Commuter has no green light for left main gear when gear extended.

Attributes
ACN	234170
Time
Date	199302
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : bwi
State Reference	MD
Altitude	msl bound lower : 2500 msl bound upper : 2500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bwi tower : sdf
Operator	common carrier : air carrier
Make Model Name	Light Transport, High Wing, 2 Turboprop Eng
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 21700 flight time type : 130
ASRS Report	234170
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

The gear was lowered and the left main green light remained out. Permission for a low pass over runway 33R was given and the tower reported all 3 gear appeared down and locked. Caution/APU lights test showed the light not operating. The landing gear indicator malfunction procedure was done and the alternate indicators showed 3 green lights. I believed that the bulbs were burned out, however, I declared an emergency and went through the precautions for an emergency landing. Emergency equipment was standing by as we made a normal landing. The mechanics replaced both bulbs in the left main gear down indicator.

Original NASA ASRS Text

Title: COMMUTER HAS NO GREEN LIGHT FOR L MAIN GEAR WHEN GEAR EXTENDED.

Narrative: THE GEAR WAS LOWERED AND THE L MAIN GREEN LIGHT REMAINED OUT. PERMISSION FOR A LOW PASS OVER RWY 33R WAS GIVEN AND THE TWR RPTED ALL 3 GEAR APPEARED DOWN AND LOCKED. CAUTION/APU LIGHTS TEST SHOWED THE LIGHT NOT OPERATING. THE LNDG GEAR INDICATOR MALFUNCTION PROC WAS DONE AND THE ALTERNATE INDICATORS SHOWED 3 GREEN LIGHTS. I BELIEVED THAT THE BULBS WERE BURNED OUT, HOWEVER, I DECLARED AN EMER AND WENT THROUGH THE PRECAUTIONS FOR AN EMER LNDG. EMER EQUIP WAS STANDING BY AS WE MADE A NORMAL LNDG. THE MECHS REPLACED BOTH BULBS IN THE L MAIN GEAR DOWN INDICATOR.

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.