Narrative:

I was PF this leg to phx. We were assigned the maier arrival; the first time my first officer or I had flown this new arrival. Through subsequent phone calls after landing; I learned this was also the first day phx was using this new arrival. During the descent on the arrival; while at 8000 ft altitude and 180 KTS; as depicted on the STAR; I unintentionally started the next descent down to be level at kucoo approximately 2.5 mi early; initially looking at the -700 situational display and 'thought' we were over eddna; but failed to confirm we were over eddna with the FMC. Since this was my first time doing this arrival; I had been also looking outside a little more than usual during the descent for the visual references on how this STAR was bringing us into the phx airport; and initially couldn't find sky harbor visually from the north; probably due to the sun angle/shadows. At 7500 ft on the altimeter; phx TRACON gave us a call telling us our low altitude. I was unaware of my deviation below the prescribed altitude at that time; but my first officer noticed the deviation just as TRACON made the call and told me we had started down from eddna a little early; and were 500 ft low. Neither of us noticed any traffic conflicts visually or on TCAS. Through my call after landing; this was also confirmed by TRACON. I also mentioned to the TRACON representative on the phone after landing that it was totally my error on the new arrival. The procedures for the new arrival are fine.

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Original NASA ASRS Text

Title: B737-700 FLT CREW HAS AN ALTDEV DURING THE MAIER1 PT MAIER ARR TO PHX.

Narrative: I WAS PF THIS LEG TO PHX. WE WERE ASSIGNED THE MAIER ARR; THE FIRST TIME MY FO OR I HAD FLOWN THIS NEW ARR. THROUGH SUBSEQUENT PHONE CALLS AFTER LNDG; I LEARNED THIS WAS ALSO THE FIRST DAY PHX WAS USING THIS NEW ARR. DURING THE DSCNT ON THE ARR; WHILE AT 8000 FT ALT AND 180 KTS; AS DEPICTED ON THE STAR; I UNINTENTIONALLY STARTED THE NEXT DSCNT DOWN TO BE LEVEL AT KUCOO APPROX 2.5 MI EARLY; INITIALLY LOOKING AT THE -700 SITUATIONAL DISPLAY AND 'THOUGHT' WE WERE OVER EDDNA; BUT FAILED TO CONFIRM WE WERE OVER EDDNA WITH THE FMC. SINCE THIS WAS MY FIRST TIME DOING THIS ARR; I HAD BEEN ALSO LOOKING OUTSIDE A LITTLE MORE THAN USUAL DURING THE DSCNT FOR THE VISUAL REFS ON HOW THIS STAR WAS BRINGING US INTO THE PHX ARPT; AND INITIALLY COULDN'T FIND SKY HARBOR VISUALLY FROM THE N; PROBABLY DUE TO THE SUN ANGLE/SHADOWS. AT 7500 FT ON THE ALTIMETER; PHX TRACON GAVE US A CALL TELLING US OUR LOW ALT. I WAS UNAWARE OF MY DEV BELOW THE PRESCRIBED ALT AT THAT TIME; BUT MY FO NOTICED THE DEV JUST AS TRACON MADE THE CALL AND TOLD ME WE HAD STARTED DOWN FROM EDDNA A LITTLE EARLY; AND WERE 500 FT LOW. NEITHER OF US NOTICED ANY TFC CONFLICTS VISUALLY OR ON TCAS. THROUGH MY CALL AFTER LNDG; THIS WAS ALSO CONFIRMED BY TRACON. I ALSO MENTIONED TO THE TRACON REPRESENTATIVE ON THE PHONE AFTER LNDG THAT IT WAS TOTALLY MY ERROR ON THE NEW ARR. THE PROCS FOR THE NEW ARR ARE FINE.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.