Narrative:

I was the first officer and PNF on a part 121 scheduled flight for xyz airlines from flagstaff pulman airport, flagstaff, az to phoenix sky harbor airport, phoenix, az. After holding short of runway 21, our flight was cleared into position. A conversation that had begun while holding short of the runway continued for a few moments after I read back the clearance to taxi into position on the runway. We then completed final checklist items before takeoff. I do not recall if the captain confirmed the hold in position clearance to me, as was our usual custom. The captain began to power up the aircraft engines slowly with brakes on, still holding in position, while I monitored the engine instruments. The next thing I heard was the captain state 'set takeoff power' while releasing the brakes and letting the aircraft begin to roll. Then tower said 'xyz, I cleared you into position, continue, you are cleared for takeoff.' we completed the takeoff roll and proceeded without further comment or incident. There was no other traffic at the airport and no further action was required. I feel that the distraction of the last bit of conversation we had as we began our taxi onto the runway and before completion of our checklist was enough to make us have this occurrence. I didn't remember if I got confirmation from the captain on the clearance, and I didn't catch the mistake when he told me to set the takeoff power. Some captain's choose not to turn on all of the aircraft lighting until takeoff clearance is confirmed, as a reminder. In hindsight, I feel like I should have not participated in the conversation's continuance until reaching a more appropriate phase of flight.

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Original NASA ASRS Text

Title: A DH8B CREW STARTED THEIR TKOF ROLL AT FLG WITHOUT A CLRNC.

Narrative: I WAS THE FO AND PNF ON A PART 121 SCHEDULED FLT FOR XYZ AIRLINES FROM FLAGSTAFF PULMAN ARPT, FLAGSTAFF, AZ TO PHOENIX SKY HARBOR ARPT, PHOENIX, AZ. AFTER HOLDING SHORT OF RWY 21, OUR FLT WAS CLRED INTO POS. A CONVERSATION THAT HAD BEGUN WHILE HOLDING SHORT OF THE RWY CONTINUED FOR A FEW MOMENTS AFTER I READ BACK THE CLRNC TO TAXI INTO POS ON THE RWY. WE THEN COMPLETED FINAL CHKLIST ITEMS BEFORE TKOF. I DO NOT RECALL IF THE CAPT CONFIRMED THE HOLD IN POS CLRNC TO ME, AS WAS OUR USUAL CUSTOM. THE CAPT BEGAN TO PWR UP THE ACFT ENGS SLOWLY WITH BRAKES ON, STILL HOLDING IN POS, WHILE I MONITORED THE ENG INSTS. THE NEXT THING I HEARD WAS THE CAPT STATE 'SET TKOF PWR' WHILE RELEASING THE BRAKES AND LETTING THE ACFT BEGIN TO ROLL. THEN TWR SAID 'XYZ, I CLRED YOU INTO POS, CONTINUE, YOU ARE CLRED FOR TKOF.' WE COMPLETED THE TKOF ROLL AND PROCEEDED WITHOUT FURTHER COMMENT OR INCIDENT. THERE WAS NO OTHER TFC AT THE ARPT AND NO FURTHER ACTION WAS REQUIRED. I FEEL THAT THE DISTR OF THE LAST BIT OF CONVERSATION WE HAD AS WE BEGAN OUR TAXI ONTO THE RWY AND BEFORE COMPLETION OF OUR CHKLIST WAS ENOUGH TO MAKE US HAVE THIS OCCURRENCE. I DIDN'T REMEMBER IF I GOT CONFIRMATION FROM THE CAPT ON THE CLRNC, AND I DIDN'T CATCH THE MISTAKE WHEN HE TOLD ME TO SET THE TKOF PWR. SOME CAPT'S CHOOSE NOT TO TURN ON ALL OF THE ACFT LIGHTING UNTIL TKOF CLRNC IS CONFIRMED, AS A REMINDER. IN HINDSIGHT, I FEEL LIKE I SHOULD HAVE NOT PARTICIPATED IN THE CONVERSATION'S CONTINUANCE UNTIL REACHING A MORE APPROPRIATE PHASE OF FLT.

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.