AN A320 CREW; TAXIING FOR TKOF AT DCA; TAXIED PAST THE HOLD SHORT LINE.

Narrative

PUSHED BACK FROM DCA GATE; SHORT TAXI TO RWY 19. I LOADED PERFORMANCE DATA INTO FMS; AFTER WHICH THE CAPT AND I ACCOMPLISHED THE BEFORE TKOF CHKLIST. AS WE APCHED THE RWY; THE GND CTLR INSTRUCTED US TO CONTACT THE TWR WITH THE EXPECTATION THAT WE WOULD BE 'GOING RIGHT OUT.' IN AN EFFORT TO ASSIST ME IN MY CHKLIST ITEMS; THE CAPT LEFT THE FREQ TO ADVISE THE FLT ATTENDANTS AND PAX OF OUR IMMINENT DEP. I SWITCHED TO THE TWR FREQ WITH THE UNDERSTANDING THAT THE CAPT KNEW THAT WE HAD NOT YET BEEN CLRED ONTO THE RWY. THE CAPT COMPLETED HIS PA ANNOUNCEMENT; RETURNED TO THE FREQ; AND CONTINUED TO TAXI PAST THE HOLD SHORT LINE FOR THE RWY. I IMMEDIATELY TOLD HIM TO 'HOLD SHORT;' AND THE CAPT STOPPED THE ACFT JUST BEYOND THE RWY HOLD SHORT LINE. I CONTACTED THE TWR; WHO CLRED US ONTO THE RWY; AND SUBSEQUENTLY CLRED US FOR TKOF. NO CONFLICT OCCURRED; AND THE TWR MADE NO REF TO OUR ERROR. I BELIEVE THAT OUR DESIRE TO GET HOME QUICKLY ON THE FINAL LEG OF OUR TRIP; OUR FAILURE TO EFFECTIVELY COMMUNICATE WITH ONE ANOTHER; OUR DEV FROM ESTABLISHED FLOW PATTERNS AND OUR 'RUSH' TO DEPART CONTRIBUTED TO THIS ERROR.