Narrative:

The incident took place on a VOR approach to runway 26 at cma airport. The reported ceiling was 1500 ft and cloud tops extended to approximately 4500 ft. Conditions were VFR up until the approach started. The PIC had received his instrument rating in the last 6 months and did not have any actual IMC time. Approach cleared us to descend from 5000 ft to 4000 ft approximately 18 NM from the airport and then cleared us for the VOR approach. The initial descent from 5000 ft immediately put the aircraft into the cloud layer. Very soon after; we were handed off to the tower. At approximately 12 NM from the airport; tower reported that we were approximately 4 NM off the approach course and we needed to switch back to approach for guidance. At this same time; the PIC noted that the aircraft heading was 17 degrees to the left of the approach course and that there was a 2 DOT deviation on the CDI left-of-course. The final approach course was 247. The 2 DOT deviation was reported to approach. Approach requested that we turn to a heading of 270 degrees; climb back to 4000 ft; and report reestablished on the approach course before continuing the approach. Secondly; we should contact tower again at the intersection that was 5.5 NM from the airport. All of the actions above were completed by the PIC without incident. The PIC broke out of the cloud layer at approximately 1000 ft MSL and approximately 1 mi north of the approach course with the VOR CDI centered. A normal approach and landing took place afterwards. Although this incident ended uneventfully; the PIC is thankful that approach caught the course deviation early. The PIC believes the following factors led to this incident: 1) relative lack of experience in actual IFR conditions. 2) a mild case of the 'leans' that occurred just after entering the cloud layer. 3) fixation on the primary attitude instruments to counteract the mild disorientation experienced in the cloud layer. The CDI indicator deviation was overlooked in the scan. 4) the non-precision nature of the VOR approach. To prevent this problem in the future; the PIC will take the following actions: 1) more 'under the hood' practice and; preferably; more actual IMC time with an instructor on board. 2) the trip to cma is a regular trip taken by the PIC. If similar WX conditions occur on future trips; the PIC will divert to nearby oxr that has an ILS approach.

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Original NASA ASRS Text

Title: AN IMC C172 PLT CONDUCTING A VOR APCH EXPERIENCED VERTIGO AND DEVIATED FROM THE FINAL COURSE. HE CORRECTED BACK AFTER TRACON ASSISTANCE GIVEN.

Narrative: THE INCIDENT TOOK PLACE ON A VOR APCH TO RWY 26 AT CMA ARPT. THE RPTED CEILING WAS 1500 FT AND CLOUD TOPS EXTENDED TO APPROX 4500 FT. CONDITIONS WERE VFR UP UNTIL THE APCH STARTED. THE PIC HAD RECEIVED HIS INSTRUMENT RATING IN THE LAST 6 MONTHS AND DID NOT HAVE ANY ACTUAL IMC TIME. APCH CLRED US TO DSND FROM 5000 FT TO 4000 FT APPROX 18 NM FROM THE ARPT AND THEN CLRED US FOR THE VOR APCH. THE INITIAL DSCNT FROM 5000 FT IMMEDIATELY PUT THE ACFT INTO THE CLOUD LAYER. VERY SOON AFTER; WE WERE HANDED OFF TO THE TWR. AT APPROX 12 NM FROM THE ARPT; TWR RPTED THAT WE WERE APPROX 4 NM OFF THE APCH COURSE AND WE NEEDED TO SWITCH BACK TO APCH FOR GUIDANCE. AT THIS SAME TIME; THE PIC NOTED THAT THE ACFT HEADING WAS 17 DEGS TO THE LEFT OF THE APCH COURSE AND THAT THERE WAS A 2 DOT DEVIATION ON THE CDI LEFT-OF-COURSE. THE FINAL APCH COURSE WAS 247. THE 2 DOT DEVIATION WAS RPTED TO APCH. APCH REQUESTED THAT WE TURN TO A HDG OF 270 DEGS; CLB BACK TO 4000 FT; AND RPT REESTABLISHED ON THE APCH COURSE BEFORE CONTINUING THE APCH. SECONDLY; WE SHOULD CONTACT TWR AGAIN AT THE INTERSECTION THAT WAS 5.5 NM FROM THE ARPT. ALL OF THE ACTIONS ABOVE WERE COMPLETED BY THE PIC WITHOUT INCIDENT. THE PIC BROKE OUT OF THE CLOUD LAYER AT APPROX 1000 FT MSL AND APPROX 1 MI N OF THE APCH COURSE WITH THE VOR CDI CENTERED. A NORMAL APCH AND LNDG TOOK PLACE AFTERWARDS. ALTHOUGH THIS INCIDENT ENDED UNEVENTFULLY; THE PIC IS THANKFUL THAT APCH CAUGHT THE COURSE DEVIATION EARLY. THE PIC BELIEVES THE FOLLOWING FACTORS LED TO THIS INCIDENT: 1) RELATIVE LACK OF EXPERIENCE IN ACTUAL IFR CONDITIONS. 2) A MILD CASE OF THE 'LEANS' THAT OCCURRED JUST AFTER ENTERING THE CLOUD LAYER. 3) FIXATION ON THE PRIMARY ATTITUDE INSTRUMENTS TO COUNTERACT THE MILD DISORIENTATION EXPERIENCED IN THE CLOUD LAYER. THE CDI INDICATOR DEV WAS OVERLOOKED IN THE SCAN. 4) THE NON-PRECISION NATURE OF THE VOR APCH. TO PREVENT THIS PROB IN THE FUTURE; THE PIC WILL TAKE THE FOLLOWING ACTIONS: 1) MORE 'UNDER THE HOOD' PRACTICE AND; PREFERABLY; MORE ACTUAL IMC TIME WITH AN INSTRUCTOR ON BOARD. 2) THE TRIP TO CMA IS A REGULAR TRIP TAKEN BY THE PIC. IF SIMILAR WX CONDITIONS OCCUR ON FUTURE TRIPS; THE PIC WILL DIVERT TO NEARBY OXR THAT HAS AN ILS APCH.

Data retrieved from NASA's ASRS site as of January 2009 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.