Narrative:

Flight had a write up that the previous crew was unable to start the #2 engine in ZZZ. After a 34 minute delay and two engine starts at the gate; we finally were on our way. The number one engine was started normally by first officer (first officer). The number 2 by manual start by captain.we were planning on 18L and we were parked at terminal. We were given 17R which made it a shorter taxi. I; first officer; was heads down changing the fcmu for the change of runway. The close out was tardy; I had to send a request for it. When the closeout arrived; I noticed and voiced that we were 3000 lbs. Heavier than atow (actual takeoff weight) but less than mtow (maximum takeoff weight) with the correct temperature. We were good for toga to (takeoff go around takeoff) and the performance v-speeds. I was still doing a mental check. We did flight controls and the taxi checklist. I was a little behind in changing frequencies from ground to tower. When tower clear us to position and hold. I asked the captain are you good he said he was. I responded position and hold.I was still a little behind because I was still dotting my i's and crossing t's on the [system] in my mind but I thought I will have a moment to catch up on the runway. The captain brought the thrust levers forward and continued for a takeoff roll. I stated 'we were position and hold'. He said: 'no; we were cleared for to (takeoff)' I looked down at the airspeed 40kts. And truthfully; considered that I had missed the last clearance. Before I could say something else tower cleared [us] for takeoff. I repeated the clearance; call 80 and took off uneventfully. I was so busy that I didn't realized how behind and rushed I was until I realized we almost took off without a clearance.

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Original NASA ASRS Text

Title: A321 flight crew reported that takeoff clearance was not issued prior to start of the takeoff roll.

Narrative: Flight had a write up that the previous crew was unable to start the #2 engine in ZZZ. After a 34 minute delay and two engine starts at the gate; we finally were on our way. The number one engine was started normally by FO (First Officer). The number 2 by manual start by Captain.We were planning on 18L and we were parked at terminal. We were given 17R which made it a shorter taxi. I; FO; was heads down changing the FCMU for the change of runway. The close out was tardy; I had to send a request for it. When the closeout arrived; I noticed and voiced that we were 3000 lbs. heavier than ATOW (Actual Takeoff Weight) but less than MTOW (Maximum Takeoff Weight) with the correct temperature. We were good for TOGA TO (Takeoff Go Around Takeoff) and the performance V-speeds. I was still doing a mental check. We did flight controls and the taxi checklist. I was a little behind in changing frequencies from Ground to Tower. When Tower clear us to position and hold. I asked the Captain are you good he said he was. I responded position and hold.I was still a little behind because I was still dotting my i's and crossing t's on the [system] in my mind but I thought I will have a moment to catch up on the runway. The Captain brought the thrust levers forward and continued for a takeoff roll. I stated 'we were position and hold'. He said: 'No; we were cleared for TO (takeoff)' I looked down at the airspeed 40kts. And truthfully; considered that I had missed the last clearance. Before I could say something else Tower cleared [us] for takeoff. I repeated the clearance; call 80 and took off uneventfully. I was so busy that I didn't realized how behind and rushed I was until I realized we almost took off without a clearance.

Data retrieved from NASA's ASRS site 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.