FLC DSNDS ACFT ON SID ARR TOO SOON WHEN READING WRONG DME FOR APCH. ASSOCIATED WITH ACFT EQUIP PROB. NAV ERROR.

Narrative

WHILE TRANSITIONING TUS-LAX; IT WAS DETERMINED THE ONS WAS UNRELIABLE. THE #2 DME WAS ERRATIC AND SLOW TO LOCK ON A SELECTED STATION. PROCEEDING DIRECT TNP FROM GBN; ZLA CLRED US DIRECT CIVET; CIVET ARR LAX. WE ADVISED ZLA THAT THE ONS WAS UNRELIABLE FOR POINT TO POINT NAV BECAUSE OF DRIFT AND DME PROBS. ZLA THEN CLRED US PRESENT POS DIRECT POMONA VOR TO INTERCEPT THE ILS RWY 25L LOC (LAX); CIVET ARR LAX. PROCEEDING AS CLRED; THE #2 DME WOULD NOT LOCK ON RWY 25L LOC DME (LAX) THE ONS WAS UNRELIABLE; THEREFORE SWITCHING #1 DME FROM POMONA TO ILAX WOULD HAVE GIVEN US DME FOR THE CIVET. DURING THE NUMEROUS SWITCHES; THE #1 DME POMONA WAS MISTAKEN FOR ILAX. A DSCNT WAS ACCOMPLISHED TO MEET ALT REQUIREMENTS AT CIVET AND BREMR. AT 12000 FT; FOR WHAT WE THOUGHT WAS BREMR INTXN; (USING POMONA DME); LCL APCH ASKED ABOUT OUR REFS FOR DME AND AZIMUTH. WHEN WE INFORMED THEM OF OUR OBTUSE CLRNC; THEY REQUESTED WE CLB TO 13000 FT AND RECOMMENCE THE CIVET ARR AT BREMR (LAX RWY 25L LOC DME). THIS WAS ACCOMPLISHED ALONG WITH AN UNEVENTFUL LNDG.