B737-300 RETURNS TO DEP ARPT WHEN R MAIN GEAR FAILS TO RETRACT.

Narrative

RETURNED TO DEP ARPT DUE TO R MAIN LNDG GEAR NOT RETRACTING AFTER TKOF. THE R GEAR RED INDICATOR LIGHT ILLUMINATED AFTER THE GEAR HANDLE WAS IN THE 'UP' POS. I LOWERED THE GEAR AND GOT 3 GREEN LIGHTS INDICATING THAT ALL 3 LNDG GEAR WERE DOWN AND LOCKED. I THEN RETRACTED THE LNDG GEAR AND GOT THE SAME INDICATION; R GEAR RED LIGHT ILLUMINATED. IN POSITIONING THE GEAR HANDLE IN THE 'OFF' POS THE RED AS WELL AS THE GREEN GEAR LIGHT ILLUMINATED. WE DISCONNECTED THE AUTOPLT AND THE ACFT HAD A SLIGHT YAW. I INFORMED DEP CTL THAT MY R GEAR WOULD NOT COME UP AND THAT I WAS RETURNING FOR A FLY-BY IN ORDER TO CONFIRM THE PROB. I CALLED MAINT AND INFORMED THEM OF WHAT WAS HAPPENING AND OF WHAT I WAS GOING TO DO. I INFORMED MY CREW AND PAX OF THE GEAR PROB AND ALSO OF THE FLY-BY; AND SURE ENOUGH IT WAS CONFIRMED BY ATC THAT THE R GEAR WAS DOWN; WHILE THE L AND NOSE GEAR WERE UP. THE GEAR HANDLE WAS IN THE OFF POS. I DECLARED AN EMER. I TALKED TO MY CREW AND PAX; WE THEN BROUGHT THE GEAR HANDLE DOWN AND GOT 3 GREEN LIGHTS DOWN AND LOCK; HYD PRESSURE AND QUANTITY NORMAL. I THEN TALKED TO MY CREW AND PAX AND TOLD THEM THAT THE LNDG GEAR WAS DOWN AND THAT WE WERE RETURNING TO THE ARPT AND THAT THE LNDG WOULD BE NORMAL; BUT IF THEY SAW EMER EQUIP NOT TO WORRY FOR THEY WOULD BE THERE FOR OUR SAFETY. ALL CHKLISTS WERE COMPLETED AND A NORMAL APCH AND LNDG WAS ACCOMPLISHED.