIVING CLRNC, DSNDED FROM ASSIGNED ALT DUE TO NOT HEARING THE CLRNC CLRLY ON A NEWLY INSTALLED LOANER RADIO.

Narrative: I WAS ON THE RETURN LEG OF A 2.3 HR FLT TO AN AVIONICS SHOP, WHERE BOTH RADIOS HAD BEEN CHKED BECAUSE OF NUMEROUS PLT SQUAWKS. ONE OF THE RADIOS WAS REPLACED BY A LOANER FROM THE SHOP. THE ACFT DID NOT HAVE DME OR AREA-NAV EQUIP. I WAS TRACKING THE MSN VOR INBOUND AND USING PILOTAGE. I PICKED UP MSN ATIS AS SOON AS POSSIBLE (ABOUT 40 NM OUT) AND STARTED TO LOOK FOR ONE DISTINCTIVE LANDMARK WHICH I WANTED TO RPT OVER ON MY INITIAL CALL-UP TO MSN APCH. UNABLE TO LOCATE THAT LANDMARK, I REALIZED A SIMILAR-LOOKING LANDMARK (TOWN AND LAKE) IN ABOUT A 20 NM DISTANCE. THERE WAS HOWEVER AN EASILY IDENTIFIABLE (BIG) ARPT NEXT TO THAT TOWN WHICH SHOULD NOT HAVE BEEN NEXT TO MY LANDMARK. EVEN THOUGH I HAD THE MSN ARPT IN SIGHT FROM 20 NM (WHICH IS THE ARPT I TRAINED AT) I FAILED TO REALIZE THAT I MUST HAVE PASSED MY LANDMARK AND WAS ALREADY STARING AT MY DEST. AT ABOUT 10 NM DID I FINALLY DISCOVER THAT MSN WAS AHEAD AND ENTERED A 360 DEG TO CALL UP APCH WITHOUT GETTING CLOSER. AFTER RADAR CONTACT, THE CTLR STATED I WAS 9 MI FROM THE FIELD AND SHOULD NOT EVER CALL UP THAT LATE AGAIN. ATC WAS HARD TO READ ON THE LOANER RADIO WHICH WAS IN USE. THE CTLR GAVE ME A CLRNC CONTAINING A HEADING, RWY TO EXPECT AND ALT TO MAINTAIN ON MY DSCNT. DUE TO THE BAD RADIO I DID NOT UNDERSTAND THE ALT RESTR AND READ BACK THE HEADING ONLY. EVEN THOUGH I KNEW THE CTLR MUST HAVE SAID SOMETHING ELSE, I DID NOT VERIFY, MOSTLY BECAUSE IT COULD HAVE BEEN SOMETHING ABOUT MY FAILURE TO CALL AGAIN AND I FELT ALREADY EMBARRASSED AND DID NOT WANT TO GET INTO MORE EXCHANGES WITH THE CTLR. WHEN I WAS DSNDING THROUGH 2600 FT THE CTLR ASKED TO 'CONFIRM LEVEL AT 3000 FT.' I DENIED, LEVELED OFF. THE CTLR EXPLAINED THE ALT RESTR WAS FOR TFC SEPARATION. IT IS UNKNOWN TO ME IF OTHER ACFT WERE CLOSE. IT IS STILL UNCLR TO ME WHY I DID NOT RECOGNIZE THE VERY FAMILIAR MSN ARPT EARLIER. FACTORS FOR THE MISPERCEPTION WERE THAT I WAS TIRED DURING THE ENTIRE FLT AND HAD NOT HAD ENOUGH SLEEP THE NIGHT BEFORE. SHORTLY BEFORE APCHING MSN, I WAS CRUISING AT 10500 FT MSL WITHOUT OXYGEN WHICH NOTABLY ENHANCED THE TIREDNESS. MAINTAINING VMC OVER A BROKEN LAYER KEPT ME FROM USING PILOTAGE DURING PARTS OF THE LEG. A FIRST-TIME PAX IN THE COPLT SEAT WAS A DISTR, TOO. I WRONGLY DID NOT PERCEIVE MYSELF BEING 'LOST' WHEN I WAS AND DID NOT MAKE USE OF THE DUAL VOR RECEIVERS TO DETERMINE MY POS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.