 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
An air carrier B757 flight crew had to switch to the alternate pitot static source to recover the captain's instruments, but they were unable to inhibit the GPWS warning system so it sounded the 'don't sink' warning during their approach at destination.
| Attributes | |
| ACN | 385762 |
| Time | |
| Date | 199711 |
| Day | Thu |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : lax |
| State Reference | CA |
| Altitude | agl bound lower : 200 agl bound upper : 2000 |
| Environment | |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tower : lax tower : dfw |
| Operator | common carrier : air carrier |
| Make Model Name | B757 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | descent : approach |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 385762 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument |
| Events | |
| Anomaly | aircraft equipment problem : less severe other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | none taken : detected after the fact |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
Narrative:
We had obtained a 10000 ft runway (4R) at boston for departure, which gave us more time to react at V1 '141 KTS' when captain's pitot-static instruments failed. First officer performed the takeoff in his usual outstanding professional manner as a solo until captain's flight instruments could be recovered by use of the alternate air data source. On landing at lax the aural warning 'don't sink' was present from 2000 ft AGL down to 200 ft AGL, while aircraft was in proper landing confign and on GS. Because the warning was so loud, our communications were dangerously compromised and we were unable to stop the GPWS warning in spite of hitting all the GPWS inhibit buttons. Why no information about how to silence erroneous GPWS warnings?
Original NASA ASRS Text
Title: AN ACR B757 FLC HAD TO SWITCH TO THE ALTERNATE PITOT STATIC SOURCE TO RECOVER THE CAPT'S INSTS, BUT THEY WERE UNABLE TO INHIBIT THE GPWS WARNING SYS SO IT SOUNDED THE 'DON'T SINK' WARNING DURING THEIR APCH AT DEST.
Narrative: WE HAD OBTAINED A 10000 FT RWY (4R) AT BOSTON FOR DEP, WHICH GAVE US MORE TIME TO REACT AT V1 '141 KTS' WHEN CAPT'S PITOT-STATIC INSTS FAILED. FO PERFORMED THE TKOF IN HIS USUAL OUTSTANDING PROFESSIONAL MANNER AS A SOLO UNTIL CAPT'S FLT INSTS COULD BE RECOVERED BY USE OF THE ALTERNATE AIR DATA SOURCE. ON LNDG AT LAX THE AURAL WARNING 'DON'T SINK' WAS PRESENT FROM 2000 FT AGL DOWN TO 200 FT AGL, WHILE ACFT WAS IN PROPER LNDG CONFIGN AND ON GS. BECAUSE THE WARNING WAS SO LOUD, OUR COMS WERE DANGEROUSLY COMPROMISED AND WE WERE UNABLE TO STOP THE GPWS WARNING IN SPITE OF HITTING ALL THE GPWS INHIBIT BUTTONS. WHY NO INFO ABOUT HOW TO SILENCE ERRONEOUS GPWS WARNINGS?
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.