Date: 201412
Local time of day: 1201-1800
Location: BWI.Airport, MD
Flight conditions: IMC
Light: Daylight
Aircraft: MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B BWI
ATC / advisory: TRACON PCT
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Workload; Distraction; Communication Breakdown; Confusion
Anomaly: Deviation - Altitude Overshoot; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew FLC Overrode Automation; Flight Crew Became Reoriented; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Returned To Clearance
Contributing factors: Procedure; Human Factors
Primary problem: Human Factors

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.




Synopsis: 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.