Narrative:

While proceeding to toy on UW208 at FL370; and getting ready for a descent into mountainous terrain rising above 19000 ft; santiago center was notified that we were ready for descent. They cleared us to descend to FL260 and to proceed direct to tbn. The crossing altitude for tbn on the ANDES1 approach to scel is FL090A. I twice refused this clearance; and told center I would proceed directly to the TBN60 fix with a crossing altitude of FL210A. This took us close to toy. While on the approach radial descending to FL150; center came on and scolded me for not proceeding direct to tbn; that I had caused a conflict. I was unwilling to take a significant vector and descent into very irregular mountainous terrain hidden in an undercast relying only on egpws and center for terrain clearance. I exercised captain emergency authority/authorized to stay on the published approach for this descent. Language confusion may have played a part.

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Original NASA ASRS Text

Title: B767 CAPT REFUSES A DIRECT CLRNC FROM SCEZ CTR DUE CONCERNS ABOUT HIGH TERRAIN AND BEING OFF THE ARR DURING THE DSCNT.

Narrative: WHILE PROCEEDING TO TOY ON UW208 AT FL370; AND GETTING READY FOR A DSCNT INTO MOUNTAINOUS TERRAIN RISING ABOVE 19000 FT; SANTIAGO CTR WAS NOTIFIED THAT WE WERE READY FOR DSCNT. THEY CLRED US TO DSND TO FL260 AND TO PROCEED DIRECT TO TBN. THE XING ALT FOR TBN ON THE ANDES1 APCH TO SCEL IS FL090A. I TWICE REFUSED THIS CLRNC; AND TOLD CTR I WOULD PROCEED DIRECTLY TO THE TBN60 FIX WITH A XING ALT OF FL210A. THIS TOOK US CLOSE TO TOY. WHILE ON THE APCH RADIAL DSNDING TO FL150; CTR CAME ON AND SCOLDED ME FOR NOT PROCEEDING DIRECT TO TBN; THAT I HAD CAUSED A CONFLICT. I WAS UNWILLING TO TAKE A SIGNIFICANT VECTOR AND DSCNT INTO VERY IRREGULAR MOUNTAINOUS TERRAIN HIDDEN IN AN UNDERCAST RELYING ONLY ON EGPWS AND CTR FOR TERRAIN CLRNC. I EXERCISED CAPT EMER AUTH TO STAY ON THE PUBLISHED APCH FOR THIS DSCNT. LANGUAGE CONFUSION MAY HAVE PLAYED A PART.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.