Narrative:

I am the first officer and the PF. Cleared runway 27L approach. Approach control told us to contact tower at willt, 120.75. At willt we called, no answer. We tried 126.9, no answer. Unable to contact tower on any of the published frequencys. Initiated a go around. Vectors around to an uneventful approach and landing, using tower frequency 127.92. WX was VFR and no conflict occurred to our knowledge. Ord was using tower frequency 132.7 and 127.92 -- neither of which are published either by NOTAM, ATIS, or field report. Is there a way when tower is using unpublished frequencys that they be broadcast on ATIS or NOTAM? Callback conversation with reporter revealed the following information: reporter indicated the reason for the use of the unpublished frequencys was, according to the ground controller, due to interference problems on the tower frequencys. Reporter said they had heard the approach controller give the old frequency and then correct it with the new frequency to a couple of aircraft ahead of them. Analyst made a callback to the facility and learned that the only time the unpublished frequencys are used is when there is a stuck microphone or some other situation causing a temporary interruption to the frequencys. Reporter indicated they do not put it on the ATIS because of the short term use.

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Original NASA ASRS Text

Title: ACR B727 GAR WHEN UNABLE TO COM WITH TWR ON EITHER OF 2 PUBLISHED FREQS. TWR WAS USING 2 UNPUBLISHED FREQS. RPTR STATED THIS INFO WAS NOT ON THE ATIS.

Narrative: I AM THE FO AND THE PF. CLRED RWY 27L APCH. APCH CTL TOLD US TO CONTACT TWR AT WILLT, 120.75. AT WILLT WE CALLED, NO ANSWER. WE TRIED 126.9, NO ANSWER. UNABLE TO CONTACT TWR ON ANY OF THE PUBLISHED FREQS. INITIATED A GAR. VECTORS AROUND TO AN UNEVENTFUL APCH AND LNDG, USING TWR FREQ 127.92. WX WAS VFR AND NO CONFLICT OCCURRED TO OUR KNOWLEDGE. ORD WAS USING TWR FREQ 132.7 AND 127.92 -- NEITHER OF WHICH ARE PUBLISHED EITHER BY NOTAM, ATIS, OR FIELD RPT. IS THERE A WAY WHEN TWR IS USING UNPUBLISHED FREQS THAT THEY BE BROADCAST ON ATIS OR NOTAM? CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR INDICATED THE REASON FOR THE USE OF THE UNPUBLISHED FREQS WAS, ACCORDING TO THE GND CTLR, DUE TO INTERFERENCE PROBS ON THE TWR FREQS. RPTR SAID THEY HAD HEARD THE APCH CTLR GIVE THE OLD FREQ AND THEN CORRECT IT WITH THE NEW FREQ TO A COUPLE OF ACFT AHEAD OF THEM. ANALYST MADE A CALLBACK TO THE FACILITY AND LEARNED THAT THE ONLY TIME THE UNPUBLISHED FREQS ARE USED IS WHEN THERE IS A STUCK MIKE OR SOME OTHER SIT CAUSING A TEMPORARY INTERRUPTION TO THE FREQS. RPTR INDICATED THEY DO NOT PUT IT ON THE ATIS BECAUSE OF THE SHORT TERM USE.

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.