|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Locale Reference||atc facility : sct.tracon|
|Controlling Facilities||tracon : sct.tracon|
|Operator||common carrier : air carrier|
|Make Model Name||Commercial Fixed Wing|
|Operating Under FAR Part||Part 121|
|Flight Phase||descent : approach|
|Route In Use||arrival : on vectors|
|Affiliation||government : faa|
|Function||controller : approach|
|Qualification||controller : radar|
|Experience||controller military : 4.5|
controller radar : 16
controller time certified in position1 : 10
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Anomaly||other anomaly other|
|Independent Detector||other controllera|
|Resolutory Action||flight crew : executed go around|
|Problem Areas||Navigational Facility|
|Primary Problem||Navigational Facility|
While working downe radar position; I was responsible for about 4 arrs to lax. I lost use of the primary frequency 124.9 at approximately XA45. The last control instructions I issued prior to radio failure were to air carrier X to fly heading 330 degrees; descend and maintain 5000 ft. This is basically a base leg heading for traffic to the south complex at lax arriving from over sli VOR. The heading and altitude put these aircraft in confliction with arrs that are straight in to the north complex. My next transmission for air carrier X was to turn left heading 280 degrees; intercept runway 25R localizer; descend and maintain 3500 ft. This instruction would have been a prelude to the approach clearance and also provided for separation with traffic on the north final. No response from air carrier X so I say again. No response again. I try another aircraft and again no response. I notify the other final controller who issues instructions to conflicting aircraft on his final to expedite descent which establishes separation between the two. Meanwhile I utilize the emergency radio (ecvs) and turn air carrier X to intercept final. Now he is too high to complete the approach and results in a go around. I asked the supervisor to include on the facility log that the reason for the go around was because of the radio failure. The frequency was out for about 25 mins total. Maintenance told the supervisor that it was back but when I tried it I had the same problems. 5 mins later it was back completely. We have had numerous equipment issues at lax and sct. I never got an answer to my question about what caused the failure in the first place except that a technician was out at the site working on a UHF frequency and probably flipped the wrong switch.
Original NASA ASRS Text
Title: SCT CTLR DESCRIBED AN INCIDENT WHEN FREQ WAS TEMPORARILY LOST; CAUSING A POTENTIAL CONFLICT ON FINAL FOR LAX AND RESULTED IN A GAR.
Narrative: WHILE WORKING DOWNE RADAR POS; I WAS RESPONSIBLE FOR ABOUT 4 ARRS TO LAX. I LOST USE OF THE PRIMARY FREQ 124.9 AT APPROX XA45. THE LAST CTL INSTRUCTIONS I ISSUED PRIOR TO RADIO FAILURE WERE TO ACR X TO FLY HDG 330 DEGS; DSND AND MAINTAIN 5000 FT. THIS IS BASICALLY A BASE LEG HEADING FOR TFC TO THE S COMPLEX AT LAX ARRIVING FROM OVER SLI VOR. THE HDG AND ALT PUT THESE ACFT IN CONFLICTION WITH ARRS THAT ARE STRAIGHT IN TO THE N COMPLEX. MY NEXT XMISSION FOR ACR X WAS TO TURN L HDG 280 DEGS; INTERCEPT RWY 25R LOC; DSND AND MAINTAIN 3500 FT. THIS INSTRUCTION WOULD HAVE BEEN A PRELUDE TO THE APCH CLRNC AND ALSO PROVIDED FOR SEPARATION WITH TFC ON THE N FINAL. NO RESPONSE FROM ACR X SO I SAY AGAIN. NO RESPONSE AGAIN. I TRY ANOTHER ACFT AND AGAIN NO RESPONSE. I NOTIFY THE OTHER FINAL CTLR WHO ISSUES INSTRUCTIONS TO CONFLICTING ACFT ON HIS FINAL TO EXPEDITE DSCNT WHICH ESTABLISHES SEPARATION BTWN THE TWO. MEANWHILE I UTILIZE THE EMER RADIO (ECVS) AND TURN ACR X TO INTERCEPT FINAL. NOW HE IS TOO HIGH TO COMPLETE THE APCH AND RESULTS IN A GAR. I ASKED THE SUPVR TO INCLUDE ON THE FACILITY LOG THAT THE REASON FOR THE GAR WAS BECAUSE OF THE RADIO FAILURE. THE FREQ WAS OUT FOR ABOUT 25 MINS TOTAL. MAINT TOLD THE SUPVR THAT IT WAS BACK BUT WHEN I TRIED IT I HAD THE SAME PROBS. 5 MINS LATER IT WAS BACK COMPLETELY. WE HAVE HAD NUMEROUS EQUIP ISSUES AT LAX AND SCT. I NEVER GOT AN ANSWER TO MY QUESTION ABOUT WHAT CAUSED THE FAILURE IN THE FIRST PLACE EXCEPT THAT A TECHNICIAN WAS OUT AT THE SITE WORKING ON A UHF FREQ AND PROBABLY FLIPPED THE WRONG SWITCH.
Data retrieved from NASA's ASRS site as of January 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.