Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Communication Breakdown; Situational Awareness; Workload
Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance; Flight Crew Took Evasive Action
Human Factors; Procedure
ATC delayed switch from Approach to Tower led to TA and resulting altitude deviation causing a GPWS Caution. Tower then issued a low altitude alert. Helicopter traffic was heading up the Potomac while we were on the river visual approach did not alert us to the on coming traffic. By the time Tower responded we had a RA to descend which led to a GPWS and low altitude alert from Tower. We confirmed traffic in sight and maneuvered back on coarse to correct the deviation; in judgement the safety of flight was not compromised as such we continued the approach to landing on Runway 19. As I believe a go-around would have exacerbated the situation and led to further problems.
Air carrier Captain reported receiving a terrain caution message followed by a low altitude alert from ATC while responding to a traffic resolution advisory.