Narrative:

On jan/sun/02, we were on an IFR flight from sea to pdx. During the descent into the pdx area, the captain recorded the pdx ATIS. The ceiling was reported to be approximately 3500 ft broken with 10 mi visibility. The ATIS said to expect runways 28R or runway 28L using the ILS or mill visual approach. We expected the mill visual. The captain also briefed the ILS approach. Pdx approach had us on a vector to intercept the final approach course for runway 28R. We were cleared down to 3000 ft MSL first, then 2500 ft MSL, and finally 2000 ft MSL. At 2000 ft MSL, we had ground contact, but could not see the airport. ATC cleared us for the ILS runway 28R. I intercepted the localizer at approximately 8 NM. I noticed that in the turn, the aircraft was at an altitude of 1800 ft MSL and below the GS. I corrected by adding power and increasing pitch. ATC informed us while I was correcting of a low altitude alert. I returned to 2000 ft MSL, intercepted the GS, and continued the approach. The rest of the flight was uneventful.

Related reports:

Google
 

Original NASA ASRS Text

Title: EMB120 FO DSNDED BELOW ASSIGNED VECTORING ALT DURING VECTOR TO AN ILS APCH RESULTING IN AN ATC LOW ALT ALERT.

Narrative: ON JAN/SUN/02, WE WERE ON AN IFR FLT FROM SEA TO PDX. DURING THE DSCNT INTO THE PDX AREA, THE CAPT RECORDED THE PDX ATIS. THE CEILING WAS RPTED TO BE APPROX 3500 FT BROKEN WITH 10 MI VISIBILITY. THE ATIS SAID TO EXPECT RWYS 28R OR RWY 28L USING THE ILS OR MILL VISUAL APCH. WE EXPECTED THE MILL VISUAL. THE CAPT ALSO BRIEFED THE ILS APCH. PDX APCH HAD US ON A VECTOR TO INTERCEPT THE FINAL APCH COURSE FOR RWY 28R. WE WERE CLRED DOWN TO 3000 FT MSL FIRST, THEN 2500 FT MSL, AND FINALLY 2000 FT MSL. AT 2000 FT MSL, WE HAD GND CONTACT, BUT COULD NOT SEE THE ARPT. ATC CLRED US FOR THE ILS RWY 28R. I INTERCEPTED THE LOC AT APPROX 8 NM. I NOTICED THAT IN THE TURN, THE ACFT WAS AT AN ALT OF 1800 FT MSL AND BELOW THE GS. I CORRECTED BY ADDING PWR AND INCREASING PITCH. ATC INFORMED US WHILE I WAS CORRECTING OF A LOW ALT ALERT. I RETURNED TO 2000 FT MSL, INTERCEPTED THE GS, AND CONTINUED THE APCH. THE REST OF THE FLT WAS UNEVENTFUL.

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.