Narrative:

This occurred during my 5TH leg of the day flying this airplane and there were no indications; that I noticed; on the previous 4 legs that it would fail. Cleared by ZZZ tower to land; first officer requested gear down; flaps 30 degrees before landing check. I selected gear down and shortly thereafter we received a gear disagreement warning EICAS message. Once idented I told tower we were going to have to cancel the landing clearance and get a vector to address a gear issue. They instructed us to turn to 270 degrees and climb to 4000 ft; contact departure and let them know the nature of the situation. We complied. I notified the flight attendant of our issue and told her to standby and I would get back to her. Instructed the first officer that he had the controls and radios and began working the QRH. Per the QRH we maintained less than 200 KTS and I switched the 2 and 3B hydraulic pumps on; waited at least 30 seconds and the message persisted. I then cycled the landing gear twice; starting the clock during each up and down selection; waited at least 30 seconds but the message returned during each down selection. While monitoring the fuel; I decided 2 attempts of the multiple attempts allowed by the QRH were enough and it was time to manually deploy the gear and did so. It seemed like an eternity but manually deploying the gear gave us a 3 green indication and I would like to add a tremendous feeling of relief. I completed the QRH; notified ATC that I was declaring an emergency and to roll the trucks. I was thinking a fly-by would be appropriate and before I requested it tower offered it as a suggestion. I said it sounded good to me. I notified the flight attendant of our intentions; and told her that I wanted her to tell the passenger once we did the fly-by that all indications are that we will have a landing without incident but just as a precautionary measure I would like them to brace on landing. I was confident the gear was down but I was skeptical as to how down they were and wanted them to brace in the event of collapse on landing. I assumed PF duties. During the fly-by; tower and another jet confirmed the gear appeared to be down. We then made a right traffic pattern and landed without incident; canceled the emergency and taxied to the gate. Coincidentally there was a dash 8 on the ramp that had evacuate/evacuationed also in an emergency situation. It was afternoon and appeared to have plenty of resources (equipment and personnel) to address both situations; very nice. Mechanical failure of the main gear selection valve; according to my conversation with the mechanic 2 days later.

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Original NASA ASRS Text

Title: A CRJ200 MAIN LNDG SELECTOR VALVE FAILED. AN EMER WAS DECLARED; THE LNDG GEAR WERE EXTENDED MANUALLY; AND THE ACFT LANDED NORMALLY.

Narrative: THIS OCCURRED DURING MY 5TH LEG OF THE DAY FLYING THIS AIRPLANE AND THERE WERE NO INDICATIONS; THAT I NOTICED; ON THE PREVIOUS 4 LEGS THAT IT WOULD FAIL. CLRED BY ZZZ TWR TO LAND; FO REQUESTED GEAR DOWN; FLAPS 30 DEGS BEFORE LNDG CHK. I SELECTED GEAR DOWN AND SHORTLY THEREAFTER WE RECEIVED A GEAR DISAGREEMENT WARNING EICAS MESSAGE. ONCE IDENTED I TOLD TWR WE WERE GOING TO HAVE TO CANCEL THE LNDG CLRNC AND GET A VECTOR TO ADDRESS A GEAR ISSUE. THEY INSTRUCTED US TO TURN TO 270 DEGS AND CLB TO 4000 FT; CONTACT DEP AND LET THEM KNOW THE NATURE OF THE SITUATION. WE COMPLIED. I NOTIFIED THE FLT ATTENDANT OF OUR ISSUE AND TOLD HER TO STANDBY AND I WOULD GET BACK TO HER. INSTRUCTED THE FO THAT HE HAD THE CTLS AND RADIOS AND BEGAN WORKING THE QRH. PER THE QRH WE MAINTAINED LESS THAN 200 KTS AND I SWITCHED THE 2 AND 3B HYD PUMPS ON; WAITED AT LEAST 30 SECONDS AND THE MESSAGE PERSISTED. I THEN CYCLED THE LNDG GEAR TWICE; STARTING THE CLOCK DURING EACH UP AND DOWN SELECTION; WAITED AT LEAST 30 SECONDS BUT THE MESSAGE RETURNED DURING EACH DOWN SELECTION. WHILE MONITORING THE FUEL; I DECIDED 2 ATTEMPTS OF THE MULTIPLE ATTEMPTS ALLOWED BY THE QRH WERE ENOUGH AND IT WAS TIME TO MANUALLY DEPLOY THE GEAR AND DID SO. IT SEEMED LIKE AN ETERNITY BUT MANUALLY DEPLOYING THE GEAR GAVE US A 3 GREEN INDICATION AND I WOULD LIKE TO ADD A TREMENDOUS FEELING OF RELIEF. I COMPLETED THE QRH; NOTIFIED ATC THAT I WAS DECLARING AN EMER AND TO ROLL THE TRUCKS. I WAS THINKING A FLY-BY WOULD BE APPROPRIATE AND BEFORE I REQUESTED IT TWR OFFERED IT AS A SUGGESTION. I SAID IT SOUNDED GOOD TO ME. I NOTIFIED THE FLT ATTENDANT OF OUR INTENTIONS; AND TOLD HER THAT I WANTED HER TO TELL THE PAX ONCE WE DID THE FLY-BY THAT ALL INDICATIONS ARE THAT WE WILL HAVE A LNDG WITHOUT INCIDENT BUT JUST AS A PRECAUTIONARY MEASURE I WOULD LIKE THEM TO BRACE ON LNDG. I WAS CONFIDENT THE GEAR WAS DOWN BUT I WAS SKEPTICAL AS TO HOW DOWN THEY WERE AND WANTED THEM TO BRACE IN THE EVENT OF COLLAPSE ON LNDG. I ASSUMED PF DUTIES. DURING THE FLY-BY; TWR AND ANOTHER JET CONFIRMED THE GEAR APPEARED TO BE DOWN. WE THEN MADE A R TFC PATTERN AND LANDED WITHOUT INCIDENT; CANCELED THE EMER AND TAXIED TO THE GATE. COINCIDENTALLY THERE WAS A DASH 8 ON THE RAMP THAT HAD EVACED ALSO IN AN EMER SITUATION. IT WAS AFTERNOON AND APPEARED TO HAVE PLENTY OF RESOURCES (EQUIP AND PERSONNEL) TO ADDRESS BOTH SITUATIONS; VERY NICE. MECHANICAL FAILURE OF THE MAIN GEAR SELECTION VALVE; ACCORDING TO MY CONVERSATION WITH THE MECH 2 DAYS LATER.

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.