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Flight crew of B737-500 experience egpws terrain warnings during approach in visual conditions to cle. Suspect inappropriate warning the result of an FMS map shift shortly before final approach.
| Attributes | |
| ACN | 690069 |
| Time | |
| Date | 200603 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : cle.airport |
| State Reference | OH |
| Altitude | msl single value : 500 |
| Environment | |
| Flight Conditions | VMC |
| Aircraft 1 | |
| Controlling Facilities | tower : cle.tower |
| Operator | common carrier : air carrier |
| Make Model Name | B737-500 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | ils localizer & glide slope : 24r |
| Flight Phase | descent : approach |
| Route In Use | approach : visual |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Experience | flight time last 90 days : 150 flight time total : 7500 flight time type : 5230 |
| ASRS Report | 690069 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Experience | flight time last 90 days : 240 flight time total : 10000 flight time type : 400 |
| ASRS Report | 689900 |
| Events | |
| Anomaly | aircraft equipment problem : critical non adherence : published procedure |
| Independent Detector | aircraft equipment : gpws other flight crewa other flight crewb |
| Resolutory Action | none taken : anomaly accepted |
| Consequence | other |
| Supplementary | |
| Problem Areas | Aircraft Flight Crew Human Performance |
| Primary Problem | Aircraft |
Narrative:
Entering a modified base leg for a visual to runway 24R at cle the crew noticed that there was a significant map shift (at least 2-3 mi). The first officer was still in automatic. The captain was flying with GS capture and localizer capture at approximately 1400 ft. Just after the 500 ft call; the egpws began calling out 'caution terrain; caution terrain.' at this point the crew confirmed visually there was no terrain problem and realizing the cautions were due to the map shift we continued the approach. Due to the workload in flying the last 200 ft to a crosswind landing; the captain was unable to push the egpws terrain override switch; thus the GPWS 'terrain; terrain; pull up; pull up; pull up' was activated. Knowing the reason for the warning and confirming the final descent checklist was complete the captain completed the landing. Very uncomfortable landing with the warning going off. Looking back; go around might have been better to give time to override terrain warnings and allow for a more comfortable approach to keep better situational awareness. At gate; called mr X and made an information report and talked to next captain to ensure everyone was in the loop for possible aircraft discrepancy.
Original NASA ASRS Text
Title: FLT CREW OF B737-500 EXPERIENCE EGPWS TERRAIN WARNINGS DURING APCH IN VISUAL CONDITIONS TO CLE. SUSPECT INAPPROPRIATE WARNING THE RESULT OF AN FMS MAP SHIFT SHORTLY BEFORE FINAL APCH.
Narrative: ENTERING A MODIFIED BASE LEG FOR A VISUAL TO RWY 24R AT CLE THE CREW NOTICED THAT THERE WAS A SIGNIFICANT MAP SHIFT (AT LEAST 2-3 MI). THE FO WAS STILL IN AUTO. THE CAPT WAS FLYING WITH GS CAPTURE AND LOC CAPTURE AT APPROX 1400 FT. JUST AFTER THE 500 FT CALL; THE EGPWS BEGAN CALLING OUT 'CAUTION TERRAIN; CAUTION TERRAIN.' AT THIS POINT THE CREW CONFIRMED VISUALLY THERE WAS NO TERRAIN PROB AND REALIZING THE CAUTIONS WERE DUE TO THE MAP SHIFT WE CONTINUED THE APCH. DUE TO THE WORKLOAD IN FLYING THE LAST 200 FT TO A XWIND LNDG; THE CAPT WAS UNABLE TO PUSH THE EGPWS TERRAIN OVERRIDE SWITCH; THUS THE GPWS 'TERRAIN; TERRAIN; PULL UP; PULL UP; PULL UP' WAS ACTIVATED. KNOWING THE REASON FOR THE WARNING AND CONFIRMING THE FINAL DSCNT CHKLIST WAS COMPLETE THE CAPT COMPLETED THE LNDG. VERY UNCOMFORTABLE LNDG WITH THE WARNING GOING OFF. LOOKING BACK; GAR MIGHT HAVE BEEN BETTER TO GIVE TIME TO OVERRIDE TERRAIN WARNINGS AND ALLOW FOR A MORE COMFORTABLE APCH TO KEEP BETTER SITUATIONAL AWARENESS. AT GATE; CALLED MR X AND MADE AN INFO RPT AND TALKED TO NEXT CAPT TO ENSURE EVERYONE WAS IN THE LOOP FOR POSSIBLE ACFT DISCREPANCY.
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.