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A DC9-30 on approach at 4000 ft declared an emergency due to a nose gear unsafe light caused by a nose gear proximity sensor target failure.
| Attributes | |
| ACN | 412964 |
| Time | |
| Date | 199808 |
| Day | Sun |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : ind |
| State Reference | IN |
| Altitude | msl bound lower : 4000 msl bound upper : 4000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : ind tower : ord |
| Operator | common carrier : air carrier |
| Make Model Name | DC-9 30 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | descent : approach landing other other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 180 flight time total : 9000 flight time type : 2300 |
| ASRS Report | 412964 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial |
| Events | |
| Anomaly | aircraft equipment problem : critical other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : declared emergency other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
Narrative:
On gear extension heard loud pop and received a nose gear unsafe light. Executed a go around with gear extended. Performed company emergency extension procedures -- no help. Contacted company dispatch and maintenance control, cycled gear -- no help. First officer unable to determine through view port whether the nose gear was down and locked. Declared an emergency, briefed flight attendants and passenger. Landed with smooth touchdown. Pinned gear and had aircraft towed to gate. All crew members used excellent CRM and passenger remained calm throughout. This was my second occurrence with this in 4 months. Spoke with company concerning that and they mentioned that the system was being redesigned. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was a DC9-30 and the fleet was changing over from micro switch gear position sensing to proximity sensing and the nose gear lock sensor target has a high failure rate. The reporter stated that 10 failures have occurred with the sensor target either vibrating out of position or falling off.
Original NASA ASRS Text
Title: A DC9-30 ON APCH AT 4000 FT DECLARED AN EMER DUE TO A NOSE GEAR UNSAFE LIGHT CAUSED BY A NOSE GEAR PROX SENSOR TARGET FAILURE.
Narrative: ON GEAR EXTENSION HEARD LOUD POP AND RECEIVED A NOSE GEAR UNSAFE LIGHT. EXECUTED A GAR WITH GEAR EXTENDED. PERFORMED COMPANY EMER EXTENSION PROCS -- NO HELP. CONTACTED COMPANY DISPATCH AND MAINT CTL, CYCLED GEAR -- NO HELP. FO UNABLE TO DETERMINE THROUGH VIEW PORT WHETHER THE NOSE GEAR WAS DOWN AND LOCKED. DECLARED AN EMER, BRIEFED FLT ATTENDANTS AND PAX. LANDED WITH SMOOTH TOUCHDOWN. PINNED GEAR AND HAD ACFT TOWED TO GATE. ALL CREW MEMBERS USED EXCELLENT CRM AND PAX REMAINED CALM THROUGHOUT. THIS WAS MY SECOND OCCURRENCE WITH THIS IN 4 MONTHS. SPOKE WITH COMPANY CONCERNING THAT AND THEY MENTIONED THAT THE SYS WAS BEING REDESIGNED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A DC9-30 AND THE FLEET WAS CHANGING OVER FROM MICRO SWITCH GEAR POS SENSING TO PROX SENSING AND THE NOSE GEAR LOCK SENSOR TARGET HAS A HIGH FAILURE RATE. THE RPTR STATED THAT 10 FAILURES HAVE OCCURRED WITH THE SENSOR TARGET EITHER VIBRATING OUT OF POS OR FALLING OFF.
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.