B737 CREW NEARLY PENETRATES P56 DEPARTING DCA RWY 1 BY NOT TURNING AGGRESSIVELY ENOUGH.

Narrative

WX AT DCA AT TIME OF DEP WAS 500 FT OVCST; 1 3/4 MI VISIBILITY WINDS 200 DEGS AT 4 KTS DEPARTING RWY 1. THE CAPT WAS MAKING THE TKOF AND EXECUTED A TURN USING THE HUD TO INTERCEPT THE 328 DEG RADIAL OFF OF DCA FREQ 111.00 AS IS REQUIRED UNDER IMC CONDITIONS. THE TURN WAS MADE AT 300 FT FOLLOWING THE HUD HDG SELECT COMMANDS TOWARDS THE 328 DEG RADIAL. THE FO NOTICED THE GND TRACK WITH THE SHALLOW BANK PROGRAMMED IN THE FLT DIRECTOR SYS WAS NOT TURNING US AWAY FROM THE PROHIBITED AIRSPACE. THE FO ANNOUNCED A NEED TO INCREASE THE BANK ANGLE TO TAKE UP A MORE WESTERLY HDG TO GET OVER TO THE 328 DEG RADIAL. DURING THE TURN AWAY FROM THE PROHIBITED AIRSPACE; DEP CALLED US TO ADVISE US OF OUR PROX TO THE PROHIBITED BOUNDARIES. AFTER MAKING THE TURN AND JOINING THE 328 DEG RADIAL OUTBOUND; WE INQUIRED WITH DEP AS TO OUR COMPLIANCE WITH THE DEP PROC. DEP INDICATED WE REACHED THE 'LINE' THAT DEFINES THE PROHIBITED AIRSPACE. ON FURTHER INQUIRY DEP DID NOT SEE A PROB WITH OUR GND TRACK OR COMPLIANCE WITH THE DEP PROC. DURING THE CRUISE PORTION OF THE FLT THE FO AND I DISCUSSED WHAT MIGHT HAVE CAUSED US TO COME SO CLOSE TO THE DEP LIMITATIONS. FIRST THE QUARTERING TAILWIND WHICH WAS NOT A TKOF PROB DID AFFECT OUR GND TRACK IN SUCH A WAY AS TO CAUSE US TO DRIFT OUT OF THE TURN RADIUS. ALSO THE HUD WHICH IS VALUABLE IN TKOF PARTICULARLY IN IMC DOES NOT AGGRESSIVELY CTL THE ACFT AS IS NEEDED IN THIS DEP. FINALLY; THE FLT DIRECTOR SYS HAS LIMITATIONS BUILT IN TO PROVIDE BANK ANGLE LIMITS DURING LOW ALT LOW AIRSPACE FLT AND IF FOLLOWED DO NOT COMPLY WITH THE DEP RESTRS. THE NOISE ABATEMENT PROC/P56 AVOIDANCE DEP PROC RWY 1 AT DCA IS A DEMANDING DEP REQUIRING SITUATIONAL AWARENESS AND SPECIFIC CONDITIONAL INTERP TO COMPLY WITH IT.