Date: 201509
Local time of day: 1201-1800
Location: DCA.Airport, DC
Flight conditions: IMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Medium Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B DCA
ATC / advisory: Tower DCA
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction; Situational Awareness; Workload; Training / Qualification
Anomaly: Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT; Inflight Event / Encounter Unstabilized Approach
Detector: Automation Aircraft Terrain Warning; Person Flight Crew
When detected: In-flight
Result: Flight Crew FLC complied w / Automation / Advisory; Flight Crew Returned To Clearance; Flight Crew Took Evasive Action
Contributing factors: Airport; Weather; Procedure; Human Factors; Environment - Non Weather Related
Primary problem: Procedure

Narrative: On approach to Runway 19 at DCA; flying the RNAV RNP 19.  Ceiling reported 3000 BKN.  We were expecting to break out and see the airport further out than we did. Began breaking out around 1500' AGL.  As PM my attention became primarily focused outside as we descended into visual conditions (Verifying our position relative to the P-56 area; and looking for airport.) As we got closer to airport around JUBOL; it became apparent that we were getting low on the approach.  I looked inside and noticed our altitude was much lower than it should have been at that point on the approach.  The altitude at JUBOL is published as 955. The same point on the RIVER VISUAL is recommended 900. We were at approximately 700' and still descending.  I alerted the PM that we were getting very low. At about that same time the GPWS alerted 'CAUTION TERRAIN' 'OBSTACLE; OBSTACLE' 'PULL UP'. The PF immediately began a climb; he did not initiate a go-around because he didn't hear the warning; and although I did; I did not call for a go-around (although I should have).  The alerts were obviously initiated be a tall building very near the approach path around JUBOL. All obstacles and terrain were in clear view during the event; and once we were back up to the appropriate altitude; we both felt comfortable in safely continuing the approach.  The aircraft was descending earlier in the approach in VNAV PATH; but somewhere outside of JUBOL changed into VNAV SPEED. I didn't notice this when it occurred.I did not perform well as PM. My attention was more outside than it should have been; therefore I did not notice that the aircraft was no longer on path and getting too low until it was very obvious. I also should have called a go-around even though the aircraft was in day VMC and the terrain and obstacles were in sight. I was preoccupied with watching our ground track because of our proximity to prohibited airspace; and the unique path over the ground required.




Synopsis: A flight crew descended below the DCA RNAV RNP Runway 19 crossing altitudes and at about 700 ft the EGPWS alerted 'CAUTION TERRAIN' 'OBSTACLE; OBSTACLE' 'PULL UP.' The pilot flying responded and continued to land. The crew did not see the autopilot transition from VNAV PATH to VNAV SPD.