Narrative:

Taxiing out for takeoff on runway 19 at dca. I switched over to talk to passenger. Captain was crossing hold line onto runway 19 when I switched back. I asked if we were cleared and he stated we were cleared for takeoff. Tower told us to make a 180 degrees and hold short. A different airplane (same company) had been cleared for takeoff on runway 15 and my captain thought it was for us. A contributing factor was another aircraft ahead of us was told to pull aside because we would be going out first.

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Original NASA ASRS Text

Title: EMB145 FLT CREW HAS RWY INCURSION AT DCA.

Narrative: TAXIING OUT FOR TKOF ON RWY 19 AT DCA. I SWITCHED OVER TO TALK TO PAX. CAPT WAS XING HOLD LINE ONTO RWY 19 WHEN I SWITCHED BACK. I ASKED IF WE WERE CLRED AND HE STATED WE WERE CLRED FOR TKOF. TWR TOLD US TO MAKE A 180 DEGS AND HOLD SHORT. A DIFFERENT AIRPLANE (SAME COMPANY) HAD BEEN CLRED FOR TKOF ON RWY 15 AND MY CAPT THOUGHT IT WAS FOR US. A CONTRIBUTING FACTOR WAS ANOTHER ACFT AHEAD OF US WAS TOLD TO PULL ASIDE BECAUSE WE WOULD BE GOING OUT FIRST.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.