Narrative:

It was the start of a 6 leg day. And it was the first time I had flown with the captain. It was determined that I would fly the first 2 legs to twin falls, identification, and the return leg to salt lake city. For reasons I could not determine, the captain seemed rushed and missed multiple radio calls. After landing at twin falls, the controls were xferred to the captain and he asked for the after landing check. I no sooner looked down to perform the check when the captain realized we were about to go off the taxiway and applied full right tiller steering to avoid going off. Once I realized what was happening, I could tell the captain had been preoccupied with the fuel gauges rather than looking outside. This certainly flustered me, and should have acted as a red flag. However, the reason for this report occurred during takeoff from twin falls. The wind was calm and the captain wanted to depart runway 7. Using this runway requires a back taxi for full length. The taxi out was normal with all the appropriate checks completed. Back taxiing on the runway, the captain asked me to perform the before takeoff check which entails using the cockpit to cabin interphone to talk to the flight attendant to see if they are ready. Just before leaving communication #1 to talk to the flight attendant, I heard the captain tell tower we were ready to go. I then heard tower clear us for takeoff at the end. After talking with the flight attendant, she told me she was not ready, which I then told the captain. I told tower we would pull off at the end in the turn-around area. Tower then cleared us to remain in position and hold on the runway and advise when ready to go. I acknowledged the tower's instructions and the captain again asked me to call the flight attendant, which I did, to find her ready to go. I told the captain she was ready and he said something to the effect of 'let's get going, you have the flight controls.' I advanced the power and departed. Once airborne, tower informed us we had not been cleared for takeoff. I attribute this breakdown in CRM to being rushed and assuming the captain had received a takeoff clearance when he said 'let's get going, you have the flight controls.' the captain told me he took full responsibility for the situation. However, I feel I share the blame, since I knew I was off frequency at a crucial time and could have simply have asked 'are we cleared for takeoff?'

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Original NASA ASRS Text

Title: UNAUTH TKOF BY AN EMB120 FLC AT TWF, ID.

Narrative: IT WAS THE START OF A 6 LEG DAY. AND IT WAS THE FIRST TIME I HAD FLOWN WITH THE CAPT. IT WAS DETERMINED THAT I WOULD FLY THE FIRST 2 LEGS TO TWIN FALLS, ID, AND THE RETURN LEG TO SALT LAKE CITY. FOR REASONS I COULD NOT DETERMINE, THE CAPT SEEMED RUSHED AND MISSED MULTIPLE RADIO CALLS. AFTER LNDG AT TWIN FALLS, THE CTLS WERE XFERRED TO THE CAPT AND HE ASKED FOR THE AFTER LNDG CHK. I NO SOONER LOOKED DOWN TO PERFORM THE CHK WHEN THE CAPT REALIZED WE WERE ABOUT TO GO OFF THE TXWY AND APPLIED FULL R TILLER STEERING TO AVOID GOING OFF. ONCE I REALIZED WHAT WAS HAPPENING, I COULD TELL THE CAPT HAD BEEN PREOCCUPIED WITH THE FUEL GAUGES RATHER THAN LOOKING OUTSIDE. THIS CERTAINLY FLUSTERED ME, AND SHOULD HAVE ACTED AS A RED FLAG. HOWEVER, THE REASON FOR THIS RPT OCCURRED DURING TKOF FROM TWIN FALLS. THE WIND WAS CALM AND THE CAPT WANTED TO DEPART RWY 7. USING THIS RWY REQUIRES A BACK TAXI FOR FULL LENGTH. THE TAXI OUT WAS NORMAL WITH ALL THE APPROPRIATE CHKS COMPLETED. BACK TAXIING ON THE RWY, THE CAPT ASKED ME TO PERFORM THE BEFORE TKOF CHK WHICH ENTAILS USING THE COCKPIT TO CABIN INTERPHONE TO TALK TO THE FLT ATTENDANT TO SEE IF THEY ARE READY. JUST BEFORE LEAVING COM #1 TO TALK TO THE FLT ATTENDANT, I HEARD THE CAPT TELL TWR WE WERE READY TO GO. I THEN HEARD TWR CLR US FOR TKOF AT THE END. AFTER TALKING WITH THE FLT ATTENDANT, SHE TOLD ME SHE WAS NOT READY, WHICH I THEN TOLD THE CAPT. I TOLD TWR WE WOULD PULL OFF AT THE END IN THE TURN-AROUND AREA. TWR THEN CLRED US TO REMAIN IN POS AND HOLD ON THE RWY AND ADVISE WHEN READY TO GO. I ACKNOWLEDGED THE TWR'S INSTRUCTIONS AND THE CAPT AGAIN ASKED ME TO CALL THE FLT ATTENDANT, WHICH I DID, TO FIND HER READY TO GO. I TOLD THE CAPT SHE WAS READY AND HE SAID SOMETHING TO THE EFFECT OF 'LET'S GET GOING, YOU HAVE THE FLT CTLS.' I ADVANCED THE PWR AND DEPARTED. ONCE AIRBORNE, TWR INFORMED US WE HAD NOT BEEN CLRED FOR TKOF. I ATTRIBUTE THIS BREAKDOWN IN CRM TO BEING RUSHED AND ASSUMING THE CAPT HAD RECEIVED A TKOF CLRNC WHEN HE SAID 'LET'S GET GOING, YOU HAVE THE FLT CTLS.' THE CAPT TOLD ME HE TOOK FULL RESPONSIBILITY FOR THE SIT. HOWEVER, I FEEL I SHARE THE BLAME, SINCE I KNEW I WAS OFF FREQ AT A CRUCIAL TIME AND COULD HAVE SIMPLY HAVE ASKED 'ARE WE 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.