 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
When the flight crew extended the gear on a B737-300 for landing, they did not receive the 3 green lights that indicate gear extension. The gear was manually extended and verified and an emergency was declared. Landing was uneventful. Maintenance follow-up found that the lights module (which provided 3 green gear down indication) had short circuited.
| Attributes | |
| ACN | 331465 |
| Time | |
| Date | 199603 |
| Day | Mon |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : lax |
| State Reference | CA |
| Altitude | msl bound lower : 1500 msl bound upper : 1500 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tracon : lax artcc : zob |
| Operator | common carrier : air carrier |
| Make Model Name | B737-300 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | descent : approach landing other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : commercial pilot : cfi pilot : flight engineer pilot : instrument |
| Experience | flight time last 90 days : 220 flight time total : 11000 flight time type : 1400 |
| ASRS Report | 331465 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial |
| Events | |
| Anomaly | aircraft equipment problem : critical |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : overcame equipment problem flight crew : declared emergency other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
Narrative:
Upon placing the landing gear lever down, the 3 green lights did not illuminate. We accomplished the emergency gear lowering procedure, and declared an emergency. We landed uneventfully. Callback conversation with reporter revealed the following information: this B737-300 captain did not receive a gear indication, but he was certain that the gear was down because of the associated drag and the fact that the gear warning horn did not sound when landing flaps were selected. Maintenance personnel discovered that the test switch module that controls the gear lights (indicates 'test,' 'dim,' or 'bright'), had short circuited. The circuitry for some of the fuel boost pumps and the window heat were also affected.
Original NASA ASRS Text
Title: WHEN THE FLC EXTENDED THE GEAR ON A B737-300 FOR LNDG, THEY DID NOT RECEIVE THE 3 GREEN LIGHTS THAT INDICATE GEAR EXTENSION. THE GEAR WAS MANUALLY EXTENDED AND VERIFIED AND AN EMER WAS DECLARED. LNDG WAS UNEVENTFUL. MAINT FOLLOW-UP FOUND THAT THE LIGHTS MODULE (WHICH PROVIDED 3 GREEN GEAR DOWN INDICATION) HAD SHORT CIRCUITED.
Narrative: UPON PLACING THE LNDG GEAR LEVER DOWN, THE 3 GREEN LIGHTS DID NOT ILLUMINATE. WE ACCOMPLISHED THE EMER GEAR LOWERING PROC, AND DECLARED AN EMER. WE LANDED UNEVENTFULLY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THIS B737-300 CAPT DID NOT RECEIVE A GEAR INDICATION, BUT HE WAS CERTAIN THAT THE GEAR WAS DOWN BECAUSE OF THE ASSOCIATED DRAG AND THE FACT THAT THE GEAR WARNING HORN DID NOT SOUND WHEN LNDG FLAPS WERE SELECTED. MAINT PERSONNEL DISCOVERED THAT THE TEST SWITCH MODULE THAT CTLS THE GEAR LIGHTS (INDICATES 'TEST,' 'DIM,' OR 'BRIGHT'), HAD SHORT CIRCUITED. THE CIRCUITRY FOR SOME OF THE FUEL BOOST PUMPS AND THE WINDOW HEAT WERE ALSO AFFECTED.
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.