ALT OVERSHOT ON CLIMBOUT. NO CONFLICT.

Narrative

WE DEPARTED MDW IN A SMT MY COPLT WAS EXPERIENCING DIFFICULTY WITH HIS HEAD SET; SO I TOOK THE CLRNC WHICH INCLUDED CLIMB AND MAINTAIN 3000'. WE MADE A ROUTINE TKOF AND MY COPLT RETURNED TO THE TASK OF FIXING HIS HEADSET. AT ABOUT 2000 TO 2500' HE APPEARED TO HAVE IT WORKING SO HE CONTINUED ON TO THE AFTER TKOF CHECKLIST. AS WE WERE FINISHING THE LAST ITEM; DEP CTL CAME UP ON THE RADIO AND ASKED 'WHERE ARE WE GOING?' I LOOKED AT THE ALT AND WE WERE PASSING 3600'. FORTUNATELY THERE WAS NO CONFLICTING TFC AND DEP CLRED US TO MAINTAIN 4000'. I BELIEVE THERE WERE SEVERAL FACTORS THAT CONTRIBUTED TO THIS POTENTIALLY DANGEROUS SITUATION. FIRST; THE COPLT AND I HAD ONLY FLOWN TOGETHER ONCE BEFORE AND I ALLOWED HIM TO DISTRACT ME FROM MY DUTIES. THE FACT THAT HE WAS NOT PAYING ATTN TO THE OUTSIDE OF THE ACFT IN THIS HIGH TFC ENVIRONMENT ANGERED ME AND I SHIFTED MY SCAN TO THE OUTSIDE MUCH LONGER THAN I SHOULD HAVE. SECOND; THE COMPANY ALSO OPERATES SEVERAL LTT WHICH HAVE AURAL ALT WARNING. THE MAJORITY OF MY TIME IS SPENT IN THIS ACFT. PERHAPS BEING ACCUSTOMED AND DEPENDENT ON THE AURAL SYSTEM CAUSED ME TO BE A LITTLE COMPLACENT WITH MY HABIT PATTERNS CONCERNING ALT CTL AND MONITORING. FINALLY; THE COMPANY HAS A POLICY OF BOTH PLTS CALLING 1000' AND 200 PRIOR TO LEVEL OFF. I HAVE NO IDEA HOW WE BOTH MISSED 2 SEPARATE CALL OUTS; BUT I AM FAIRLY CERTAIN THAT WHEN WE FLY TOGETHER AGAIN WE WILL NOT MISS ANY ALT CALL OUTS.