Narrative:

The ATIS for pdx was calling for a ceiling of 4500 ft and the ILS runway 28L OTS. As the PNF, I wrote this down on the ATIS napkin, but did not verbally confirm this with my first officer. On approach to runway 28L, approach control initially gave us a vector to follow traffic and go through the final approach course. Once we got under the WX, I was pointing out landmarks to first officer, as this was his fist time into pdx. We were pretty busy looking for traffic that approach was calling out to us, while also trying to show the mill visual landmarks. Somewhere about 12 mi out, I pointed out the runway to first officer and assumed he also had it in sight. There were a few clouds, but certainly nothing to prevent us from flying a visual approach. I informed approach that we had the field in sight. Approach informed us that traffic in front of us was no factor and to maintain 2000 ft until laker (about 7 mi out), then cleared the visual to runway 28L. I had assumed first officer had the runway in sight. He did not. I assumed he also saw on the ATIS napkin that the ILS runway 28L was OTS. He did not. Once we were cleared for the visual, he was flying a bit right of course, but not too badly. He kicked off the autoplt and started to descend a bit rapidly (not too uncommon for someone with similar experience), but we clearly had the ground (as well as my having the runway) in sight, so I didn't feel all that uncomfortable. I thought he was just getting behind the aircraft and started giving verbal instructions such as 'come back left and don't descend.' first officer then replied something to the effect that he looked like he was on course. That's when I realized that he was trying to fly the ILS runway 28L that was giving false information (but had no flags in view). Through all this, I was busy trying to give instructions and point out the field. However, I had forgotten about the restr to maintain 2000 ft until laker. Approach control queried us as to our altitude (when we were abeam troutdale -- about where laker is) and if we still had the runway in sight. When I replied that we were at 1400 ft, he reminded us of the restr and reclred us for the visual to runway 28L. At this point I took the aircraft and positioned us for a normal approach and landing. I think 2 factors played a major role in this situation. First, I should have verbally confirmed with first officer that the ILS runway 28L was OTS. This would have prevented him from following the erroneous information and would have mentally prepared him to fly with no help from the NAVAID. Secondly, when the autoplt was disengaged, we lost the altitude acquire/hold mode. If the autoplt was still in use, even though we might have been off centerline, we still would have acquired and held 2000 ft as instructed. I did not say anything about disengaging the autoplt even though I know I should have. I thought I knew what he was thinking, and clearly I did not. That lack of communication resulted in descending before cleared. Supplemental information from acn 555716: I mentioned to the captain that I was unfamiliar with pdx and particularly the 'mills visual.' he said he would point out landmarks and talk me through it. The captain had the airport in sight and I told him I didn't, but that I did see some of the visual landmarks. I had my instruments tuned for the ILS runway 28L and was receiving course and GS guidance with no flags. Although I didn't have the field, I easily had the ground in sight and started to follow the localizer and GS. I couldn't find laker 2000 ft anywhere on my approach plates for ILS runway 28L nor mills visual runway 28L/right. A small rain shower was between us and the airport. I decided to follow my instruments slightly below GS in hopes of seeing the airport. I assumed the 2000 ft restr was behind us and no longer a factor since I had GS guidance. Approach control queried us on our altitude. The captain read back level at 1300 ft or 1400 ft. They asked what happened and I don't remember his response.

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Original NASA ASRS Text

Title: A B737-300 CREW, ON APCH TO PDX, DSNDED BELOW ATC'S ASSIGNED ALT.

Narrative: THE ATIS FOR PDX WAS CALLING FOR A CEILING OF 4500 FT AND THE ILS RWY 28L OTS. AS THE PNF, I WROTE THIS DOWN ON THE ATIS NAPKIN, BUT DID NOT VERBALLY CONFIRM THIS WITH MY FO. ON APCH TO RWY 28L, APCH CTL INITIALLY GAVE US A VECTOR TO FOLLOW TFC AND GO THROUGH THE FINAL APCH COURSE. ONCE WE GOT UNDER THE WX, I WAS POINTING OUT LANDMARKS TO FO, AS THIS WAS HIS FIST TIME INTO PDX. WE WERE PRETTY BUSY LOOKING FOR TFC THAT APCH WAS CALLING OUT TO US, WHILE ALSO TRYING TO SHOW THE MILL VISUAL LANDMARKS. SOMEWHERE ABOUT 12 MI OUT, I POINTED OUT THE RWY TO FO AND ASSUMED HE ALSO HAD IT IN SIGHT. THERE WERE A FEW CLOUDS, BUT CERTAINLY NOTHING TO PREVENT US FROM FLYING A VISUAL APCH. I INFORMED APCH THAT WE HAD THE FIELD IN SIGHT. APCH INFORMED US THAT TFC IN FRONT OF US WAS NO FACTOR AND TO MAINTAIN 2000 FT UNTIL LAKER (ABOUT 7 MI OUT), THEN CLRED THE VISUAL TO RWY 28L. I HAD ASSUMED FO HAD THE RWY IN SIGHT. HE DID NOT. I ASSUMED HE ALSO SAW ON THE ATIS NAPKIN THAT THE ILS RWY 28L WAS OTS. HE DID NOT. ONCE WE WERE CLRED FOR THE VISUAL, HE WAS FLYING A BIT R OF COURSE, BUT NOT TOO BADLY. HE KICKED OFF THE AUTOPLT AND STARTED TO DSND A BIT RAPIDLY (NOT TOO UNCOMMON FOR SOMEONE WITH SIMILAR EXPERIENCE), BUT WE CLRLY HAD THE GND (AS WELL AS MY HAVING THE RWY) IN SIGHT, SO I DIDN'T FEEL ALL THAT UNCOMFORTABLE. I THOUGHT HE WAS JUST GETTING BEHIND THE ACFT AND STARTED GIVING VERBAL INSTRUCTIONS SUCH AS 'COME BACK L AND DON'T DSND.' FO THEN REPLIED SOMETHING TO THE EFFECT THAT HE LOOKED LIKE HE WAS ON COURSE. THAT'S WHEN I REALIZED THAT HE WAS TRYING TO FLY THE ILS RWY 28L THAT WAS GIVING FALSE INFORMATION (BUT HAD NO FLAGS IN VIEW). THROUGH ALL THIS, I WAS BUSY TRYING TO GIVE INSTRUCTIONS AND POINT OUT THE FIELD. HOWEVER, I HAD FORGOTTEN ABOUT THE RESTR TO MAINTAIN 2000 FT UNTIL LAKER. APCH CTL QUERIED US AS TO OUR ALT (WHEN WE WERE ABEAM TROUTDALE -- ABOUT WHERE LAKER IS) AND IF WE STILL HAD THE RWY IN SIGHT. WHEN I REPLIED THAT WE WERE AT 1400 FT, HE REMINDED US OF THE RESTR AND RECLRED US FOR THE VISUAL TO RWY 28L. AT THIS POINT I TOOK THE ACFT AND POSITIONED US FOR A NORMAL APCH AND LNDG. I THINK 2 FACTORS PLAYED A MAJOR ROLE IN THIS SIT. FIRST, I SHOULD HAVE VERBALLY CONFIRMED WITH FO THAT THE ILS RWY 28L WAS OTS. THIS WOULD HAVE PREVENTED HIM FROM FOLLOWING THE ERRONEOUS INFO AND WOULD HAVE MENTALLY PREPARED HIM TO FLY WITH NO HELP FROM THE NAVAID. SECONDLY, WHEN THE AUTOPLT WAS DISENGAGED, WE LOST THE ALT ACQUIRE/HOLD MODE. IF THE AUTOPLT WAS STILL IN USE, EVEN THOUGH WE MIGHT HAVE BEEN OFF CTRLINE, WE STILL WOULD HAVE ACQUIRED AND HELD 2000 FT AS INSTRUCTED. I DID NOT SAY ANYTHING ABOUT DISENGAGING THE AUTOPLT EVEN THOUGH I KNOW I SHOULD HAVE. I THOUGHT I KNEW WHAT HE WAS THINKING, AND CLRLY I DID NOT. THAT LACK OF COM RESULTED IN DSNDING BEFORE CLRED. SUPPLEMENTAL INFO FROM ACN 555716: I MENTIONED TO THE CAPT THAT I WAS UNFAMILIAR WITH PDX AND PARTICULARLY THE 'MILLS VISUAL.' HE SAID HE WOULD POINT OUT LANDMARKS AND TALK ME THROUGH IT. THE CAPT HAD THE ARPT IN SIGHT AND I TOLD HIM I DIDN'T, BUT THAT I DID SEE SOME OF THE VISUAL LANDMARKS. I HAD MY INSTS TUNED FOR THE ILS RWY 28L AND WAS RECEIVING COURSE AND GS GUIDANCE WITH NO FLAGS. ALTHOUGH I DIDN'T HAVE THE FIELD, I EASILY HAD THE GND IN SIGHT AND STARTED TO FOLLOW THE LOC AND GS. I COULDN'T FIND LAKER 2000 FT ANYWHERE ON MY APCH PLATES FOR ILS RWY 28L NOR MILLS VISUAL RWY 28L/R. A SMALL RAIN SHOWER WAS BTWN US AND THE ARPT. I DECIDED TO FOLLOW MY INSTS SLIGHTLY BELOW GS IN HOPES OF SEEING THE ARPT. I ASSUMED THE 2000 FT RESTR WAS BEHIND US AND NO LONGER A FACTOR SINCE I HAD GS GUIDANCE. APCH CTL QUERIED US ON OUR ALT. THE CAPT READ BACK LEVEL AT 1300 FT OR 1400 FT. THEY ASKED WHAT HAPPENED AND I DON'T REMEMBER HIS RESPONSE.

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.