AN ATR42 FLC FAILS TO START THEIR DSCNT IN ACCORDANCE WITH ATC CLRNC WHEN THEY ARE DISTR BY A CONVERSATION ABOUT FLYING.

Narrative

WE WERE ABOUT 40 NM NW OF HNK VOR AND GIVEN A CLRNC TO CROSS HNK AT AND MAINTAIN 15000 FT. THE FO WAS FLYING AND DECIDED TO STAY AT 17000 FT UNTIL 10 NM NW OF HNK AND THEN START A DSCNT. HE LATER ASKED ME A QUESTION AND WE STARTED TALKING ABOUT PAST FLYING EXPERIENCES AND GOT DISTR FROM OUR 10 NM DSCNT POINT AND ENDED UP XING THE HNK VOR AT 17000 FT. THE CTLR MUST HAVE BEEN WATCHING US ON RADAR BECAUSE RIGHT AT HNK HE REQUESTED OUR ALT. NO TFC WAS IN THE AREA SO HE ASKED US TO START OUR DSCNT TO 15000 FT AND GAVE US A FREQ CHANGE. THE PROB OF COURSE WAS DUE TO THE FO'S DECISION TO DELAY THE DSCNT FOLLOWED BY OUR INATTN TO THE DSCNT POINT BY GETTING DISTR BY CONVERSATION. SUCH DEVS CAN BE REDUCED BY STARTING AT LEAST A SLOW INITIAL DSCNT WHEN GIVEN SUCH AN ENRTE XING RESTR OR BY SIMPLY AVOIDING DISTRS WHEN HOLDING OFF ON MAKING SUCH DSCNTS. SUPPLEMENTAL INFO FROM ACN 405078: FROM NOW ON WHEN ISSUED A DSCNT I WILL START A SLOW DSCNT TO THE ALT SO THAT THERE WILL BE MORE VISUAL CUES TO KEEP ME AWARE OF OUR POS. ALSO GETTING INVOLVED IN A CONVERSATION AFTER RECEIVING SUCH A CLRNC PROBABLY CONTRIBUTED TO DEV.