A crj-200 captain reported receiving a gear disagree warning message when the left main gear failed ...

Narrative:

We took off and upon gear retraction received a gear disagree master warning message. We leveled off at 6;000 ft and identified the problem that the left main gear wouldn't retract which produced the gear disagree message. We then followed all QRH procedures which required manually extending the landing gear. After completing the QRH; we decided it would be in our best interest to return to [departure airport] and declare an emergency as a precaution even though we had a 3 green indication for the gear. The landing was uneventful and we returned back to the gate safely.

Original NASA ASRS Text

Title: A CRJ-200 Captain reported receiving a GEAR DISAGREE warning message when the left main gear failed to retract. They ran the procedure; manually extended the gear; declared an emergency; and returned to departure airport.

Narrative: We took off and upon gear retraction received a Gear Disagree Master Warning MSG. We leveled off at 6;000 FT and identified the problem that the left main gear wouldn't retract which produced the Gear Disagree message. We then followed all QRH procedures which required manually extending the landing gear. After completing the QRH; we decided it would be in our best interest to return to [departure airport] and declare an emergency as a precaution even though we had a 3 green indication for the gear. The landing was uneventful and we returned back to the gate safely.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	978185
Time
Date	201111
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	Regional Jet 200 ER/LR (CRJ200)
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Component
Aircraft Component	Main Gear
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical

A crj-200 captain reported receiving a gear disagree warning message when the left main gear failed to retract. They ran the procedure; manually extended the gear; declared an emergency; and returned to departure airport.