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B737 crew lost both the captain's and first officer's localizer and GS signals in IMC in atl class B on vector to final.
| Attributes | |
| ACN | 617318 |
| Time | |
| Date | 200405 |
| Day | Thu |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : atl.airport |
| State Reference | GA |
| Altitude | msl single value : 3500 |
| Environment | |
| Flight Conditions | IMC |
| Weather Elements | other |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : a80.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | B737 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | ils localizer & glide slope : 9r |
| Flight Phase | descent : approach descent : intermediate altitude |
| Route In Use | approach : instrument precision arrival : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 200 flight time total : 16000 flight time type : 900 |
| ASRS Report | 617318 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Events | |
| Anomaly | aircraft equipment problem : critical inflight encounter : weather other spatial deviation other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : loc, 65 flags other flight crewa other flight crewb |
| Resolutory Action | controller : issued new clearance controller : provided flight assist flight crew : exited adverse environment |
| Consequence | other other |
| Supplementary | |
| Problem Areas | Flight Crew Human Performance Aircraft |
| Primary Problem | Aircraft |
Narrative:
When being vectored for the ILS approach to runway 9R in atlanta, the copilot's ILS failed. Both localizer and GS flags were in view. We selected the 'a' autoplt so that he could couple the autoplt to the captain's ILS. While on a vector of 060 degrees to intercept the localizer, we noticed that the ADF needle was not falling off to the left as we expected and that the captain's localizer was not capturing. Suddenly both localizer and GS flags appeared on the captain's ADI. I called approach and reported a loss of all navigation instruments. He immediately gave us a vector to the southeast (back to the localizer). As he was asking us that type of approach we wanted to fly and we were trying to ascertain what type of approach we could fly, the captain's ILS captured the localizer and GS. We told approach we could continue with an ILS and proceeded to land, but after coming out of the clouds, we again lost all ILS navigation. After reaching the gate, our mechanics investigated the system and found a serious problem with the navigation antenna that they were not able to correct. Because of the current and forecast ceilings at our next 2 cities, our flts were cancelled and the aircraft grounded until parts could be found. We did not receive any traffic conflicts on TCASII, but recognizing the loss of our navaids took so long that we must have been close to a conflict.
Original NASA ASRS Text
Title: B737 CREW LOST BOTH THE CAPT'S AND FO'S LOC AND GS SIGNALS IN IMC IN ATL CLASS B ON VECTOR TO FINAL.
Narrative: WHEN BEING VECTORED FOR THE ILS APCH TO RWY 9R IN ATLANTA, THE COPLT'S ILS FAILED. BOTH LOC AND GS FLAGS WERE IN VIEW. WE SELECTED THE 'A' AUTOPLT SO THAT HE COULD COUPLE THE AUTOPLT TO THE CAPT'S ILS. WHILE ON A VECTOR OF 060 DEGS TO INTERCEPT THE LOC, WE NOTICED THAT THE ADF NEEDLE WAS NOT FALLING OFF TO THE L AS WE EXPECTED AND THAT THE CAPT'S LOC WAS NOT CAPTURING. SUDDENLY BOTH LOC AND GS FLAGS APPEARED ON THE CAPT'S ADI. I CALLED APCH AND RPTED A LOSS OF ALL NAV INSTS. HE IMMEDIATELY GAVE US A VECTOR TO THE SE (BACK TO THE LOC). AS HE WAS ASKING US THAT TYPE OF APCH WE WANTED TO FLY AND WE WERE TRYING TO ASCERTAIN WHAT TYPE OF APCH WE COULD FLY, THE CAPT'S ILS CAPTURED THE LOC AND GS. WE TOLD APCH WE COULD CONTINUE WITH AN ILS AND PROCEEDED TO LAND, BUT AFTER COMING OUT OF THE CLOUDS, WE AGAIN LOST ALL ILS NAV. AFTER REACHING THE GATE, OUR MECHS INVESTIGATED THE SYS AND FOUND A SERIOUS PROB WITH THE NAV ANTENNA THAT THEY WERE NOT ABLE TO CORRECT. BECAUSE OF THE CURRENT AND FORECAST CEILINGS AT OUR NEXT 2 CITIES, OUR FLTS WERE CANCELLED AND THE ACFT GNDED UNTIL PARTS COULD BE FOUND. WE DID NOT RECEIVE ANY TFC CONFLICTS ON TCASII, BUT RECOGNIZING THE LOSS OF OUR NAVAIDS TOOK SO LONG THAT WE MUST HAVE BEEN CLOSE TO A CONFLICT.
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.