Narrative:

I was under an IFR clearance and under radar vectors to intercept the localizer to runway 17 at olm. I was maintaining 2500 ft. I was cleared for the ILS approach. I had selected the localizer frequency but did not 'FLIP-flop' the frequency from 'standby' to 'active' as I responded to the intercept heading call and made my turn. I interpreted my localizer indicator (not tuned to the proper frequency) to show I was intercepting the GS and began a descent. The approach controller called me and said I needed to maintain 2500 ft to the final fix and said he showed me at 1600 ft. I immediately noted the frequency problem, climbed to 2500 ft and completed the approach. The problem was mine: 1) not properly tuning and identing the frequency. 2) not confirming the fix. The airplane does not have DME and the mccord VOR has consistently been OTS for yrs. But I did not ask the controller to radar identify it for me. 3) I did not monitor the GS flag on the indicator. I have not flown this airplane or performed as single pilot for 3 months. I need to stay current, and pay closer attention to procedures and each of the 3 points above. I am glad the controller noticed the altitude. There was no intervening terrain along the approach but at a different airport this could have been a major problem.

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Original NASA ASRS Text

Title: A VERY EXPERIENCED PLT RPTED THAT HE WAS ATTEMPTING TO INTERCEPT THE LOC FOR RWY 17 AT OLM, BUT DID NOT REALIZE THE FREQ WAS NOT ENTERED PROPERLY, RESULTING IN A CFIT SIT.

Narrative: I WAS UNDER AN IFR CLRNC AND UNDER RADAR VECTORS TO INTERCEPT THE LOC TO RWY 17 AT OLM. I WAS MAINTAINING 2500 FT. I WAS CLRED FOR THE ILS APCH. I HAD SELECTED THE LOC FREQ BUT DID NOT 'FLIP-FLOP' THE FREQ FROM 'STANDBY' TO 'ACTIVE' AS I RESPONDED TO THE INTERCEPT HEADING CALL AND MADE MY TURN. I INTERPRETED MY LOC INDICATOR (NOT TUNED TO THE PROPER FREQ) TO SHOW I WAS INTERCEPTING THE GS AND BEGAN A DSCNT. THE APCH CTLR CALLED ME AND SAID I NEEDED TO MAINTAIN 2500 FT TO THE FINAL FIX AND SAID HE SHOWED ME AT 1600 FT. I IMMEDIATELY NOTED THE FREQ PROB, CLBED TO 2500 FT AND COMPLETED THE APCH. THE PROB WAS MINE: 1) NOT PROPERLY TUNING AND IDENTING THE FREQ. 2) NOT CONFIRMING THE FIX. THE AIRPLANE DOES NOT HAVE DME AND THE MCCORD VOR HAS CONSISTENTLY BEEN OTS FOR YRS. BUT I DID NOT ASK THE CTLR TO RADAR IDENT IT FOR ME. 3) I DID NOT MONITOR THE GS FLAG ON THE INDICATOR. I HAVE NOT FLOWN THIS AIRPLANE OR PERFORMED AS SINGLE PLT FOR 3 MONTHS. I NEED TO STAY CURRENT, AND PAY CLOSER ATTN TO PROCS AND EACH OF THE 3 POINTS ABOVE. I AM GLAD THE CTLR NOTICED THE ALT. THERE WAS NO INTERVENING TERRAIN ALONG THE APCH BUT AT A DIFFERENT ARPT THIS COULD HAVE BEEN A MAJOR PROB.

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.