A300 FLT CREW SLOWS TO APCH SPD AT REEBO FAF ON THE LOC-DME RWY 27 SAN TOO SOON AND CTLR COMMENTS ON POS.

Narrative

MANUFACTURER OF ON-BOARD FMS HAS DELISTED DME'S FOR THE SAN DIEGO APCHS (IE; ILS-9 LOC 27). FAA HAS APPROVED THE USE OF OUR ND (NAV DISPLAY/MAP FEATURE) TO BE A SUITABLE MEANS OF IDENTING FIXES OR INTXNS ON THESE APCHS. WE WERE CLRED FOR LOC-27 OUTSIDE SWATT INTXN TO MAINTAIN 180 KIAS UNTIL THE FAF (REEBO). AS SHOWN ON OUR FMS NAV DISPLAY; OUR POS TO AGGRESSIVELY SLOW TO APCH SPD OF 135 KIAS; WAS OVER REEBO. THE DIGITAL COUNTER AT REEBO SHOWED '0.' SOCAL APCH REQUESTED OUR AIRSPD AND REMARKED THAT THEIR READING IMAGE SHOWED US SLOWING IN CONFLICT WITH OUR CLRNC. IT WAS THEIR BELIEF THAT WE HAD SLOWED 1.5 MI TOO SOON. GIVEN OUR POS AS PRESENTED TO US BY OUR NAV EQUIP; WE RESPECTFULLY DISAGREED. IT APPEARS THAT DME'S LISTED FOR THIS APCH WOULD HAVE MORE ACCURATELY DETERMINED OUR POS THAN THE ALTERNATIVE NAV DISPLAY CURRENTLY IN USE. SUPPLEMENTAL INFO FROM ACN 696688: SUBSEQUENT CONVERSATION WITH SOCAL APCH SHOWS THERE IS A 1.5 MI DIFFERENCE BTWN THE ACFT POS ON THEIR RADAR AND THE AFT POS INDICATED ON THE NAV DISPLAY (ACFT 1.5 MI FURTHER E).