ALTDEV ALT OVERSHOT IN CLB. CLRNC INTERP.

Narrative

WHILE CLBING ENRTE; USING AUTOPLT COUPLED TO INS; THE COPLT WENT OFF FREQ TO TALK WITH BASE OPS. DURING THIS PERIOD A NEW ALT WAS ASSIGNED. THOUGH I READ BACK AN ALT TO THE CTLR I DID NOT REMEMBER TO SET THE ALT ALERTER. WHEN THE COPLT RETURNED HE NOTED THE PROB AND ASKED ME WHAT SHOULD BE SET IN THE ALERTER. I SAID THAT I THOUGHT WE WERE ISSUED FL340; BUT THAT DIDN'T SOUND RIGHT AS A FLT LEVEL AND BESIDES WE WERE ONLY FILED FOR FL310. HOWEVER; HE HAD ALREADY SET FL340 AND BY THE TIME WE TALKED THROUGH THE PROB WE HAD ALREADY PASSED FL310 AND THE CTLR CAUGHT THE ERROR AT FL320. WE RETURNED TO FL310. WE WERE TOLD OF NO CONFLICT WITH OTHER TFC. I'VE ATTENDED A NUMBER OF COCKPIT RESOURCE MGMNT COURSES AND I GUESS THIS IS A CLASSIC EXAMPLE OF HOW IMPORTANT IT IS FOR BOTH PLTS TO CONFIRM CLRNCS IMMEDIATELY WHEN THEY ARE RECEIVED. IF YOU WAIT TOO LONG THERE ARE JUST TOO MANY THINGS GOING ON THAT MAY CONFUSE THE ISSUE. WE HAVE INSTITUTED A POLICY WHEREBY AFTER THE PNF READS BACK AN ALT CLRNC TO ATC; HE SETS IT IN THE ALERTER AND THE PF IMMEDIATELY CONFIRMS VERBALLY. EVEN GREATER CARE MUST BE TAKEN WHEN THE RADIOS ARE BEING USED FOR 2 DIFFERENT FREQS.