Narrative:

On approach to zurich; 4000 ft on vectors for the ILS 14; we were told to hold 4000 ft till established on the localizer. The controller said something to us which I didn't understand. The captain told me to descend and I asked again what the instructions had been. The captain again told me to descend. I started a descent to 3000 ft then the controller asked our altitude and why we were descending. The captain pressed altitude hold and we leveled off at 3200 ft. The controller asked again why we were descending. The captain had thought we were above the GS instead of below. Supplemental information from acn 797283: I'm the relief pilot on a 3-MAN crew. The captain is a line check airman administering a transoceanic operating experience to a first yr new hire. After receiving clearance to the initial approach altitude; approach asked for a wind readout. This distraction the captain and situational awareness was momentarily lost causing the captain to 'feel' he was high on the glide path when actually the aircraft was below the glide path. Captain directed a descent below the initial approach altitude and shortly thereafter; zurich approach called our flight twice that we were below the glide path intercept published altitude. We descended 400 ft below published intercept altitude and then leveled off to recapture and proceed with the approach.

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Original NASA ASRS Text

Title: B767 FLT CREW DESCENDS BELOW ASSIGNED ALT WHEN CAPT LOSES SITUATIONAL AWARENESS AND ORDERS A DESCENT PREMATURELY DURING APPROACH.

Narrative: ON APCH TO ZURICH; 4000 FT ON VECTORS FOR THE ILS 14; WE WERE TOLD TO HOLD 4000 FT TILL ESTABLISHED ON THE LOC. THE CTLR SAID SOMETHING TO US WHICH I DIDN'T UNDERSTAND. THE CAPT TOLD ME TO DSND AND I ASKED AGAIN WHAT THE INSTRUCTIONS HAD BEEN. THE CAPT AGAIN TOLD ME TO DSND. I STARTED A DSCNT TO 3000 FT THEN THE CTLR ASKED OUR ALT AND WHY WE WERE DSNDING. THE CAPT PRESSED ALT HOLD AND WE LEVELED OFF AT 3200 FT. THE CTLR ASKED AGAIN WHY WE WERE DSNDING. THE CAPT HAD THOUGHT WE WERE ABOVE THE GS INSTEAD OF BELOW. SUPPLEMENTAL INFO FROM ACN 797283: I'M THE RELIEF PLT ON A 3-MAN CREW. THE CAPT IS A LINE CHK AIRMAN ADMINISTERING A TRANSOCEANIC OPERATING EXPERIENCE TO A FIRST YR NEW HIRE. AFTER RECEIVING CLRNC TO THE INITIAL APCH ALT; APCH ASKED FOR A WIND READOUT. THIS DISTR THE CAPT AND SITUATIONAL AWARENESS WAS MOMENTARILY LOST CAUSING THE CAPT TO 'FEEL' HE WAS HIGH ON THE GLIDE PATH WHEN ACTUALLY THE ACFT WAS BELOW THE GLIDE PATH. CAPT DIRECTED A DSCNT BELOW THE INITIAL APCH ALT AND SHORTLY THEREAFTER; ZURICH APCH CALLED OUR FLT TWICE THAT WE WERE BELOW THE GLIDE PATH INTERCEPT PUBLISHED ALT. WE DSNDED 400 FT BELOW PUBLISHED INTERCEPT ALT AND THEN LEVELED OFF TO RECAPTURE AND PROCEED WITH THE APCH.

Data retrieved from NASA's ASRS site as of May 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.