MD80 FLT CREW UNDERSHOOTS THE ASSIGNED XING ALT ON TRAKE ARR.

Narrative

LOCATION: KAYLA ARC ON TRAKE 8 ARR. XING RESTR OF 15000 FT AT THE KAYLA ARC WAS RECEIVED. WE DISCUSSED THE KAYLA ARC FIX AS WE WERE CLRED TO FTZ DIRECT. WE BOTH UNDERSTOOD THE CLRNC TO CROSS THE ARC AT 15000 FT. CORRECTION; THE CLRNC WAS 11000 FT AT THE KAYLA ARC. WE BOTH UNDERSTOOD THE CLRNC TO CROSS THE ARC AT 11000 FT. AS WE NEARED THE FIX; I (THE CAPT) HAD FTZ TUNED ON MY SIDE AND THE DME AND REMINDED THE FO OF THE RESTR. HE ACKNOWLEDGED. AS WE GOT CLOSER AGAIN; I TOLD THE FO OF THE ALT AND THE DISTANCE TO GO. HE ACKNOWLEDGED AND BEGAN TO INCREASE THE RATE OF DSCNT. AT THIS TIME WE WERE GIVEN A FREQ CHANGE. MY XMIT BUTTON WAS NOT SELECTED TO CALL OUT ON THE FREQ SO THE CTR COULDN'T HAVE HEARD ME SAY GOOD-BYE. WHEN I CHKED IN ON THE NEW FREQ AND APCH DID NOT ANSWER; I WENT TO THE OLD FREQ AND HE DID NOT ANSWER. I THEN NOTICED MY XMITTER WAS NOT SELECTED. THE FLT ATTENDANTS HAD CALLED RIGHT BEFORE THIS AND MY XMITTER WAS STILL IN THE CABIN INTERCOM TALK POS. IT WAS MY INTENTION TO ADVISE THE NEW CTLR WE MAY BE HIGH AT THE ARC XING RESTR BUT WITH THE FREQ CHANGE AND XMITTER SELECTION ERROR; I WAS UNABLE TO DO SO. WE CROSSED THE ARC APPROX 1000 FT HIGH WHILE I WAS TRYING TO SWITCH RADIOS AND XMITTERS. THE FO SELECTED DIRECT FTZ ON THE GPS AND WAS NOT ADDING THE ARC DISTANCE AWAY FROM FTZ TO THE DISTANCE HE WAS LOOKING AT. THE FO WAS FLYING. THE CTLRS NEVER MADE A COMMENT THAT I COULD RECALL.