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ATC switched the ILS to the opposite end of the runway during DC10 ILS approach causing them to have erroneous GS readings and going too low too soon causing an ATC low altitude alert.
| Attributes | |
| ACN | 474692 |
| Time | |
| Date | 200006 |
| Day | Thu |
| Local Time Of Day | 0001 To 0600 |
| Place | |
| Locale Reference | airport : lax.airport |
| State Reference | CA |
| Altitude | msl bound lower : 1500 msl bound upper : 2500 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tracon : sct.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | DC-10 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | ils localizer & glide slope : 24r |
| Flight Phase | descent : approach |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : flight engineer pilot : atp |
| Experience | flight time last 90 days : 50 flight time total : 12000 flight time type : 7000 |
| ASRS Report | 474692 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp pilot : commercial pilot : flight engineer |
| Experience | flight time last 90 days : 150 flight time total : 10000 flight time type : 1500 |
| ASRS Report | 474597 |
| Events | |
| Anomaly | non adherence : published procedure other anomaly other |
| Independent Detector | atc equipment : msaw aircraft equipment other aircraft equipment : ils indicators other flight crewa other flight crewb other other : 3 |
| Resolutory Action | controller : issued new clearance flight crew : executed missed approach other |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Problem Areas | ATC Human Performance ATC Facility |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Flight air carrier X hnl-lax on may/xa/00. On descent, ATC advised 'there will be 1 or 2 approachs to runway 24R, then lax will switch around to runway 6L for arrs. Expect an ILS runway 24R.' we intercepted the localizer (108.5) to runway 24R at approximately 10 NM at 2500 ft, autoplt on and coupled to the localizer. Captain's ADI showed we were 2 dots high on the GS. The first officer's ADI had a GS flag. The so alertly noted the aural identify on captain's VHF navigation was different than first officer. Meanwhile, the captain descended to 1500 ft trying to intercept the GS from above. As it became apparent something was clearly wrong, the captain leveled off the aircraft at 1500 ft MSL. We queried ATC about the ILS signal and they immediately responded they had a low altitude warning on us (inside romen LOM). We were advised to turn to 280 degrees, climb to 3000 ft for an ILS runway 6R. Supplemental information from acn 474597: after landing on runway 6L we asked the lax tower controller 'what happened? Did you change the frequency too soon?' (meaning change the airport around from a west landing operation to an east landing operation.) 'yeah,' he said. 'That's what happened.' apparently we had intercepted a back course from runway 6L on approach to runway 24R. Our different GS indications and getting different frequency idents are more difficult to understand.
Original NASA ASRS Text
Title: ATC SWITCHED THE ILS TO THE OPPOSITE END OF THE RWY DURING DC10 ILS APCH CAUSING THEM TO HAVE ERRONEOUS GS READINGS AND GOING TOO LOW TOO SOON CAUSING AN ATC LOW ALT ALERT.
Narrative: FLT ACR X HNL-LAX ON MAY/XA/00. ON DSCNT, ATC ADVISED 'THERE WILL BE 1 OR 2 APCHS TO RWY 24R, THEN LAX WILL SWITCH AROUND TO RWY 6L FOR ARRS. EXPECT AN ILS RWY 24R.' WE INTERCEPTED THE LOC (108.5) TO RWY 24R AT APPROX 10 NM AT 2500 FT, AUTOPLT ON AND COUPLED TO THE LOC. CAPT'S ADI SHOWED WE WERE 2 DOTS HIGH ON THE GS. THE FO'S ADI HAD A GS FLAG. THE SO ALERTLY NOTED THE AURAL IDENT ON CAPT'S VHF NAV WAS DIFFERENT THAN FO. MEANWHILE, THE CAPT DSNDED TO 1500 FT TRYING TO INTERCEPT THE GS FROM ABOVE. AS IT BECAME APPARENT SOMETHING WAS CLRLY WRONG, THE CAPT LEVELED OFF THE ACFT AT 1500 FT MSL. WE QUERIED ATC ABOUT THE ILS SIGNAL AND THEY IMMEDIATELY RESPONDED THEY HAD A LOW ALT WARNING ON US (INSIDE ROMEN LOM). WE WERE ADVISED TO TURN TO 280 DEGS, CLB TO 3000 FT FOR AN ILS RWY 6R. SUPPLEMENTAL INFO FROM ACN 474597: AFTER LNDG ON RWY 6L WE ASKED THE LAX TWR CTLR 'WHAT HAPPENED? DID YOU CHANGE THE FREQ TOO SOON?' (MEANING CHANGE THE ARPT AROUND FROM A W LNDG OP TO AN E LNDG OP.) 'YEAH,' HE SAID. 'THAT'S WHAT HAPPENED.' APPARENTLY WE HAD INTERCEPTED A BACK COURSE FROM RWY 6L ON APCH TO RWY 24R. OUR DIFFERENT GS INDICATIONS AND GETTING DIFFERENT FREQ IDENTS ARE MORE DIFFICULT TO UNDERSTAND.
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.