C560 FLT CREW DISPUTES APCH CTLRS ASSERTION THEY DESCENDED BELOW THE CROSSING ALTITUDE AT EDDNA INTERSECTION ON THE MAIER RNAV START TO PHX.

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WE WERE DSNDING INTO THE PHOENIX ARPT ON THE MAIER ONE ARR. I WAS THE PF. WE DSNDED PER THE ARR AND AFTER PASSING THE EDDNA FIX WE WERE CALLED BY APCH CONTROL AND ADVISED THAT THEY THOUGHT WE HAD CROSSED THE FIX EARLY. WE IMMEDIATELY CLBED BACK TO 8000 FT. PRIOR TO THIS; ON THE INITIAL DSCNT; WE HAD BRIEFED THIS ARR BECAUSE WE HAD NOTICED THAT IT WAS PARTICULARLY BUSY WITH MULTIPLE RNAV STEP DOWNS; ALT AND AIRSPD RESTRS; AND HAD BRIEFED TO CALL POS AND ALTS. WE MADE EVERY STEP DOWN AND AIRSPD WITH NO PROBS UP TO THAT FIX. AT THAT FIX I ASKED THE PLT MONITORING TO SET ME DOWN FOR THE NEXT ALT ON THE ALT PRESELECT; WHICH WAS KUCOO AT 6000 FT. WHEN THE FMS SHOWED THAT WE WERE AT THIS FIX; I SELECTED THE FLC (FLT LEVEL CHANGE) BUTTON ON THE FLT DIRECTOR; AS WE WERE SPD RESTR TO 180 KTS; THEN BEGAN REDUCING THE PWR TO ACHIEVE THE PROPER RATE OF DSCNT AS TO CROSS KUCOO AT 6000 FT. THE CTLR SAID 'YOU CROSSED A LITTLE EARLY.' I LOOKED AT THE CRT AND IT SHOWED THAT WE HAD CROSSED THE EDDNA FIX. THE PLT MONITORING SAID TO THE CTLR 'WE SHOWED EDDNA AT 8000 AND KUCOO AT 6000.' SOME CONVERSATION TOOK PLACE ABOUT US BEING AT THE FIX AND WE SHOULD HAVE BEEN AT 8000. AT THAT POINT IT LOOKED AS WE WERE ALMOST AT CACTY INTXN. I IMMEDIATELY CLBED BACK TO 8000 FT AND AT THAT POINT WAS CONFUSED; BECAUSE WE CLRLY SHOWED WE WERE BEYOND EDDNA INTXN. WE TRIED TO EXPLAIN THAT WE HAD CROSSED THE EDDNA INTXN AT 8000 FT AND THE CTLR REPLIED 'WELL IF THAT'S TRUE THEN MY SCOPE MUST BE 25 MI OFF AND I NEED TO TALK TO MY SUPVR ABOUT THIS.' AT THIS POINT THE NAV UNIT WHICH WE HAD BEEN; UP TO NOW; PRETTY ACCURATE WAS NOW IN QUESTION AND MUCH TO MY CONFUSION COULD BE AS MUCH AS 25 MI IN ERROR. ONCE WE GOT SETTLED DOWN WE CONTINUED ON THE ARR AND LANDED. AT THAT POINT WE WERE GIVEN A PHONE NUMBER TO CALL. I HAVE SINCE COMPARED THE DATABASE IN THE AIRPLANE TO THE APCH PLATE AND THERE IS A MINOR DISCREPANCY IN THE DISTANCE ON THE PLATE BTWN THE FIX AT THE CACTY AT ONE TENTH OF A MI. I AM SURE THAT WE LOOKED AT THE FMS PRIOR TO SETTING THE ALT PRESELECT TO 6000 FT FOR KUCOO INTXN. I UNDERSTAND THAT THE CTLR; WITH WHAT HE WAS LOOKING AT; PROBABLY; SHOWED US LOW; BUT I AM ALSO SURE THAT WHAT I WAS LOOKING AT SHOWED THAT WE HAD CROSSED THE EDDNA FIX AT 8000 FT. UNFORTUNATELY; I CANNOT RECREATE WHAT I SAW. I CAN ONLY RECOUNT THE EVENTS AS BEST AS I CAN REMEMBER. I TRULY BELIEVE THAT WHAT THE CTLR SAW OR THOUGHT HE SAW HE BELIEVED TO BE CORRECT AND I CAN ONLY SAY THAT WHAT I SAW WAS WHAT I THOUGHT WAS CORRECT. I WOULD REALLY LIKE TO KNOW WHAT HAPPENED; AS I BELIEVE THERE IS AN ANOMALY IN THE DATABASE; BUT I CANNOT PROVE THIS. I HAVE BEEN FLYING FOR A LONG TIME AND AS A PROFESSIONAL PLT I RELY ON THE PROFESSIONALS ON THE GND AND THEY ARE TRULY THAT. I HAVE GIVEN THIS RECOLLECTION TO THE BEST OF MY ABILITY.