Narrative:

The ATIS at the gate was reporting a runway xx departure with winds approximately 200@10; a slight quarter tailwind. We loaded the data with these wind conditions and with our data we headed to the runway. Unfortunately during the after start checklist we were slightly thrown off and missed a flaps 4 setting. After the tug disconnect; the first officer did not put the flaps down. In a rush to get them put down during the checklist he put them to flaps 2 and we both agreed they were at 2. I believe this rush made us just assume position 2 as we normally do. I assume with the slight tailwind we were required to use 4; but again we missed this setting. We were just about to takeoff and the tower told a previous aircraft the winds had shifted to a quarter headwind of 240 @10. Luckily with the wind shift we did not suffer too bad of a performance hit; however on the takeoff roll I think we both slowly started to notice the clues that we were a bit off. The V1 speed seemed slow at 118 kts. I again just assumed this was a tailwind penalty. The aircraft did perform well and rotated at what I would consider an acceptable distance. Still; things seemed not that abnormal. Once in the air the first officer slowly brought the nose up and at this point we definitely noticed the speed tape. We didn't get any severe indications of stall; but it was apparent something was off. After takeoff we made a few comments to each other about the speed tape. I pulled up the takeoff data and immediately saw the flaps 4 setting right there on the page. I can certainly say this is a first for me. I do not normally miss the flap setting. I do believe this was all caused by us fixating on the flaps not being down during the checklist and then quickly just selecting 2. I've always tried not to be complacent while saying these numbers but it failed me this time by just saying 'two.' this could have been prevented by simply not rushing through the after takeoff checklist; and not fixating on the flaps not being down yet.

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Original NASA ASRS Text

Title: ERJ-175 flight crew reported mistakenly taking off with flaps set at two instead of the computed requirement of flaps four.

Narrative: The ATIS at the gate was reporting a Runway XX departure with winds approximately 200@10; a slight quarter tailwind. We loaded the data with these wind conditions and with our data we headed to the runway. Unfortunately during the after start checklist we were slightly thrown off and missed a flaps 4 setting. After the tug disconnect; the FO did not put the flaps down. In a rush to get them put down during the checklist he put them to flaps 2 and we both agreed they were at 2. I believe this rush made us just assume position 2 as we normally do. I assume with the slight tailwind we were required to use 4; but again we missed this setting. We were just about to takeoff and the Tower told a previous aircraft the winds had shifted to a quarter headwind of 240 @10. Luckily with the wind shift we did not suffer too bad of a performance hit; however on the takeoff roll I think we both slowly started to notice the clues that we were a bit off. The V1 speed seemed slow at 118 kts. I again just assumed this was a tailwind penalty. The aircraft did perform well and rotated at what I would consider an acceptable distance. Still; things seemed not that abnormal. Once in the air the First Officer slowly brought the nose up and at this point we definitely noticed the speed tape. We didn't get any severe indications of stall; but it was apparent something was off. After takeoff we made a few comments to each other about the speed tape. I pulled up the takeoff data and immediately saw the flaps 4 setting right there on the page. I can certainly say this is a first for me. I do not normally miss the flap setting. I do believe this was all caused by us fixating on the flaps not being down during the checklist and then quickly just selecting 2. I've always tried not to be complacent while saying these numbers but it failed me this time by just saying 'TWO.' This could have been prevented by simply not rushing through the After Takeoff checklist; and not fixating on the flaps not being down yet.

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.