Narrative:

Talking to stockton approach, descended from 11000 ft to 4000 ft and assigned a 170 degree heading, approximately 10 mi from modesto airport. Given another approach frequency of 120.95. PNF read back 120.45, which was never caught. Made several attempts to contact new stockton approach. Talked about going back to last frequency, but due to congestion of previous frequency, proximity to airport and number of targets on TCASII, thought we would be able to talk to a controller more quickly if we contacted modesto tower, which we did. Told the tower where we were and that we were unable to contact approach. He asked us if we had the field in sight, which we did. He cleared us for a visual approach to runway 28R and told us to call a 2 mi right base, and that there was a commuter on a left base for the same runway. As we descended into a right base, we asked for the commuter's location. The tower controller told us to cancel the approach clearance, climb to 3000 ft on a 140 degree heading and contact approach. Approach told us our last assigned clearance was to maintain 4000 ft on a 170 degree heading and that there was commuter traffic for the airport. At no time were we ever told that there was a conflict, nor did we receive any TA or RA on the TCASII. Approach gave us a couple more vectors, asked if we had the airport in sight (which we did) and cleared us for a visual to runway 28R. When he switched us to mod tower, he gave us a number to call. Spoke to the supervisor who was very helpful. He listened to the tapes, asked why we did what we did. Said that his controller was in error for not catching our incorrect frequency readback, and that the tower controller should not have accepted us but should have sent us to the correct frequency. Also, we should have gone back to the last good frequency. He also made no mention of any traffic conflict and did say that there was no problem.

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Original NASA ASRS Text

Title: LJ45 ON VECTOR FOR APCH TO SCK HAS A FREQ MIX-UP, CALLS TWR, AND FINALLY RETURNED TO APCH CTL FOR A NEW VECTOR.

Narrative: TALKING TO STOCKTON APCH, DSNDED FROM 11000 FT TO 4000 FT AND ASSIGNED A 170 DEG HDG, APPROX 10 MI FROM MODESTO ARPT. GIVEN ANOTHER APCH FREQ OF 120.95. PNF READ BACK 120.45, WHICH WAS NEVER CAUGHT. MADE SEVERAL ATTEMPTS TO CONTACT NEW STOCKTON APCH. TALKED ABOUT GOING BACK TO LAST FREQ, BUT DUE TO CONGESTION OF PREVIOUS FREQ, PROX TO ARPT AND NUMBER OF TARGETS ON TCASII, THOUGHT WE WOULD BE ABLE TO TALK TO A CTLR MORE QUICKLY IF WE CONTACTED MODESTO TWR, WHICH WE DID. TOLD THE TWR WHERE WE WERE AND THAT WE WERE UNABLE TO CONTACT APCH. HE ASKED US IF WE HAD THE FIELD IN SIGHT, WHICH WE DID. HE CLRED US FOR A VISUAL APCH TO RWY 28R AND TOLD US TO CALL A 2 MI R BASE, AND THAT THERE WAS A COMMUTER ON A L BASE FOR THE SAME RWY. AS WE DSNDED INTO A R BASE, WE ASKED FOR THE COMMUTER'S LOCATION. THE TWR CTLR TOLD US TO CANCEL THE APCH CLRNC, CLB TO 3000 FT ON A 140 DEG HDG AND CONTACT APCH. APCH TOLD US OUR LAST ASSIGNED CLRNC WAS TO MAINTAIN 4000 FT ON A 170 DEG HDG AND THAT THERE WAS COMMUTER TFC FOR THE ARPT. AT NO TIME WERE WE EVER TOLD THAT THERE WAS A CONFLICT, NOR DID WE RECEIVE ANY TA OR RA ON THE TCASII. APCH GAVE US A COUPLE MORE VECTORS, ASKED IF WE HAD THE ARPT IN SIGHT (WHICH WE DID) AND CLRED US FOR A VISUAL TO RWY 28R. WHEN HE SWITCHED US TO MOD TWR, HE GAVE US A NUMBER TO CALL. SPOKE TO THE SUPVR WHO WAS VERY HELPFUL. HE LISTENED TO THE TAPES, ASKED WHY WE DID WHAT WE DID. SAID THAT HIS CTLR WAS IN ERROR FOR NOT CATCHING OUR INCORRECT FREQ READBACK, AND THAT THE TWR CTLR SHOULD NOT HAVE ACCEPTED US BUT SHOULD HAVE SENT US TO THE CORRECT FREQ. ALSO, WE SHOULD HAVE GONE BACK TO THE LAST GOOD FREQ. HE ALSO MADE NO MENTION OF ANY TFC CONFLICT AND DID SAY THAT THERE WAS NO 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.