DCH8-200 RETURNS TO PHX; AZ; WHEN LNDG GEAR WOULD NOT RETRACT AFTER TKOF. ALTERNATE GEAR RELEASE DOOR WAS LEFT OPEN PREVENTING NORMAL OP.

Narrative

THIS FLT WAS THE START OF OUR SHIFT. THE FO DID THE WALKAROUND PREFLT AND I DID THE ACCEPTANCE CHK IN THE COCKPIT. EVERYTHING WAS NORMAL UNTIL AFTER TKOF. THE FO WAS THE PF. AFTER THE 'GEAR UP' CALL WAS MADE BY THE FO AS THE PF; I RAISED THE GEAR HANDLE; NOTHING HAPPENED. I CYCLED THE GEAR HANDLE A FEW TIMES AND THE GEAR STILL DID NOT RETRACT. WE COMPLETED ALL OUR CHKLISTS FOR OUR RETURN TO PHX AND I STARTED TO LOOK AROUND IN THE COCKPIT FOR CLUES TO OUR PROB. MY FO SWORE THAT HE HAD CHKED THAT THE GEAR PINS WERE REMOVED AND STORED IN THEIR COMPARTMENT IN THE AIRSTAIR DOOR; HE CHKED THAT DURING THE WALKAROUND. AT THIS TIME I LOOKED AT THE OVERHEAD PANEL AND NOTICED THE ALTERNATE RELEASE DOOR AJAR; I THEN PROCEEDED TO PUSH THE DOOR SHUT. NOW WE LOOKED AT EACH OTHER LIKE WE KNEW WHAT THE PROB WAS. I SELECTED GEAR UP WITH THE GEAR HANDLE AND THE GEAR RETRACTED NORMALLY. THEN I SELECTED GEAR DOWN AND THE GEAR EXTENDED NORMALLY. WE ELECTED TO RETURN TO PHX BECAUSE OUR REMAINING FUEL NOW BEING BELOW MINIMUM FUEL REQUIRED FOR COMPLETION OF THE FLT ACCORDING TO OUR RELEASE. A CHK OF THE GEAR ASSEMBLY AND THE WHEEL WELL WAS MADE. NO HYD LEAKS OR ANY OTHER DEFICIENCIES WERE FOUND AND HYD QUANTITIES IN THE WHEEL WELL READ NORMAL LEVELS. WE DEPARTED ON OUR FLT AGAIN AND GEAR RETRACTED NORMALLY; THE FLT WAS COMPLETED WITHOUT ANY INCIDENTS. IN CONCLUSION; I WAS NOT AWARE I HAD TO WRITE UP ANYTHING SINCE WE HAD FOUND THE GEAR TO CYCLE CORRECTLY IN THE AIR AFTER CLOSING THE ALTERNATE RELEASE DOOR BEFORE LNDG. FURTHER THE MECH FOUND NOTHING WRONG DURING THEIR INVESTIGATION ON THE GND. LESSON LEARNED FROM THIS IS TO BE MORE DILIGENT WITH THE ACCEPTANCE CHKLIST AND PUT YOUR HAND ON THE ALTERNATE RELEASE DOOR EVERY TIME. ANOTHER LESSON LEARNED IS TO WRITE UP ANY PERCEIVED MECHANICAL DIFFICULTIES EVEN IF ALL SYS SEEM TO BE WORKING AND HAVE A MECH SIGN OFF THE RELEASE IF THERE IS ANY DOUBT AS TO A MECHANICAL IRREGULARITY. HOW WE CAN PREVENT THIS FROM HAPPENING IN THE FUTURE; IS IN OUR INITIAL AND RECURRENT TRAINING EMPHASIZING THE CLOSURE OF THE ALTERNATE RELEASE DOOR. ALSO A PROC IN THE ABNORMAL SECTION OF THE CFM FOR FAILURE OF GEAR TO RETRACT WOULD BE HELPFUL TO ALL PLTS.