B737-300 suffers faulty gear warning lights.

Attributes
ACN	778386
Time
Date	200803
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 2500
Aircraft 1
Controlling Facilities	tower : zzz.tower
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : n/s
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 220 flight time total : 18000 flight time type : 6000
ASRS Report	778386
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : gear safe lights other flight crewa
Resolutory Action	flight crew : executed go around flight crew : overcame equipment problem flight crew : declared emergency
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance ATC Human Performance
Primary Problem	Aircraft

Narrative:

When the gear was extended for approach; the nose gear green light did not illuminate. I quickly changed one of the light bulbs with a working main gear light bulb. I also tested the lights with push-to-test and test switch. The green light would not illuminate. The red nose gear light was extinguished. Therefore; as I recall; the nose gear would be down and locked. However; I had enough fuel to break off the approach and make sure before landing. I got the flight manual out and ran the checklist; put the gear down and check the down lock through the nose gear view port. The red lines were lined up. I notified tower that we were ready for the approach and anticipated a normal landing. Tower asked if we wanted the trucks and I said yes only as a precaution that we anticipated a normal landing. Tower also asked for souls on board and fuel on board. I contacted the lead flight attendant and gave a quick explanation of what it was; what to expect (normal landing); but be ready; and how long to landing. We landed without incident and turned off at taxiway. I then talked to maintenance and dispatch on the phone and found out that I believe the tower had declared an emergency for us. I told dispatch that we had not officially declared an emergency.

Original NASA ASRS Text

Title: B737-300 SUFFERS FAULTY GEAR WARNING LIGHTS.

Narrative: WHEN THE GEAR WAS EXTENDED FOR APCH; THE NOSE GEAR GREEN LIGHT DID NOT ILLUMINATE. I QUICKLY CHANGED ONE OF THE LIGHT BULBS WITH A WORKING MAIN GEAR LIGHT BULB. I ALSO TESTED THE LIGHTS WITH PUSH-TO-TEST AND TEST SWITCH. THE GREEN LIGHT WOULD NOT ILLUMINATE. THE RED NOSE GEAR LIGHT WAS EXTINGUISHED. THEREFORE; AS I RECALL; THE NOSE GEAR WOULD BE DOWN AND LOCKED. HOWEVER; I HAD ENOUGH FUEL TO BREAK OFF THE APCH AND MAKE SURE BEFORE LNDG. I GOT THE FLT MANUAL OUT AND RAN THE CHKLIST; PUT THE GEAR DOWN AND CHK THE DOWN LOCK THROUGH THE NOSE GEAR VIEW PORT. THE RED LINES WERE LINED UP. I NOTIFIED TWR THAT WE WERE READY FOR THE APCH AND ANTICIPATED A NORMAL LNDG. TWR ASKED IF WE WANTED THE TRUCKS AND I SAID YES ONLY AS A PRECAUTION THAT WE ANTICIPATED A NORMAL LNDG. TWR ALSO ASKED FOR SOULS ON BOARD AND FUEL ON BOARD. I CONTACTED THE LEAD FLT ATTENDANT AND GAVE A QUICK EXPLANATION OF WHAT IT WAS; WHAT TO EXPECT (NORMAL LNDG); BUT BE READY; AND HOW LONG TO LNDG. WE LANDED WITHOUT INCIDENT AND TURNED OFF AT TXWY. I THEN TALKED TO MAINT AND DISPATCH ON THE PHONE AND FOUND OUT THAT I BELIEVE THE TWR HAD DECLARED AN EMER FOR US. I TOLD DISPATCH THAT WE HAD NOT OFFICIALLY DECLARED AN EMER.

Data retrieved from NASA's ASRS site as of May 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.