Narrative:

During approach to fkl airport in VMC, we were told by yng approach to expect a visual approach. Yng was working more than one frequency, but we could only hear the controller's xmissions on our frequency. We saw the rotating beacon at fkl at 15 mi out. I started to activate the pilot controled lighting with #2 communication. After 2 attempts I determined the pilot controled lighting to be inoperative. At the same time I reported to yng that I had the field in sight, however, I had left the transmit switch on #2, so my transmission was on unicom. At about this time we heard an approach clearance from yng. The first officer (PF) thought it was for us and began a descent to set up a pattern for landing. Initial altitude was 3200 ft MSL, at 2600 ft MSL I realized my communication switch was on wrong transmitter. I switched to yng, and confirmed that we had airport in sight. He asked if we were cleared for the approach. At this point I realized we had been transmitting on the wrong frequency. We were then cleared for the approach and landed at fkl. Better vigilance on radio management is a must. Possibly when ATC is working more than one frequency, we should hear both sides of the xmissions or, working more than one frequency should be eliminated.

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Original NASA ASRS Text

Title: FLC LEFT ASSIGNED ALT WITHOUT COORDINATING WITH ATC. PLT TALKING ON RADIOS WAS TALKING ON THE WRONG RADIO.

Narrative: DURING APCH TO FKL ARPT IN VMC, WE WERE TOLD BY YNG APCH TO EXPECT A VISUAL APCH. YNG WAS WORKING MORE THAN ONE FREQ, BUT WE COULD ONLY HEAR THE CTLR'S XMISSIONS ON OUR FREQ. WE SAW THE ROTATING BEACON AT FKL AT 15 MI OUT. I STARTED TO ACTIVATE THE PLT CTLED LIGHTING WITH #2 COM. AFTER 2 ATTEMPTS I DETERMINED THE PLT CTLED LIGHTING TO BE INOP. AT THE SAME TIME I RPTED TO YNG THAT I HAD THE FIELD IN SIGHT, HOWEVER, I HAD LEFT THE XMIT SWITCH ON #2, SO MY XMISSION WAS ON UNICOM. AT ABOUT THIS TIME WE HEARD AN APCH CLRNC FROM YNG. THE FO (PF) THOUGHT IT WAS FOR US AND BEGAN A DSCNT TO SET UP A PATTERN FOR LNDG. INITIAL ALT WAS 3200 FT MSL, AT 2600 FT MSL I REALIZED MY COM SWITCH WAS ON WRONG XMITTER. I SWITCHED TO YNG, AND CONFIRMED THAT WE HAD ARPT IN SIGHT. HE ASKED IF WE WERE CLRED FOR THE APCH. AT THIS POINT I REALIZED WE HAD BEEN XMITTING ON THE WRONG FREQ. WE WERE THEN CLRED FOR THE APCH AND LANDED AT FKL. BETTER VIGILANCE ON RADIO MGMNT IS A MUST. POSSIBLY WHEN ATC IS WORKING MORE THAN ONE FREQ, WE SHOULD HEAR BOTH SIDES OF THE XMISSIONS OR, WORKING MORE THAN ONE FREQ SHOULD BE ELIMINATED.

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.