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A B737 flight crew experiences a short 'terrain, terrain' warning without the 'pull-up' during an IMC night vectored approach to lax. Aircraft was under the class B floor at 22 mi DME on the ILS runway 24R localizer. Aircraft had come in over smo and had an extended downwind leg.
| Attributes | |
| ACN | 393257 |
| Time | |
| Date | 199802 |
| Day | Fri |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : lax |
| State Reference | CA |
| Altitude | msl bound lower : 2500 msl bound upper : 2500 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tracon : lax |
| Operator | common carrier : air carrier |
| Make Model Name | B737-300 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | cruise other descent : approach |
| Route In Use | arrival other enroute : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 240 flight time total : 11600 flight time type : 4500 |
| ASRS Report | 393257 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial |
| Events | |
| Anomaly | non adherence : far non adherence : published procedure other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified |
| Resolutory Action | none taken : anomaly accepted |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | Pilot Deviation Operational Deviation |
| Situations | |
| ATC Facility | procedure or policy : unspecified |
Narrative:
Two separate GPWS warnings while maneuvering on radar vectors for the ILS runway 24R at lax. Both occurred while in level flight at 2500 ft MSL (MVA). Conditions were night IMC with scattered rain showers. The first warning, one cycle of 'too low -- gear' occurred simultaneous with aircraft entering a heavy rain shower and on an extended downwind north of the localizer heading 100 degrees. The second warning, one cycle of 'terrain, terrain' occurred at 22.0 DME ioss while established on the localizer. Aircraft was clear of clouds with terrain visible. During both occurrences, aircraft was being hand flown in level flight +/-100 ft due to turbulence.
Original NASA ASRS Text
Title: A B737 FLC EXPERIENCES A SHORT 'TERRAIN, TERRAIN' WARNING WITHOUT THE 'PULL-UP' DURING AN IMC NIGHT VECTORED APCH TO LAX. ACFT WAS UNDER THE CLASS B FLOOR AT 22 MI DME ON THE ILS RWY 24R LOC. ACFT HAD COME IN OVER SMO AND HAD AN EXTENDED DOWNWIND LEG.
Narrative: TWO SEPARATE GPWS WARNINGS WHILE MANEUVERING ON RADAR VECTORS FOR THE ILS RWY 24R AT LAX. BOTH OCCURRED WHILE IN LEVEL FLT AT 2500 FT MSL (MVA). CONDITIONS WERE NIGHT IMC WITH SCATTERED RAIN SHOWERS. THE FIRST WARNING, ONE CYCLE OF 'TOO LOW -- GEAR' OCCURRED SIMULTANEOUS WITH ACFT ENTERING A HVY RAIN SHOWER AND ON AN EXTENDED DOWNWIND N OF THE LOC HDG 100 DEGS. THE SECOND WARNING, ONE CYCLE OF 'TERRAIN, TERRAIN' OCCURRED AT 22.0 DME IOSS WHILE ESTABLISHED ON THE LOC. ACFT WAS CLR OF CLOUDS WITH TERRAIN VISIBLE. DURING BOTH OCCURRENCES, ACFT WAS BEING HAND FLOWN IN LEVEL FLT +/-100 FT DUE TO TURB.
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.