Beechjet 400
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 150; Flight Crew Total 7800; Flight Crew Type 2200
Communication Breakdown
ATC Issue All Types; Airspace Violation All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Procedure; Human Factors
We received an IFR clearance from Washington Clearance delivery for a direct flight from DCA direct via radar vectors with an initial altitude of 4000ft.  Upon reaching the runway for takeoff; Washington tower stated 'cleared for takeoff' without any type of departure instructions; i.e. a heading to avoiding the prohibited area north of DCA.  We knew we could not continue straight ahead without going into prohibited airspace.  We queried again as we were taking off.  Washington tower replied; 'follow the river and intercept the 328 radial; contact Potomac approach'.  We made a left turn to follow the river and intercept the 328 radial.  While following the river and intercepting the 328 radial off of DCA (VOR); we contacted Potomac approach and were told to turn west to a heading of 320 degrees; and then 270 degrees to avoid a prohibited area.  Not sure if we entered the southwestern edge of the prohibited area north of DCA or not; but would like to have had more timely instructions from tower; be given a SID; a departure procedure of some type before we were given a takeoff clearance; or a heading to follow immediately upon departure.
IFR departure voiced concern regarding the lack of initial departure instructions departing DCA; especially considering the multiple restricted areas in the vicinity.