CL65 FLT CREW HAS THE COCKPIT DOOR OPEN DURING CLBOUT FROM BNA.

Narrative

SHORTLY AFTER PASSING 10000 FT ON CLBOUT THE FLT ATTENDANT CALLED ON THE INTERPHONE; I DO NOT RECALL HER EXACT WORDS BUT WHAT I UNDERSTOOD WERE: 'WE HAVE A SIT HERE; TURN AROUND NOW' AND I RESPONDED 'DO YOU WANT ME TO TURN AROUND AND LAND.' SHE REPLIED 'YES RIGHT AWAY.' I RESPONDED 'OK' AND CLOSED COM WITH THE FLT ATTENDANT. HER TONE OF VOICE EXPRESSED URGENCY. I THOUGHT SHE WAS BEING THREATENED AND THAT SHE COULD NOT SPEAK FREELY. I INSTRUCTED THE FO TO STOP THE CLB AND PREPARE TO RETURN TO BNA FOR A LNDG. THEN I REQUESTED AN ATC CLRNC FOR AN APCH TO NASHVILLE AND REQUESTED THAT POLICE MEET THE ACFT. A CLRNC WAS PROMPTLY ISSUED. WE PREPARED FOR AN OVERWT LNDG. THE FO WAS NEW TO THE COMPANY AND HAS LITTLE EXPERIENCE ON TYPE SO WE DECIDED THAT I SHOULD DO THE LNDG. SHORTLY AFTER WE XFERRED CTL OF THE ACFT THE FLT ATTENDANT CALLED AND ASKED THE FO IF WE WERE LNDG. HE REPLIED 'YES.' I THEN CALLED THE FLT ATTENDANT TO ASK ABOUT HER SIT AND SHE SAID THAT SHE AND THE PAX WERE FINE BUT THAT THE COCKPIT DOOR WAS UNLATCHED AND THAT IT HAD PARTLY OPENED ON TKOF. ONCE IT BECAME CLR THAT NO ACTUAL THREAT EXISTED I XFERRED CTL OF THE ACFT BACK TO THE FO AND REQUESTED CLRNC FROM ATC TO RESUME OUR ORIGINAL FLT PLAN. WE THEN PROCEEDED TO OUR DEST WITHOUT FURTHER INCIDENT. HOW THE PROB AROSE: WHEN THE FLT ATTENDANT CLOSED THE COCKPIT DOOR THE LATCH HANDLE WAS IN THE LOCKED POS. THE LOCKING PIN WAS EXTENDED THUS PREVENTING THE DOOR FROM CLOSING PROPERLY. DURING THE STARTING ENG CHKLIST I CHKED THE DOOR AND ERRONEOUSLY THOUGHT THAT THE DOOR WAS PROPERLY CLOSED AND LOCKED. IT WAS NOT; EVEN THOUGH IT APPEARED TO BE. THE LATCHING HANDLE WAS IN THE LOCKED POS. CONTRIBUTING FACTOR: WHEN THE FLT ATTENDANT CALLED THE COCKPIT TO RPT THE PROB HER CHOICE OF WORDS CAUSED ME TO THINK THAT A SECURITY THREAT EXISTED AND THAT A LNDG AT THE NEAREST SUITABLE ARPT WAS REQUIRED. HOW IT WAS DISCOVERED: THE PROB OF OUR MISCOM WAS DISCOVERED WHEN I FINALLY ASKED THE FLT ATTENDANT ABOUT HER CONDITION. BY THEN I HAD DSNDED 7000 FT AND WAS ENTERING BASE LEG TO RWY 2L AT BNA. THE WHOLE THING COULD HAVE BEEN AVOIDED HAD I ASKED THE FLT ATTENDANT THE SAME QUESTION ON HER INITIAL CALL. CORRECTIVE ACTIONS: WHEN A PROB IS DISCOVERED IT MUST BE COMMUNICATED TO THE OTHER CREW MEMBERS IN CLR AND CONCISE LANGUAGE OTHERWISE MISUNDERSTANDINGS WILL OCCUR. ALSO WHEN A PROB IS FIRST RAISED THE CREW MEMBERS BEING APPRAISED NEED TO ASK ENOUGH QUESTIONS TO INSURE THAT AN ACCURATE PICTURE OF THE SIT IS CLRLY ESTABLISHED. TRAINING OF THE FLT ATTENDANTS NEEDS TO EMPHASIZE THE REQUIREMENT TO VERIFY THAT THE LATCHING HANDLE IS IN THE UNLOCKED POS PRIOR TO CLOSING THE COCKPIT DOOR. THIS WAY NO DAMAGE WILL OCCUR TO THE LATCHING PIN AND IT WILL BE POSSIBLE TO PROPERLY LOCK THE DOOR. ONE LAST POINT IN DISCUSSING THIS SIT WITH THE FLT ATTENDANT AFTER THE FLT SHE DID MENTION THAT CONVERSATION WITH THE COCKPIT WAS DIFFICULT TO UNDERSTAND BECAUSE OF POOR INTERPHONE PERFORMANCE.