Narrative:

This situation occurred during an IFR flight from poc to sba. While wbound on V-186, level at 6000 ft MSL, bur departure, 134.2 MHZ, handed us off to mugu approach, 128.65 MHZ. We established radio contact with mugu as required. (That was, as it turned out, our first and last communication with mugu). We continued wbound along V-186, in VMC. After an estimated 5 to 10 mins, we were approaching kwang intersection, the initial approach fix for the VOR runway 25 approach into sba, without having received any further radio communication from mugu approach. At this point, we made several attempts to contact mugu, all without success -- we could, however, hear other traffic on the frequency, including a cherokee also trying to reestablish contact with mugu. Having not received any reply from mugu, we switched directly to sba approach frequency 124.5 MHZ, and established radio communication with them. Sba immediately instructed us to turn left to heading 180 degrees to avoid traffic approaching kwang from the south, at the same altitude. We had visual contact with this traffic, although sba approach never queried us about that. Conclusions: 1) a problem is indicated with the mugu 128.65 MHZ facilities equipment, which causes radio contact with them to be lost. 2) also, had sba approach queried us about the VMC, and the other traffic approaching kwang, then that 'conflict' could have been handled with less drama. Later during the same flight described in situation #1, another unusual event occurred. While inbound on the VOR runway 25 approach to sba, near zacks, sba tower told us we were 1 mi left of the final approach course, and instructed us to turn right to re-intercept the final. At the time we received that instruction, however, our VOR needle was centered, and I could confirm visually outside (due to the VMC), that we were centered on the VOR final approach course. When we rolled out on the extended runway centerline for runway 25, it became clear that sba tower had actually turned us off of the VOR final approach course. We could determine this conclusively, because we were at that point, 2 to 3 mi from the runway and not 1/2 mi from the threshold, which is where we should have intercepted the extended runway centerline on the VOR final approach course, and also where the missed approach point is located. Callback conversation with reporter revealed the following information: atm at sba TRACON stated the frequency problem at ntd approach control has been idented and investigated. FAA frequency management says live with the problem and will not change the frequency. Problem is caused by LORAN interference.

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Original NASA ASRS Text

Title: SMA X LOST COM ON FREQ 128.65 WITH NTD APCH. ACFT UNABLE TO HEAR NTD APCH AT KWANG INTXN.

Narrative: THIS SIT OCCURRED DURING AN IFR FLT FROM POC TO SBA. WHILE WBOUND ON V-186, LEVEL AT 6000 FT MSL, BUR DEP, 134.2 MHZ, HANDED US OFF TO MUGU APCH, 128.65 MHZ. WE ESTABLISHED RADIO CONTACT WITH MUGU AS REQUIRED. (THAT WAS, AS IT TURNED OUT, OUR FIRST AND LAST COM WITH MUGU). WE CONTINUED WBOUND ALONG V-186, IN VMC. AFTER AN ESTIMATED 5 TO 10 MINS, WE WERE APCHING KWANG INTXN, THE INITIAL APCH FIX FOR THE VOR RWY 25 APCH INTO SBA, WITHOUT HAVING RECEIVED ANY FURTHER RADIO COM FROM MUGU APCH. AT THIS POINT, WE MADE SEVERAL ATTEMPTS TO CONTACT MUGU, ALL WITHOUT SUCCESS -- WE COULD, HOWEVER, HEAR OTHER TFC ON THE FREQ, INCLUDING A CHEROKEE ALSO TRYING TO REESTABLISH CONTACT WITH MUGU. HAVING NOT RECEIVED ANY REPLY FROM MUGU, WE SWITCHED DIRECTLY TO SBA APCH FREQ 124.5 MHZ, AND ESTABLISHED RADIO COM WITH THEM. SBA IMMEDIATELY INSTRUCTED US TO TURN L TO HDG 180 DEGS TO AVOID TFC APCHING KWANG FROM THE S, AT THE SAME ALT. WE HAD VISUAL CONTACT WITH THIS TFC, ALTHOUGH SBA APCH NEVER QUERIED US ABOUT THAT. CONCLUSIONS: 1) A PROB IS INDICATED WITH THE MUGU 128.65 MHZ FACILITIES EQUIP, WHICH CAUSES RADIO CONTACT WITH THEM TO BE LOST. 2) ALSO, HAD SBA APCH QUERIED US ABOUT THE VMC, AND THE OTHER TFC APCHING KWANG, THEN THAT 'CONFLICT' COULD HAVE BEEN HANDLED WITH LESS DRAMA. LATER DURING THE SAME FLT DESCRIBED IN SIT #1, ANOTHER UNUSUAL EVENT OCCURRED. WHILE INBOUND ON THE VOR RWY 25 APCH TO SBA, NEAR ZACKS, SBA TWR TOLD US WE WERE 1 MI L OF THE FINAL APCH COURSE, AND INSTRUCTED US TO TURN R TO RE-INTERCEPT THE FINAL. AT THE TIME WE RECEIVED THAT INSTRUCTION, HOWEVER, OUR VOR NEEDLE WAS CENTERED, AND I COULD CONFIRM VISUALLY OUTSIDE (DUE TO THE VMC), THAT WE WERE CENTERED ON THE VOR FINAL APCH COURSE. WHEN WE ROLLED OUT ON THE EXTENDED RWY CTRLINE FOR RWY 25, IT BECAME CLR THAT SBA TWR HAD ACTUALLY TURNED US OFF OF THE VOR FINAL APCH COURSE. WE COULD DETERMINE THIS CONCLUSIVELY, BECAUSE WE WERE AT THAT POINT, 2 TO 3 MI FROM THE RWY AND NOT 1/2 MI FROM THE THRESHOLD, WHICH IS WHERE WE SHOULD HAVE INTERCEPTED THE EXTENDED RWY CTRLINE ON THE VOR FINAL APCH COURSE, AND ALSO WHERE THE MISSED APCH POINT IS LOCATED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: ATM AT SBA TRACON STATED THE FREQ PROB AT NTD APCH CTL HAS BEEN IDENTED AND INVESTIGATED. FAA FREQ MGMNT SAYS LIVE WITH THE PROB AND WILL NOT CHANGE THE FREQ. PROB IS CAUSED BY LORAN INTERFERENCE.

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.