Narrative:

We were on vectors for the ILS runway 10 approach at bwi. Conditions were IMC; CAT I. Potomac approach turned us to a base heading and directed a further descent to 2;000 feet; we were already descending to 3;000. As pilot monitoring; I was heads down; setting up the FMS to extend final approach course from jeans; while the captain flew the turning descent. In the meantime; potomac gave us our turn to intercept the localizer. I think the intercept angle was right at 30 degrees; but do not remember the exact heading given. I was asking for the captain's confirmation of the FMS setup; prior to executing the change; when the altitude aural alert sounded. I looked up to see we were leveling off between 1;500 and 1;600 feet; and that the auto pilot red ap fail lights were flashing. The captain confirmed we were correcting back toward 2;000 feet. Potomac approach called us to say they showed us at 1600 feet; but we were supposed to be at 2000 feet. We acknowledged; and told potomac we were correcting back to assigned altitude. The captain said the elevator trim felt heavy; and she was not sure if that had caused the ap disconnect; or if she might have disconnected the auto pilot on reflex when the alert went off. She hand flew as she made initial corrections and re-trimmed the aircraft. During the altitude transient and autopilot disconnect; we had also failed to capture the localizer; so we told potomac we had overshot and were turning right to re-intercept. Potomac asked if we would like to be vectored around for another approach; or if we would continue. We opted to continue; as we felt we could regain the localizer prior to jeans. We were able to do so; and from jeans inbound were able to fly a stable approach to an uneventful landing.

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Original NASA ASRS Text

Title: An air carrier crew on final approach overshot an assigned altitude by 400 feet. They also failed to capture the localizer; but they corrected and continued to an uneventful landing.

Narrative: We were on vectors for the ILS RWY 10 approach at BWI. Conditions were IMC; CAT I. Potomac Approach turned us to a base heading and directed a further descent to 2;000 feet; we were already descending to 3;000. As Pilot Monitoring; I was heads down; setting up the FMS to extend final approach course from JEANS; while the Captain flew the turning descent. In the meantime; Potomac gave us our turn to intercept the localizer. I think the intercept angle was right at 30 degrees; but do not remember the exact heading given. I was asking for the Captain's confirmation of the FMS setup; prior to executing the change; when the altitude aural alert sounded. I looked up to see we were leveling off between 1;500 and 1;600 feet; and that the Auto Pilot red AP fail lights were flashing. The Captain confirmed we were correcting back toward 2;000 feet. Potomac Approach called us to say they showed us at 1600 feet; but we were supposed to be at 2000 feet. We acknowledged; and told Potomac we were correcting back to assigned altitude. The Captain said the elevator trim felt heavy; and she was not sure if that had caused the AP disconnect; or if she might have disconnected the Auto Pilot on reflex when the alert went off. She hand flew as she made initial corrections and re-trimmed the aircraft. During the altitude transient and autopilot disconnect; we had also failed to capture the localizer; so we told Potomac we had overshot and were turning right to re-intercept. Potomac asked if we would like to be vectored around for another approach; or if we would continue. We opted to continue; as we felt we could regain the localizer prior to JEANS. We were able to do so; and from JEANS inbound were able to fly a stable approach to an uneventful landing.

Data retrieved from NASA's ASRS site 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.