Narrative:

As PNF, I acknowledged the clearance to taxi into position and hold on runway 3 at dca. The first officer called for the final items of the before takeoff checklist, and when completed, I switched off tower to give a final briefing to the passenger. This is normally done before taxiing onto the runway, but I did not have time. (This briefing is just a reminder to check seatbelts and make sure carry on items are stowed.) when I switched back to tower, the first officer said 'let's go.' I asked him if we were cleared, and he said yes. So, I turned on the lights and we initiated the takeoff roll. The local controller noticed us moving and at first he used the wrong call sign, but I knew he meant us. I initiated the abort, and we stopped short of runway 36, which was also active. We taxied back to the beginning of the runway and departed normally a couple mins later, with proper clearance. The problem arose because I did not hear a clearance for takeoff myself. The first officer thought that when instructed to 'taxi into position and hold' we were cleared for takeoff. Complacency was a factor on my part. I should have confirmed with tower that we were cleared for takeoff.

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Original NASA ASRS Text

Title: FO MISUNDERSTOOD CLRNC AND STARTED TKOF ROLL BEFORE BEING CLRED BY TWR. CAPT SUBSEQUENTLY ABORTED TKOF.

Narrative: AS PNF, I ACKNOWLEDGED THE CLRNC TO TAXI INTO POS AND HOLD ON RWY 3 AT DCA. THE FO CALLED FOR THE FINAL ITEMS OF THE BEFORE TKOF CHKLIST, AND WHEN COMPLETED, I SWITCHED OFF TWR TO GIVE A FINAL BRIEFING TO THE PAX. THIS IS NORMALLY DONE BEFORE TAXIING ONTO THE RWY, BUT I DID NOT HAVE TIME. (THIS BRIEFING IS JUST A REMINDER TO CHK SEATBELTS AND MAKE SURE CARRY ON ITEMS ARE STOWED.) WHEN I SWITCHED BACK TO TWR, THE FO SAID 'LET'S GO.' I ASKED HIM IF WE WERE CLRED, AND HE SAID YES. SO, I TURNED ON THE LIGHTS AND WE INITIATED THE TKOF ROLL. THE LCL CTLR NOTICED US MOVING AND AT FIRST HE USED THE WRONG CALL SIGN, BUT I KNEW HE MEANT US. I INITIATED THE ABORT, AND WE STOPPED SHORT OF RWY 36, WHICH WAS ALSO ACTIVE. WE TAXIED BACK TO THE BEGINNING OF THE RWY AND DEPARTED NORMALLY A COUPLE MINS LATER, WITH PROPER CLRNC. THE PROB AROSE BECAUSE I DID NOT HEAR A CLRNC FOR TKOF MYSELF. THE FO THOUGHT THAT WHEN INSTRUCTED TO 'TAXI INTO POS AND HOLD' WE WERE CLRED FOR TKOF. COMPLACENCY WAS A FACTOR ON MY PART. I SHOULD HAVE CONFIRMED WITH TWR THAT WE WERE CLRED FOR TKOF.

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.