Narrative:

I was the PNF. The flight was normal up until we began getting vectors for approach. Approach switched us and the new controller gave us a descent from 8000 ft to 7000 ft; a speed of 210 KTS; and an assigned heading. I was tuning in the ILS runway 24L frequencys in to both rmu's; but there were dashed lines where the frequencys should be. The first officer (PF) had a red 'X' on his navigation and no GS indication. I attempted multiple times to tune in the frequencys and correct the problem. At about that time we both noticed that the radios were quiet and the first officer stated that we had gone through the localizer course depicted on the mfd from the FMS. I asked ATC if we were supposed to intercept with no response. At that time we realized that we had lost communication also. I eventually pressed the test button on the rmu's and the frequencys came back. We contacted ATC and they informed us that they had been trying to reach us for 15 mi and gave us vectors back around to intercept. I informed them that we had had a radio problem but it was fixed now. From that point on; the flight was normal. Upon arrival at the gate while I was getting paperwork; maintenance came to the plane for a service check and the first officer questioned about the problem we had. Maintenance said that they would re-rack the navigation and communication. I feel that maybe there should be a procedure in the QRH about this due to the fact that the first officer said had this problem before. Supplemental information from acn 789793: I have had this problem once before in an EMB145. The last time it happened; only the navigation radios were affected; and we never were able to return them to normal operation. We were forced to make a visual approach in marginal VFR conditions. I believe this is an extreme safety hazard. There exists no training or QRH procedure for this situation. I have spoken to other pilots; and they too have seen dashes replace frequencys on the rmu. Nobody; even maintenance could offer a confident explanation or fix. I even brought the issue up in my last recurrent ground and the instructor had no input.

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Original NASA ASRS Text

Title: EMB145 FLT CREW REPORTS NAV AND COMM RADIO FAILURES DURING VECTORS FOR APPROACH.

Narrative: I WAS THE PNF. THE FLT WAS NORMAL UP UNTIL WE BEGAN GETTING VECTORS FOR APCH. APCH SWITCHED US AND THE NEW CTLR GAVE US A DSCNT FROM 8000 FT TO 7000 FT; A SPD OF 210 KTS; AND AN ASSIGNED HDG. I WAS TUNING IN THE ILS RWY 24L FREQS IN TO BOTH RMU'S; BUT THERE WERE DASHED LINES WHERE THE FREQS SHOULD BE. THE FO (PF) HAD A RED 'X' ON HIS NAV AND NO GS INDICATION. I ATTEMPTED MULTIPLE TIMES TO TUNE IN THE FREQS AND CORRECT THE PROB. AT ABOUT THAT TIME WE BOTH NOTICED THAT THE RADIOS WERE QUIET AND THE FO STATED THAT WE HAD GONE THROUGH THE LOC COURSE DEPICTED ON THE MFD FROM THE FMS. I ASKED ATC IF WE WERE SUPPOSED TO INTERCEPT WITH NO RESPONSE. AT THAT TIME WE REALIZED THAT WE HAD LOST COM ALSO. I EVENTUALLY PRESSED THE TEST BUTTON ON THE RMU'S AND THE FREQS CAME BACK. WE CONTACTED ATC AND THEY INFORMED US THAT THEY HAD BEEN TRYING TO REACH US FOR 15 MI AND GAVE US VECTORS BACK AROUND TO INTERCEPT. I INFORMED THEM THAT WE HAD HAD A RADIO PROB BUT IT WAS FIXED NOW. FROM THAT POINT ON; THE FLT WAS NORMAL. UPON ARR AT THE GATE WHILE I WAS GETTING PAPERWORK; MAINT CAME TO THE PLANE FOR A SVC CHK AND THE FO QUESTIONED ABOUT THE PROB WE HAD. MAINT SAID THAT THEY WOULD RE-RACK THE NAV AND COM. I FEEL THAT MAYBE THERE SHOULD BE A PROC IN THE QRH ABOUT THIS DUE TO THE FACT THAT THE FO SAID HAD THIS PROB BEFORE. SUPPLEMENTAL INFO FROM ACN 789793: I HAVE HAD THIS PROB ONCE BEFORE IN AN EMB145. THE LAST TIME IT HAPPENED; ONLY THE NAV RADIOS WERE AFFECTED; AND WE NEVER WERE ABLE TO RETURN THEM TO NORMAL OP. WE WERE FORCED TO MAKE A VISUAL APCH IN MARGINAL VFR CONDITIONS. I BELIEVE THIS IS AN EXTREME SAFETY HAZARD. THERE EXISTS NO TRAINING OR QRH PROC FOR THIS SITUATION. I HAVE SPOKEN TO OTHER PLTS; AND THEY TOO HAVE SEEN DASHES REPLACE FREQS ON THE RMU. NOBODY; EVEN MAINT COULD OFFER A CONFIDENT EXPLANATION OR FIX. I EVEN BROUGHT THE ISSUE UP IN MY LAST RECURRENT GROUND AND THE INSTRUCTOR HAD NO INPUT.

Data retrieved from NASA's ASRS site as of May 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.