DEV FROM CLRNC RTE -- ALTDEV ALT OVERSHOT -- CP JET GETS OFF RTE AND WHILE THE FLC IS DISCUSSING THIS PROB THEY MISS A XING ALT.

Narrative

WE WERE FLYING FROM CLT TO ROU; FO'S LEG TO FLY. WE FAILED TO COM PROPER PROCS FOR HOW WE WERE GOING TO USE OUR ADVANCED NAV SYS FOR THE SHORT FLT. DURING THE TRIP; IT WAS OBSERVED THAT WE WERE NOT PROCEEDING TO THE INTXN CLRED TO. AT THE SAME TIME WE WERE ISSUED DSCNT INSTRUCTIONS. WITH BOTH THINGS GOING ON AT THE SAME TIME; WE DSNDED BELOW OUR ASSIGNED ALT. BOTH PROBS (NAV AND ALT) WERE CORRECTED; POST-HASTE. WE BOTH DISCUSSED THIS THOROUGHLY WITH EACH OTHER AND FELT THERE WERE 2 MAJOR ERRORS AND/OR BREAKS IN THE ERROR CHAIN: NOT PROPERLY BRIEFING EACH OTHER BEFORE LEAVING THE RAMP. BOTH PLTS BECAME DISTRACTED WITH A PROB (NAV) AND MOMENTARILY LEFT THE ACFT CTL UNATTENDED WHICH CAUSED THE ALT PROB. WE BOTH FEEL FORTUNATE WE WERE ABLE TO RECOGNIZE AND BREAK THIS CHAIN OF ERRORS BEFORE ANYTHING WORSE HAPPENED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: THE RPTR SAID THAT THE FO WAS FAIRLY NEW TO THE CITATION III 650 WITH FMC AND THE FO SET UP THE FMC TO TRACK THE RTE; BUT HE INTENDED TO FLY USING THE VHF NAV ONLY. THE CAPT WAS AWARE THAT THE FO WAS DOING SOMETHING NON- STANDARD; BUT DUE TO THE PRESS OF OTHER DUTIES HE DID NOT GET A BRIEFING. THE CAPT SAID THAT HE KNEW THAT HE SHOULD HAVE RESOLVED THE QUESTIONS WHILE ON THE GND; BUT THEY WERE TAXIING OUT AT THE TIME AND HE DID NOT WANT TO MISS HIS DEP SLOT SO HE PRESSED ON. THE FIRST PROB THAT THE CAPT NOTICED WAS THAT THEY WERE OFF RTE DURING THE BUZZY 5 ARR. THE CAPT SAID THAT HE AND THE FO DISCUSSED THE SERIES OF EVENTS EXTENSIVELY OVER THE NEXT 2 DAYS AND THEY WERE BOTH SATISFIED THAT THE LESSONS WERE WELL LEARNED. THERE HAS BEEN NO CONTACT FROM THE FAA TO DATE.