Guys, DCA ops ain't difficult.
DCA
DCA328/30
AML/BUFFR/other departure gate fix
If VMC, takeoff, at 400' or the departure end of the runway turn left toward the west bank of Roosevelt Island (which keeps you along the west bank of the Potomac), then another left turn immediately passing Rossyln for a few seconds before coming back right to intercept the white-needles 328° radial following the river northwest. This easily keeps you clear of P56A/B *and* avoids the noise-sensitive areas on the Virginia side of the river.
If you start a left turn at 400' immediately after 'gear-up' like some folks do, you will fly right over Rosslyn (if not clipping the NE corner of the Pentagon) and your airline WILL hear about it in the weekly DCA ops meeting, where they list every noise complaint they receive (with animated radar tracks of the offending aircraft). Yes, you in a CRJ passing overhead at 2000' are just as offensive in their eyes as the American MD80 that goes thundering 900' overhead.
Wash Metro Airports Authority wants crews to remain over the river as much as practical for noise abatement and stresses this point to DCA station managers in their meeting. Some pilots say "screw noise complaints, I'm not going to risk my certificates for that" but in VFR conditions it is not even remotely risky in terms of a P56 violation to visually follow the river northwest...but you gotta make that second left turn over Roosevelt Island passing Rosslyn to stay away from the Naval Observatory (P-56B).