Unsafe gear indication results in go around.

Attributes
ACN	259315
Time
Date	199312
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : pwm
State Reference	ME
Altitude	msl bound lower : 2000 msl bound upper : 2000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : pwm
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : commercial pilot : flight engineer pilot : atp pilot : instrument
Experience	flight time last 90 days : 200 flight time total : 9000 flight time type : 2000
ASRS Report	259315
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

On ground to pwm we selected gear down, nothing happened. We recycled the gear down, again nothing. Leaving the handle in the down position, we initiated a go around and pulled out the quick reference handbook. After reviewing what we would do, we started the checklist. The inhibit switch cover was moved and down the gear came normally to our surprise. We reviewed the rest of the checklist, but finding the gear down normally with gear doors closed and all green lights, we elected not to finish the checklist verbatim as this would, I felt, not accomplish anything else. The gear was down. We landed uneventfully not declaring an emergency. Upon mechanical investigation it was determined that the inhibit switch had some screws that were loose. They were subsequently tightened and a signoff was completed after we test flew the aircraft in a maintenance acceptance flight.

Original NASA ASRS Text

Title: UNSAFE GEAR INDICATION RESULTS IN GAR.

Narrative: ON GND TO PWM WE SELECTED GEAR DOWN, NOTHING HAPPENED. WE RECYCLED THE GEAR DOWN, AGAIN NOTHING. LEAVING THE HANDLE IN THE DOWN POS, WE INITIATED A GAR AND PULLED OUT THE QUICK REF HANDBOOK. AFTER REVIEWING WHAT WE WOULD DO, WE STARTED THE CHKLIST. THE INHIBIT SWITCH COVER WAS MOVED AND DOWN THE GEAR CAME NORMALLY TO OUR SURPRISE. WE REVIEWED THE REST OF THE CHKLIST, BUT FINDING THE GEAR DOWN NORMALLY WITH GEAR DOORS CLOSED AND ALL GREEN LIGHTS, WE ELECTED NOT TO FINISH THE CHKLIST VERBATIM AS THIS WOULD, I FELT, NOT ACCOMPLISH ANYTHING ELSE. THE GEAR WAS DOWN. WE LANDED UNEVENTFULLY NOT DECLARING AN EMER. UPON MECHANICAL INVESTIGATION IT WAS DETERMINED THAT THE INHIBIT SWITCH HAD SOME SCREWS THAT WERE LOOSE. THEY WERE SUBSEQUENTLY TIGHTENED AND A SIGNOFF WAS COMPLETED AFTER WE TEST FLEW THE ACFT IN A MAINT ACCEPTANCE FLT.

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.