WDB ON DSCNT MISSED XING RESTR. LOSS OF SEPARATION.

Narrative

I WAS ON THE FIRST LEG OF MY IOE (INITIAL OP EXPERIENCE) ON A WDB. (MY FIRST FLT OF THE ACFT.) THE FLT WAS LAX/ATL. AS WE BEGAN THE ROME ARR; ATC ASKED US TO CROSS 50 NW OF ROME AT FL290; DSND TO FL240. I TRIED UNSUCCESSFULLY TO ENTER THE RESTRICTION IN THE FMS. AFTER 3 ATTEMPTS; THE CAPT TRIED UNSUCCESSFULLY AND TRIED TO EXPLAIN WHY IT WOULDN'T TAKE IT. MEANWHILE; NO DSCNT WAS STARTED. CAPT SAID 'JUST DSND MANUALLY; I'M GOING FOR THE ATIS.' HOWEVER I DSNDED; IT WASN'T FAST ENOUGH; ESPECIALLY WITH A 70 KT TAILWIND. AS WE NEARED THE 50 NW POINT FROM ROME; THE CTL BECAME MORE CONCERNED AND ASKED IF WE UNDERSTOOD THE CLRNC; AND WHAT OUR DME WAS. I SAID WE UNDERSTOOD; BUT DIDN'T REPLY REGARDING TO DME BECAUSE I WASN'T SURE WHAT HE MEANT; FROM WHERE. AS I WAS CALCULATING DISTANCES; HE CAME BACK AND ASKED IF WE COULD BE OUT OF FL290 IN 30 SECONDS. WE WERE JUST UNDER FL310 AT THE TIME AND I SAID YES. WE MADE IT; CONTINUING DOWN TO FL240. WE HAD THE CONFLICT ACFT IN SIGHT FOR ABOUT 43 SECONDS TO A MIN; AS WE WENT BY 1500 FT - 2000 FT ABOVE US AT ABOUT 11 - 1 O'CLOCK. THE CAPT WAS BACK IN THE LOOP AT ABOUT THE '30 SECOND' REQUEST; AND CAPT ALSO SET FL240 IN THE MCP; AS THAT WAS MISSED WHEN THE CLRNC WAS FIRST RECEIVED. IT IS VERY CLEAR TO ME WHAT THE PROB WAS HERE. A BIG PART OF IT WAS MY FIRST LEG FLYING THE AIRPLANE; BUT ALSO; WE ARE FLYING AN AIRPLANE; NOT A COMPUTER. MY FOCUS ON THE FMS GOT IN THE WAY OF MY DOING A VERY SIMPLE ACFT DSCNT PROFILE. I WILL BE FOCUSING ON FLYING FIRST; PROGRAMMING SECOND. SUPPLEMENTAL INFO FROM ACN 259900: WHEN I DIVERTED MY ATTN TO GETTING THE ATIS WE HAD APPROX 30 MI TO GO TO THE XING FIX AND TO LOSE 6000 FT THIS WAS NOT A PROB. HOWEVER; A VERY SLOW DSCNT OCCURRED DUE TO THE FO'S UNFAMILIARITY WITH THE DSCNT FEATURES IN THE FMS ONE PROB HERE IS THE TRAINING IN GND SCHOOL AND THE SIMULATOR DOESN'T ALWAYS GIVE A PLT A GOOD KNOWLEDGE OF DSCNT FEATURES OF THE FMS DUE TO THE FACT THAT MOST OF THE SIMULATOR WORK IS PATTERN ALTS. TO THE EXTENT POSSIBLE; THIS CHK AIRMAN FROM NOW ON FORWARD WILL NOT ASSUME THAT THE NEW PLT WILL YET HAVE A GOOD OPERATING KNOWLEDGE OF THE EQUIP AND WHEN THOSE TIMES THAT REQUIRE DIVERSION OF ATTN TO OTHER DUTIES TO KEEP A CLOSER EYE ON THE ACFT.