Narrative:

Planned runway 08R for takeoff per ATIS. Pre takeoff data for runway 08R indicated flaps 5. Push back instructions by ramp control indicated a taxi to runway 09L. During engine start (both) and after verifying final weights; I changed the runway in the FMC and sent for takeoff data for runway 09L. Communicating with ground person on the push back was extremely distracting. Sounded like he did not put the microphone mask up to his face as background noise made him almost unreadable. I told him he needed a new headset. After giving disconnect headset; I said to set flaps 5; after start checklist. As we began to taxi; first officer printed and accepted runway 09L takeoff data and even said flaps 1. When we accomplished the before takeoff checklist; I think I said 1 final; 1 indicated green light; touching the flap lever; pointing to FMC takeoff page and comparing to flap indication. I may have said 5 final but somehow did not recognize the difference in the flap handle position versus the FMC takeoff page and flap indicator. During takeoff roll; flap 5 position was noted by the first officer. Speed was about 80 knots. I considered it safer to continue versus reject. Takeoff with flaps 1 V speeds and subsequent flap retraction was uneventful. Bottom line is I miss compared the FMC takeoff page flap setting and the flap indicator along with a flap handle obviously in the wrong position. Not sure if the pushback crew headset distraction had anything to do with my subsequent mindset although it was the worst communication I've experienced between flight deck and push back person. Also not sure why first officer did not advocate to reset flaps to 1 but ultimately it was me who missed the item during the before takeoff checklist.

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Original NASA ASRS Text

Title: B737 flight crew reported a takeoff with the wrong flap setting.

Narrative: Planned Runway 08R for takeoff per ATIS. Pre takeoff data for Runway 08R indicated flaps 5. Push back instructions by ramp control indicated a taxi to Runway 09L. During engine start (both) and after verifying final weights; I changed the runway in the FMC and sent for takeoff data for Runway 09L. Communicating with ground person on the push back was extremely distracting. Sounded like he did not put the microphone mask up to his face as background noise made him almost unreadable. I told him he needed a new headset. After giving disconnect headset; I said to set flaps 5; after start checklist. As we began to taxi; FO printed and accepted Runway 09L takeoff data and even said flaps 1. When we accomplished the before takeoff checklist; I think I said 1 final; 1 indicated green light; touching the flap lever; pointing to FMC takeoff page and comparing to flap indication. I may have said 5 final but somehow did not recognize the difference in the flap handle position versus the FMC takeoff page and flap indicator. During takeoff roll; flap 5 position was noted by the FO. Speed was about 80 knots. I considered it safer to continue versus reject. Takeoff with flaps 1 V speeds and subsequent flap retraction was uneventful. Bottom line is I miss compared the FMC takeoff page flap setting and the flap indicator along with a flap handle obviously in the wrong position. Not sure if the pushback crew headset distraction had anything to do with my subsequent mindset although it was the worst communication I've experienced between flight deck and push back person. Also not sure why FO did not advocate to reset flaps to 1 but ultimately it was me who missed the item during the before takeoff checklist.

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.