Narrative:

Mmpr tower cleared our flight for takeoff. We had not had a chance to make our PA for the flight attendants to be seated, as they were still talking on the PA. We advised tower we would need another min. Tower said 'no problem, taxi into position and advise when ready.' I became fixated on the extra lengthy announcement of the flight attendants and was becoming uncomfortable sitting on the runway. Finally the flight attendants finished. We completed all checklist items and commenced our takeoff. Departure was uneventful, with no comments from the tower and no apparent conflicts. We were switched to departure control and the flight proceeded normally. After we were airborne, we realized that we had not received a second takeoff clearance. No mention of this was made by ATC. After analyzing the situation several factors became apparent. 1) I remembered very vividly getting our initial takeoff clearance and that seemed to stay prominent in my mind. 2) I became fixated on the length of the flight attendant's announcement. 3) I was not comfortable sitting on an active runway, especially in mexico. This had an effect of 'we need to get going' syndrome. What I should have done: 1) instead of accepting a 'taxi into position' clearance, I should have requested to hold short of the runway. 2) I should have ignored all that was going on in the back and let the first officer handle all the communication and stayed focused on taxiing the airplane. This was a classic case of having distrs interfere with basic airmanship. Supplemental information from acn 603406: if I had to do it over again I would just tell tower we are not ready yet, we will hold short.

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Original NASA ASRS Text

Title: B737-700 CREW TOOK OFF WITHOUT CLRNC AT MMPR.

Narrative: MMPR TWR CLRED OUR FLT FOR TKOF. WE HAD NOT HAD A CHANCE TO MAKE OUR PA FOR THE FLT ATTENDANTS TO BE SEATED, AS THEY WERE STILL TALKING ON THE PA. WE ADVISED TWR WE WOULD NEED ANOTHER MIN. TWR SAID 'NO PROB, TAXI INTO POS AND ADVISE WHEN READY.' I BECAME FIXATED ON THE EXTRA LENGTHY ANNOUNCEMENT OF THE FLT ATTENDANTS AND WAS BECOMING UNCOMFORTABLE SITTING ON THE RWY. FINALLY THE FLT ATTENDANTS FINISHED. WE COMPLETED ALL CHKLIST ITEMS AND COMMENCED OUR TKOF. DEP WAS UNEVENTFUL, WITH NO COMMENTS FROM THE TWR AND NO APPARENT CONFLICTS. WE WERE SWITCHED TO DEP CTL AND THE FLT PROCEEDED NORMALLY. AFTER WE WERE AIRBORNE, WE REALIZED THAT WE HAD NOT RECEIVED A SECOND TKOF CLRNC. NO MENTION OF THIS WAS MADE BY ATC. AFTER ANALYZING THE SIT SEVERAL FACTORS BECAME APPARENT. 1) I REMEMBERED VERY VIVIDLY GETTING OUR INITIAL TKOF CLRNC AND THAT SEEMED TO STAY PROMINENT IN MY MIND. 2) I BECAME FIXATED ON THE LENGTH OF THE FLT ATTENDANT'S ANNOUNCEMENT. 3) I WAS NOT COMFORTABLE SITTING ON AN ACTIVE RWY, ESPECIALLY IN MEXICO. THIS HAD AN EFFECT OF 'WE NEED TO GET GOING' SYNDROME. WHAT I SHOULD HAVE DONE: 1) INSTEAD OF ACCEPTING A 'TAXI INTO POS' CLRNC, I SHOULD HAVE REQUESTED TO HOLD SHORT OF THE RWY. 2) I SHOULD HAVE IGNORED ALL THAT WAS GOING ON IN THE BACK AND LET THE FO HANDLE ALL THE COM AND STAYED FOCUSED ON TAXIING THE AIRPLANE. THIS WAS A CLASSIC CASE OF HAVING DISTRS INTERFERE WITH BASIC AIRMANSHIP. SUPPLEMENTAL INFO FROM ACN 603406: IF I HAD TO DO IT OVER AGAIN I WOULD JUST TELL TWR WE ARE NOT READY YET, WE WILL HOLD SHORT.

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.