ACR B767-300 ON HIGH APCH; MAKES A GAR AFTER GPWS SOUNDS OFF.

Narrative

WE ARRIVED IAD FROM THE NE; AND WERE ASSIGNED RWY 1R. ATC HAD ASSIGNED US A SOUTHERLY HDG AT 3000 FT; AND ADVISED US THAT WE WERE #5 FOR APCH. JUST NE OF THE ARPT; ATC SAID TURN TO 240 DEG HDG AND RPT ARPT IN SIGHT; EXPECT RWY 19R. THE CAPT WAS FLYING AND CONTINUED SLOWING AND LOWERING FLAPS. WE RPTED ARPT IN SIGHT AND REQUESTED LOWER SINCE WE WERE CLOSE IN. ATC SAID UNABLE LOWER. WE WERE CLRED FOR VISUAL AND ADVISED TO CONTACT TWR; BUT BY THIS TIME WE WERE HIGH FOR APCH. IN ORDER TO ACCOMMODATE ATC AND CONTINUE FOR RWY 19R WE REQUESTED S-TURNS FROM THE TWR. ABOUT 500 FT AGL THE RATE OF DSCNT HAD INCREASED TO GET ON GS WHICH CAUSED A GPWS WARNING. A MISSED APCH WAS EXECUTED; WE STAYED WITH TWR; MADE R TFC BACK TO RWY 19R AND MADE A NORMAL APCH AND LNDG. THIS SIT COULD HAVE BEEN PREVENTED IF ATC HAD CLRED US FOR APCH EARLIER. SUPPLEMENTAL INFO FROM ACN 314674: AFTER ARRIVING AT MY HOME I CALLED DULLES APCH CTL AND SPOKE TO A SUPVR. I TOLD HER ABOUT OUR HANDLING AND OF BEING HELD TOO HIGH TOO LONG AND THEN OF HAVING TO GAR. I SUGGESTED THAT IT WAS NOT A GOOD PERFORMANCE. SHE SAID THAT SHE WOULD TALK TO THE CTLR WHO WORKED OUR FLT AND SHARE MY THOUGHTS WITH HER.