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B757 flight crew reports map display freezing as aircraft enters holding at ard on the PHLBO2 into ewr. Raw data is used for remainder of flight.
| Attributes | |
| ACN | 782814 |
| Time | |
| Date | 200804 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | navaid : ard.vor |
| State Reference | NJ |
| Altitude | msl single value : 10000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : n90.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | B757-200 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other other vortac |
| Route In Use | arrival star : phlbo |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| ASRS Report | 782814 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| ASRS Report | 782815 |
| Events | |
| Anomaly | aircraft equipment problem : less severe non adherence : clearance other spatial deviation |
| Independent Detector | other flight crewa |
| Resolutory Action | controller : issued advisory flight crew : returned to original clearance |
| Consequence | other |
| Supplementary | |
| Problem Areas | Aircraft |
| Primary Problem | Aircraft |
Narrative:
Our flight was tracking ewr phlbo STAR inbound to somto fix when we noticed our map display had froze. ATC instructed to hold at ard fix. Our map display indicated 3.5 NM south of ard but raw data showed us left of course and 1.0 NM north of ard. We asked controller to verify and he concurred. Continued to hold using raw data and ATC issued vector to intercept ILS to runway 4R. Map display remained froze throughout uneventful landing. Entered write-up in logbook. Callback conversation with reporter acn 782815 revealed the following information: the reporter stated that the map freeze was apparently caused by dual FMC failure as the CDU would not accept any inputs after the initial indication of trouble. The CDU displayed an 'unable to update' message just prior to the map freeze. Simultaneous inputs from both pilots may also have been part of the problem. Maintenance action was to power down both fmcs and restart which cleared the problem.
Original NASA ASRS Text
Title: B757 FLT CREW REPORTS MAP DISPLAY FREEZING AS ACFT ENTERS HOLDING AT ARD ON THE PHLBO2 INTO EWR. RAW DATA IS USED FOR REMAINDER OF FLIGHT.
Narrative: OUR FLT WAS TRACKING EWR PHLBO STAR INBOUND TO SOMTO FIX WHEN WE NOTICED OUR MAP DISPLAY HAD FROZE. ATC INSTRUCTED TO HOLD AT ARD FIX. OUR MAP DISPLAY INDICATED 3.5 NM S OF ARD BUT RAW DATA SHOWED US L OF COURSE AND 1.0 NM N OF ARD. WE ASKED CTLR TO VERIFY AND HE CONCURRED. CONTINUED TO HOLD USING RAW DATA AND ATC ISSUED VECTOR TO INTERCEPT ILS TO RWY 4R. MAP DISPLAY REMAINED FROZE THROUGHOUT UNEVENTFUL LNDG. ENTERED WRITE-UP IN LOGBOOK. CALLBACK CONVERSATION WITH RPTR ACN 782815 REVEALED THE FOLLOWING INFO: THE REPORTER STATED THAT THE MAP FREEZE WAS APPARENTLY CAUSED BY DUAL FMC FAILURE AS THE CDU WOULD NOT ACCEPT ANY INPUTS AFTER THE INITIAL INDICATION OF TROUBLE. THE CDU DISPLAYED AN 'UNABLE TO UPDATE' MESSAGE JUST PRIOR TO THE MAP FREEZE. SIMULTANEOUS INPUTS FROM BOTH PLTS MAY ALSO HAVE BEEN PART OF THE PROB. MAINTENANCE ACTION WAS TO POWER DOWN BOTH FMCS AND RESTART WHICH CLEARED THE PROBLEM.
Data retrieved from NASA's ASRS site as of May 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.