Date: 201505
Local time of day: 1201-1800
Location: DCA.Airport, DC
Flight conditions: VMC
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
Second aircraft: Bombardier/Canadair Undifferentiated or Other Model
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Human factors: Communication Breakdown
Second reporter function: First Officer; Pilot Not Flying
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR; Ground Incursion Runway
Detector: Person Air Traffic Control
When detected: Taxi
Result: Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: We were taxing out on taxiway J to runway 1 in DCA with a wheels up time in about 7 min. There was a line for runway 1 so we notified Ground control that we could take runway 33. They had us hold short of runway 1 at taxiway G; and we started setting up the aircraft for a runway 33; flap 4; no flex takeoff. Watched one aircraft land and another pull out on to runway 1 to get ready to go. I then heard ground control clear us to cross runway 1; into the box and monitor tower. The first officer repeated the instructions. I activated the exterior lights; we cleared left and right; still looked like the CRJ was waiting and not moving on runway 1 so I started to cross runway 1. As ground control was clearing another aircraft to cross 4; into the box; I could hear someone in the back ground of his mike with a very excited voice. The kind you make when something bad is going to happen and you can't get the words out. I stopped the aircraft immediately; and I think I was already stopped when ground told us to hold short of 1. Noticed that the CRJ that wasn't moving before; now was. We were short of the runway; but still over the line at this point and the CRJ was rejecting its takeoff. After a few seconds; ground had us continue across runway 1 to runway 33; and once there gave us the number for tower with a request to call them when we landed. At this point I still thought we were in the right; and that ground and tower had just gotten there communications crossed. After landing I called DCA tower and spoke with a supervisor.  She had listened to the tape and apparently there was a [same last two digits as our call sign] that ground had cleared to cross runway 4; into the box; and we had taken there clearance. She even said that we read back cross runway 4; not runway 1 that I had heard and the FO remembered saying. I would have sworn under oath that it was our call sign and clearance was given to cross runway 1; but the tapes don't lie.I don't know. I am in and out of DCA all the time. It's one of the airports that you pay a little more attention to; and check and double check. It's busy and doesn't have room for mistakes. I thought we were being careful and doing everything right. I never doubted that were doing exactly what we were supposed to be doing. If the account of the conversations on the tape is as it was relayed to me; then I heard what I was expecting based on what I was seeing around me and knowing the flow of DCA; and not what was actually said.


Second narrative: Original taxi clearance was to taxi to runway 1 via K C (or something similar) hold short runway 4; then shortly thereafter changed to 'taxi runway 1 via J hold short runway 4'. During taxi the flight crew suggested runway 33 if possible. The next clearance was to make the left on G hold short runway 1. We than began configuring the aircraft for a takeoff on runway 33; setting flaps; speeds; deletion of FLEX and adjusting flight plan departure runway/transition. During the hold short of runway 1 at G; we heard a transmission that we thought was '[our call sign] cross runway 1; 4; into the block monitor tower other side.' I; the first officer; read back to the best of my knowledge; 'cross runway 1; 4; into the block tower other side [call sign].' As the captain began to turn on the lights for a runway crossing; another runway cross instruction was given to another airplane that I believed to be [different company similar call sign] cross runway 4 into the block monitor tower. I then glanced over my shoulder noticing a CRJ crossing runway 4; and more importantly an unknown CRJ; appearing to be static in the 'line up and wait' position on runway 1. I even vocally expressed that 'he's holding.' As soon as our aircraft began to cross the hold short line for runway 1 we heard ATC telling us to hold position in a very imperative manner. As the controller was speaking I immediately looked back at the CRJ that was previously on runway 1 and noticed he had begun and already had proceeded to stop his take off roll. I then told ATC that we have already crossed the hold short line. ATC acknowledged and proceeded to instruct us to cross runway 1; 4; into the block monitor tower. In the process we verified again the clearance and proceeded to runway 33. During our line up and wait tower issued us a phone number and instructed us to call when we arrived at our destination. This is the sequence of events as best as I can remember. Verifying to ATC if there is any doubt of any kind especially when crossing active runways/taxi ways. Perhaps not re configuring the aircraft for a different runway (flaps 2 to 4; TO perf changes etc..) during a hold short period when expecting to cross shortly. Query ATC if there is any chance of a misunderstood instruction or unexpected instruction.


Synopsis: EMB-170 flight crew describes the scenario leading up to a runway incursion at DCA.