Narrative:

Weather was clear with unlimited visibility; airport winds were reported by tower as 080 degrees at 7 KTS. The runway surface was dry. We were cleared for the visual approach to the left runway and approach control handed us off to tower right around the outer marker. We checked in with tower and we were cleared to land. The approach was stable and the aircraft was nearly fully configured for landing. Shortly after landing clearance was received we heard what sounded like a circuit breaker 'pop' and we immediately loss numerous systems including; but not limited to; one fuel pump from each main tank; yaw dampener; 'B' system electric hydraulic pump; comm #1 audio panel; antiskid; and the dome light illuminated on dim. I was already hand flying so the autopilot was not engaged at the time. The captain and I quickly discussed the problem and decided to continue the approach to the runway since we were now approximately three miles from touchdown; below 2000 ft MSL and landing was assured. We were not able to declare an emergency due to the fact we were trying to diagnose the problem as well as fly in a critical phase of flight. In addition; since we already communicated with the tower we made a late discovery that the comm #1 audio panel had also failed. We knew that we had a major electrical issue and we mutually decided that it was safer to continue the landing since we now had the aircraft fully configured and were on short final. Additionally; we were comfortable with our landing performance due to our light aircraft landing weight; dry runway; long runway length and favorable winds. The landing was uneventful. The aircraft was easily stopped with virtually no manual braking and one operating thrust reverser; which we were prepared for. We cleared the runway; communicated with ATC on the comm #2 audio panel; and taxied to the gate uneventfully. Oddly; after clearing the runway and turning off the landing lights; all the failed systems returned to normal. We also later learned from the flight attendants that the emergency lights had also illuminated while in flight. Maintenance control was contacted and we provided the details of the flight and wrote up the discrepancy in the maintenance logbook. Contract maintenance arrived and we debriefed the mechanic of the episode. Other considerations: we did not feel comfortable executing a go-around under these conditions since we had multiple critical aircraft systems affected by the electrical issue. Plus; we did not want to take the chance in case of the possibility of aircraft fire. If we had more time we would have been able to declare an emergency with ATC; but not only was time an issue; but we also lost the comm #1 audio panel.

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Original NASA ASRS Text

Title: A B737-400 flight crew continued the approach and landed when they suffered multiple electrical anomalies after already configured for landing. Later it was determined the faults were the result of the number one transformer/rectifier circuit breaker opening.

Narrative: Weather was clear with unlimited visibility; airport winds were reported by Tower as 080 degrees at 7 KTS. The runway surface was dry. We were cleared for the visual approach to the left runway and Approach Control handed us off to Tower right around the outer marker. We checked in with Tower and we were cleared to land. The approach was stable and the aircraft was nearly fully configured for landing. Shortly after landing clearance was received we heard what sounded like a circuit breaker 'pop' and we immediately loss numerous systems including; but not limited to; one fuel pump from each main tank; yaw dampener; 'B' system electric hydraulic pump; COMM #1 audio panel; antiskid; and the dome light illuminated on dim. I was already hand flying so the autopilot was not engaged at the time. The Captain and I quickly discussed the problem and decided to continue the approach to the runway since we were now approximately three miles from touchdown; below 2000 FT MSL and landing was assured. We were not able to declare an emergency due to the fact we were trying to diagnose the problem as well as fly in a critical phase of flight. In addition; since we already communicated with the tower we made a late discovery that the COMM #1 audio panel had also failed. We knew that we had a major electrical issue and we mutually decided that it was safer to continue the landing since we now had the aircraft fully configured and were on short final. Additionally; we were comfortable with our landing performance due to our light aircraft landing weight; dry runway; long runway length and favorable winds. The landing was uneventful. The aircraft was easily stopped with virtually no manual braking and one operating thrust reverser; which we were prepared for. We cleared the runway; communicated with ATC on the COMM #2 audio panel; and taxied to the gate uneventfully. Oddly; after clearing the runway and turning off the landing lights; all the failed systems returned to normal. We also later learned from the flight attendants that the emergency lights had also illuminated while in flight. Maintenance Control was contacted and we provided the details of the flight and wrote up the discrepancy in the maintenance logbook. Contract maintenance arrived and we debriefed the Mechanic of the episode. Other considerations: We did not feel comfortable executing a go-around under these conditions since we had multiple critical aircraft systems affected by the electrical issue. Plus; we did not want to take the chance in case of the possibility of aircraft fire. If we had more time we would have been able to declare an emergency with ATC; but not only was time an issue; but we also lost the COMM #1 audio panel.

Data retrieved from NASA's ASRS site as of April 2012 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.