Air carrier first officer reported that they chose to utilize visual cues to crosscheck the LNAV/VNA...

Attributes
ACN	1472224
Time
Date	201708
Local Time Of Day	1801-2400
Place
Locale Reference	DCA.Airport
State Reference	DC
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Large Transport
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	Visual Approach
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 393
Events
Anomaly	Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT Inflight Event / Encounter Unstabilized Approach Inflight Event / Encounter Weather / Turbulence

Narrative:

We were cleared for visual approach at fergi intersection to runway 19 at dca. At start of approach all parameters on profile; however; after completing landing configuration by greyz intersection; I chose to go outside to utilize visual cues to follow the river to the runway vice crosschecking the LNAV/VNAV information. Undershooting crosswind from the left also compounded line-up to undershoot from the northwest. Momentary obstacle alert and simultaneous low altitude alert from tower resulted in immediate correction of approach navigational/line-up deviation resulting in uneventful landing. At no time was situational awareness comprised.better understanding and choice of LNAV/VNAV approach choices to be programmed into the FMC. I should have chosen to utilize RNAV (rnp) runway 19 approach which would have allowed me to couple aircraft to autopilot.

Original NASA ASRS Text

Title: Air carrier First Officer reported that they chose to utilize visual cues to crosscheck the LNAV/VNAV information; as a result they received an obstacle alert and a low altitude alert.

Narrative: We were cleared for visual approach at FERGI intersection to Runway 19 at DCA. At start of approach all parameters on profile; however; after completing landing configuration by GREYZ intersection; I chose to go outside to utilize visual cues to follow the river to the runway vice crosschecking the LNAV/VNAV information. Undershooting crosswind from the left also compounded line-up to undershoot from the northwest. Momentary obstacle alert and simultaneous low altitude alert from Tower resulted in immediate correction of approach navigational/line-up deviation resulting in uneventful landing. At no time was situational awareness comprised.Better understanding and choice of LNAV/VNAV Approach choices to be programmed into the FMC. I should have chosen to utilize RNAV (RNP) Runway 19 Approach which would have allowed me to couple aircraft to autopilot.

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.

Air carrier first officer reported that they chose to utilize visual cues to crosscheck the LNAV/VNAV information; as a result they received an obstacle alert and a low altitude alert.