COMMUTER ACFT HAS DOOR HANDLE CAUTION LIGHT ACTIVATE AFTER TKOF.

Narrative

SHORTLY AFTER LIFTOFF; THE CABIN DOOR HANDLE CAUTION LIGHT CAME ON. IN RESPONSE; THE CAPT DECIDED TO RETURN TO OUR DEP BASE FOR LNDG. NO SPECIAL ATC HANDLING WAS REQUIRED; AN EMER WAS NOT DECLARED; AND THE SUBSEQUENT DSCNT AND LNDG WERE UNEVENTFUL. AFTER PARKING AT THE GATE; THE CAPT INSPECTED THE DOOR HANDLE AND DOOR AND VERIFIED THAT THE REQUIRED MECHANICAL INDICES WERE CORRECTLY ALIGNED (DOOR SAFELY SECURED). HE THEN WENT INSIDE TO OPS. THE FLT ATTENDANT AND I REMAINED IN THE ACFT WITH OUR 4 PAX. AFTER ABOUT 15 MINS; THE CAPT RETURNED AND SAID THAT HE HAD DISCUSSED THE SIT WITH MAINT. THEY AGREED THAT IT WAS SAFE TO CONTINUE PROVIDED THAT THE DOOR INDICES WERE VISUALLY VERIFIED TO BE ALIGNED PRIOR TO EVERY DEP. THIS WAS CONSISTENT WITH THE ACFT ABNORMAL PROCS CHKLIST AND THE ACFT MEL. WE THEN DEPARTED; AND ALL SUBSEQUENT FLYING WAS UNEVENTFUL. ENRTE TO OUR NEXT DEST; I PULLED OUT OUR COMPANY OPS MANUAL AND REVIEWED WITH THE CAPT THE SECTION ON IRREGULARITIES. UNSCHEDULED OR PRECAUTIONARY LNDGS REQUIRE IMMEDIATE COORDINATOR NOTIFICATION; IMMEDIATE ATC NOTIFICATION AS APPROPRIATE; A LOGBOOK ENTRY; AND THE CAPT'S WRITTEN STATEMENT. WE HAD DEPARTED WITHOUT MAKING A LOGBOOK ENTRY. IN ADDITION; THE CAPT LATER TOLD ME THAT HE HAD NOT CALLED OUR COMPANY FLT CTL DISPATCH COORDINATOR. I DON'T KNOW; HOWEVER; THAT DISPATCH WASN'T ALREADY 'IN THE LOOP' AS A RESULT OF COM WITH OUR STATION PERSONNEL. THE DEVS COULD HAVE BEEN PREVENTED HAD WE TAKEN MORE TIME TO INSURE THAT REQUIRED DOCUMENTATION AND NOTIFICATION WERE ACCOMPLISHED. AS A FO; I SHOULD HAVE BEEN MORE QUESTIONING WITH REGARD TO COMPLIANCE WITH DIRECTIVES. AT THE TIME WE HAD BEEN ON DUTY FOR MORE THAN 14 HRS.