LEARJET 60 FLC RECEIVES RA ON APCH TO LAS.

Narrative

AS WE APCHED THE CITY FROM THE W APPROX 20 MI OUT; WE WERE CLRED FOR A VISUAL APCH. THAT WAS THEN MODIFIED TO: 'PROCEED TO THE STRATOSPHERE; THEN YOU ARE CLRED FOR THE VISUAL; AND BE ADVISED THAT THERE ARE 2 NAVAJOS OPPOSITE DIRECTION AT 3500 FT.' WE WERE PROCEEDING TO THE STRATOSPHERE. ON THE WAY THERE; THE CTLR GAVE US A THIRD CLRNC ('MAINTAIN 4000 FT TILL FINAL; INSIDE THE SHOWBOAT.) IF YOU ARE FAMILIAR WITH THE LAS VEGAS AREA; YOU MIGHT KNOW THAT THE SHOWBOAT IS FURTHER AWAY FROM THE RWY THAN THE STRATOSPHERE. KNOWING THAT; I ELECTED TO START MY APCH RIGHT AROUND THE STRATOSPHERE. AS SOON AS I STARTED THE DSCNT ON THE FINAL; THE TCASII ALERTED US OF AN RA. I IMMEDIATELY TOOK ACTION AND WHEN I LOOKED AT THE TYPE OF ACFT; I NOTICED THAT THEY APPEARED TO BE 2 DORNIER 328'S! A DORNIER 328 IS A LOT FASTER THAN A NAVAJO. I ESTIMATED THAT THEY WERE DOING 250 KTS DIRECTLY OPPOSITE US AT THIS POINT. WITH OUR SPD OF 180 KTS THAT MAKES A CLOSURE RATE OF 430 KTS! (RIGHT AT OUR FINAL TO THE ARPT.) I BELIEVE WE DID EVERYTHING POSSIBLE TO MEET OUR CLRNC LIMIT; HOWEVER; A LEAR 60 DOES NOT SLOW DOWN AND COME DOWN AT THE SAME TIME; ESPECIALLY WITH PAX ON BOARD. I USED THE STRATOSPHERE AS A REF POINT FOR OUR APCH AND IT IS APPROX 2.5 MI FROM THE END OF THE RWY; AS WELL AS BEING CLOSER THAN THE SHOWBOAT. WE WERE 2000 FT ABOVE THE GND AND NEEDED TO LOSE ALT TO CONFIGURE AND LAND. HAVING TFC XING AT THIS POINT DOING 250 KTS; I BELIEVE WAS NOT A GOOD CALL ON APCH CTL'S BEHALF. I THINK IF THEY WOULD HAVE CLRED US TO MAINTAIN 4000 FT UNTIL FURTHER ADVISED; THAT WOULD HAVE BEEN A SAFER DECISION. THE WHOLE SIT COULD THEN HAVE BEEN AVOIDED.