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Miss of an arrival crossing restr attributed to an FMS map shift by an air carrier crew.
| Attributes | |
| ACN | 530399 |
| Time | |
| Date | 200111 |
| Day | Sun |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | navaid : pdz.vortac |
| State Reference | CA |
| Altitude | msl bound lower : 6300 msl bound upper : 10000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tracon : sct.tracon tower : acy.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B767-300 and 300 ER |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other other vortac |
| Flight Phase | descent : approach |
| Route In Use | arrival star : pdz4 |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 171 flight time total : 20757 flight time type : 5222 |
| ASRS Report | 530399 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Events | |
| Anomaly | aircraft equipment problem : less severe altitude deviation : crossing restriction not met other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : fms error warn other controllera other controllerb |
| Resolutory Action | controller : issued new clearance |
| Supplementary | |
| Problem Areas | Aircraft Flight Crew Human Performance ATC Human Performance |
| Primary Problem | Aircraft |
Narrative:
Descending on pdz for arrival the FMS became lost and map shifts occurred. The vertical track error was flashing back and forth between 20 ft and +830 ft. In VNAV with the center autoplt on, the aircraft started the descent as we crossed over arnes. The vertical track error was still showing high and the descent increased. Then the first officer said we were fast and supposed to be at 10000 at arnes. I looked at the HSI and sure enough we were again at arnes, only this time in a rapid descent. I asked the first officer to call ATC but the controller asked us to verify our altitude. The first officer said 6300 and asked ATC where he showed us on radar. ATC said right over arnes. Then ATC said maintain present altitude and cleared us for the approach. The rest of the approach was normal.
Original NASA ASRS Text
Title: MISS OF AN ARR CROSSING RESTR ATTRIBUTED TO AN FMS MAP SHIFT BY AN AIR CARRIER CREW.
Narrative: DESCENDING ON PDZ FOR ARR THE FMS BECAME LOST AND MAP SHIFTS OCCURRED. THE VERTICAL TRACK ERROR WAS FLASHING BACK AND FORTH BETWEEN 20 FT AND +830 FT. IN VNAV WITH THE CTR AUTOPLT ON, THE ACFT STARTED THE DESCENT AS WE CROSSED OVER ARNES. THE VERTICAL TRACK ERROR WAS STILL SHOWING HIGH AND THE DESCENT INCREASED. THEN THE FO SAID WE WERE FAST AND SUPPOSED TO BE AT 10000 AT ARNES. I LOOKED AT THE HSI AND SURE ENOUGH WE WERE AGAIN AT ARNES, ONLY THIS TIME IN A RAPID DESCENT. I ASKED THE FO TO CALL ATC BUT THE CTLR ASKED US TO VERIFY OUR ALT. THE FO SAID 6300 AND ASKED ATC WHERE HE SHOWED US ON RADAR. ATC SAID RIGHT OVER ARNES. THEN ATC SAID MAINTAIN PRESENT ALT AND CLRED US FOR THE APCH. THE REST OF THE APCH WAS NORMAL.
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.