Narrative:

We were being vectored for the ILS runway 12R sat. When we were about 12 mi out on a 30 degree intercept, I told my student to descend from 4000 ft. The controller was busy and the radios were not very clear. ATC had only instructed us to turn to 090 degrees and intercept the localizer. I doubted myself, but allowed my student to descend anyway to 3000 ft, since this was the clearance I was used to getting every other time. To prevent this from happening again, I should pay more attention to my clearance.

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Original NASA ASRS Text

Title: A C172 CFI ALLOWED HIS STUDENT TO DSND BEFORE INTERCEPTING THE LOC IN SAT'S AIRSPACE.

Narrative: WE WERE BEING VECTORED FOR THE ILS RWY 12R SAT. WHEN WE WERE ABOUT 12 MI OUT ON A 30 DEG INTERCEPT, I TOLD MY STUDENT TO DSND FROM 4000 FT. THE CTLR WAS BUSY AND THE RADIOS WERE NOT VERY CLR. ATC HAD ONLY INSTRUCTED US TO TURN TO 090 DEGS AND INTERCEPT THE LOC. I DOUBTED MYSELF, BUT ALLOWED MY STUDENT TO DSND ANYWAY TO 3000 FT, SINCE THIS WAS THE CLRNC I WAS USED TO GETTING EVERY OTHER TIME. TO PREVENT THIS FROM HAPPENING AGAIN, I SHOULD PAY MORE ATTN TO MY CLRNC.

Data retrieved from NASA's ASRS site as of July 2007 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.