A 'carj' crew, on final to cvg, received an 'unsafe gear' indication upon lowering the gear.

Attributes
ACN	531191
Time
Date	200111
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : cvg.airport
State Reference	OH
Altitude	msl single value : 2200
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : cvg.tracon tower : cvg.tower
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	approach : visual arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : multi engine
Experience	flight time last 90 days : 130 flight time total : 3500 flight time type : 900
ASRS Report	531191
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : gear unsafe/disagree warning other flight crewa other flight crewb
Resolutory Action	aircraft : equipment problem dissipated controller : provided flight assist flight crew : executed go around flight crew : declared emergency
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

On nov/fri/01, at XA00 local while making approach to cincinnati northern kentucky airport in air carrier flight XXXX had unsafe gear indication on final to runway 18L. Captain at controls. Had been switched to cincinnati tower from approach and cleared to land. Captain at controls flying assigned speed of 170 KIAS called for gear down and flaps to 30 degrees. Received unsafe gear indication, main gear both green down and locked and nose gear unsafe gear disagree warning. Per protocol captain took radios and instructed me to proceed with QRH procedures. Tower notified of problem and go around commenced. During go around climb the gear disagree warning ceased and nose gear now indicated green down and locked. All gear indications were green down and locked and we decided to leave the gear down to preclude any further problems with the gear. We proceeded with all our checklist and procedures and decided to confer with maintenance. Even though all gear indications were good and warning was gone we wanted to get their opinion before attempting to land. We were in contact with approach at this time informed them of our status and intentions. The flight attendant and passenger were also notified. After consulting with maintenance they informed us that they would like us to complete a low approach and tower fly-by to visually check gear. Passenger and flight attendant were again notified of our intent. We coordinated with approach/tower to complete fly-by. An emergency was declared. We performed low approach to runway 18R and both tower and crash fire rescue equipment truck crew verified gear appeared down and locked. We decided it was safe to land and received vectors from ATC back around to runway 18R for a visual approach. All checklists and procedures were completed and a landing was completed to runway 18R without further incident.

Original NASA ASRS Text

Title: A 'CARJ' CREW, ON FINAL TO CVG, RECEIVED AN 'UNSAFE GEAR' INDICATION UPON LOWERING THE GEAR.

Narrative: ON NOV/FRI/01, AT XA00 LCL WHILE MAKING APCH TO CINCINNATI NORTHERN KENTUCKY ARPT IN ACR FLT XXXX HAD UNSAFE GEAR INDICATION ON FINAL TO RWY 18L. CAPT AT CTLS. HAD BEEN SWITCHED TO CINCINNATI TWR FROM APCH AND CLRED TO LAND. CAPT AT CTLS FLYING ASSIGNED SPD OF 170 KIAS CALLED FOR GEAR DOWN AND FLAPS TO 30 DEGS. RECEIVED UNSAFE GEAR INDICATION, MAIN GEAR BOTH GREEN DOWN AND LOCKED AND NOSE GEAR UNSAFE GEAR DISAGREE WARNING. PER PROTOCOL CAPT TOOK RADIOS AND INSTRUCTED ME TO PROCEED WITH QRH PROCS. TWR NOTIFIED OF PROB AND GAR COMMENCED. DURING GAR CLB THE GEAR DISAGREE WARNING CEASED AND NOSE GEAR NOW INDICATED GREEN DOWN AND LOCKED. ALL GEAR INDICATIONS WERE GREEN DOWN AND LOCKED AND WE DECIDED TO LEAVE THE GEAR DOWN TO PRECLUDE ANY FURTHER PROBS WITH THE GEAR. WE PROCEEDED WITH ALL OUR CHKLIST AND PROCS AND DECIDED TO CONFER WITH MAINT. EVEN THOUGH ALL GEAR INDICATIONS WERE GOOD AND WARNING WAS GONE WE WANTED TO GET THEIR OPINION BEFORE ATTEMPTING TO LAND. WE WERE IN CONTACT WITH APCH AT THIS TIME INFORMED THEM OF OUR STATUS AND INTENTIONS. THE FLT ATTENDANT AND PAX WERE ALSO NOTIFIED. AFTER CONSULTING WITH MAINT THEY INFORMED US THAT THEY WOULD LIKE US TO COMPLETE A LOW APCH AND TWR FLY-BY TO VISUALLY CHK GEAR. PAX AND FLT ATTENDANT WERE AGAIN NOTIFIED OF OUR INTENT. WE COORDINATED WITH APCH/TWR TO COMPLETE FLY-BY. AN EMER WAS DECLARED. WE PERFORMED LOW APCH TO RWY 18R AND BOTH TWR AND CFR TRUCK CREW VERIFIED GEAR APPEARED DOWN AND LOCKED. WE DECIDED IT WAS SAFE TO LAND AND RECEIVED VECTORS FROM ATC BACK AROUND TO RWY 18R FOR A VISUAL APCH. ALL CHKLISTS AND PROCS WERE COMPLETED AND A LNDG WAS COMPLETED TO RWY 18R WITHOUT FURTHER INCIDENT.

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.