Narrative:

After departure and gear retraction; the in-transit light remained illuminated and the hydraulic pump continued to run. We ran the QRH; notified ATC; and returned to ZZZ. We requested crash fire rescue equipment and an emergency was declared by the ATC controller and an uneventful normal landing was completed. Upon reaching the gate on the postflt; the landing gear were discovered to be thickly coated with ice/slush. There was a thin layer of slush on the runway and txwys. No limitations were exceeded while departing. A brasilia landed ahead of us and took off just prior to us without any issues. There was a thin layer of slush on the runway and txwys. Perhaps better snow removal would have prevented the landing gear retraction malfunction. The actual conditions did not accurately match the field conditions in the NOTAMS. Runway was reported as clear and dry and it was at least 50% covered with less than 1/2 inch snow/slush. The runway was in much better shape for our second departure later. I personally went out and inspected the runway before our second departure.

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Original NASA ASRS Text

Title: SF340 CREW REPORTS THE FAILURE OF THEIR LANDING GEAR TO RETRACT AFTER TKOF IN FREEZING CONDITIONS.

Narrative: AFTER DEP AND GEAR RETRACTION; THE IN-TRANSIT LIGHT REMAINED ILLUMINATED AND THE HYD PUMP CONTINUED TO RUN. WE RAN THE QRH; NOTIFIED ATC; AND RETURNED TO ZZZ. WE REQUESTED CFR AND AN EMER WAS DECLARED BY THE ATC CTLR AND AN UNEVENTFUL NORMAL LNDG WAS COMPLETED. UPON REACHING THE GATE ON THE POSTFLT; THE LNDG GEAR WERE DISCOVERED TO BE THICKLY COATED WITH ICE/SLUSH. THERE WAS A THIN LAYER OF SLUSH ON THE RWY AND TXWYS. NO LIMITATIONS WERE EXCEEDED WHILE DEPARTING. A BRASILIA LANDED AHEAD OF US AND TOOK OFF JUST PRIOR TO US WITHOUT ANY ISSUES. THERE WAS A THIN LAYER OF SLUSH ON THE RWY AND TXWYS. PERHAPS BETTER SNOW REMOVAL WOULD HAVE PREVENTED THE LNDG GEAR RETRACTION MALFUNCTION. THE ACTUAL CONDITIONS DID NOT ACCURATELY MATCH THE FIELD CONDITIONS IN THE NOTAMS. RWY WAS RPTED AS CLR AND DRY AND IT WAS AT LEAST 50% COVERED WITH LESS THAN 1/2 INCH SNOW/SLUSH. THE RWY WAS IN MUCH BETTER SHAPE FOR OUR SECOND DEP LATER. I PERSONALLY WENT OUT AND INSPECTED THE RWY BEFORE OUR SECOND DEP.

Data retrieved from NASA's ASRS site as of January 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.