Narrative:

Captain called for 'before takeoff' checklist while approaching runway. I began checklist by briefing passenger over the PA system which cuts me out from hearing ATC instructions. When finished with my briefing, captain said 'here's the squawk code' and then called for 'boxed items' (final before takeoff checklist items). I completed the checklist while captain taxied on to runway. He then asked me if I was ready to go and I responded by saying 'yes.' captain advanced power levers for takeoff and we began the takeoff roll. Shortly thereafter I said 'we have been cleared for takeoff?' at which time tower said over the radio 'air carrier X, position and hold!' upon hearing this, we aborted takeoff and then consequently returned for takeoff. Problem arose while I was briefing passenger over PA. I could not hear ATC speaking to captain and when I came back on, I was out of the loop temporarily until I asked captain 'we have been cleared for takeoff?' on the roll. Then we aborted. Supplemental information from acn 348645: I misread position and hold clearance for takeoff clearance. I started takeoff roll, then quickly realized error and aborted takeoff, got clearance from tower for a 180 degree turn to taxi back for takeoff again.

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Original NASA ASRS Text

Title: AN SF-340 CREW STARTED ITS TKOF ROLL BEFORE BEING CLRED. TKOF ABORTED WHEN FO REALIZED THAT A MISTAKE MAY HAVE BEEN MADE. ERROR ADMITTED.

Narrative: CAPT CALLED FOR 'BEFORE TKOF' CHKLIST WHILE APCHING RWY. I BEGAN CHKLIST BY BRIEFING PAX OVER THE PA SYS WHICH CUTS ME OUT FROM HEARING ATC INSTRUCTIONS. WHEN FINISHED WITH MY BRIEFING, CAPT SAID 'HERE'S THE SQUAWK CODE' AND THEN CALLED FOR 'BOXED ITEMS' (FINAL BEFORE TKOF CHKLIST ITEMS). I COMPLETED THE CHKLIST WHILE CAPT TAXIED ON TO RWY. HE THEN ASKED ME IF I WAS READY TO GO AND I RESPONDED BY SAYING 'YES.' CAPT ADVANCED PWR LEVERS FOR TKOF AND WE BEGAN THE TKOF ROLL. SHORTLY THEREAFTER I SAID 'WE HAVE BEEN CLRED FOR TKOF?' AT WHICH TIME TWR SAID OVER THE RADIO 'ACR X, POS AND HOLD!' UPON HEARING THIS, WE ABORTED TKOF AND THEN CONSEQUENTLY RETURNED FOR TKOF. PROB AROSE WHILE I WAS BRIEFING PAX OVER PA. I COULD NOT HEAR ATC SPEAKING TO CAPT AND WHEN I CAME BACK ON, I WAS OUT OF THE LOOP TEMPORARILY UNTIL I ASKED CAPT 'WE HAVE BEEN CLRED FOR TKOF?' ON THE ROLL. THEN WE ABORTED. SUPPLEMENTAL INFO FROM ACN 348645: I MISREAD POS AND HOLD CLRNC FOR TKOF CLRNC. I STARTED TKOF ROLL, THEN QUICKLY REALIZED ERROR AND ABORTED TKOF, GOT CLRNC FROM TWR FOR A 180 DEG TURN TO TAXI BACK FOR TKOF AGAIN.

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.