Date: 202105
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B737 MAX Series Undifferentiated
Operator: Air Carrier
Flight phase: Takeoff / Launch
Aircraft component: Flap Control (Trailing & Leading Edge)
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Distraction; Workload; Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown; Ground Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: Departing ZZZ in a 737 MAX. Planned TO data was flaps 1 reduced. We had briefed a gusty wind TO procedure utilizing full power; reduced speeds and VR max as we were holding short of the runway. Previous departures on our RNAV SID we getting headings on departure for weather. As we took the runway; we could see weather in our departure route and anticipated a heading too. We sat in position for a few minutes before ATC announced a 5 minute stop on departures to sort out the previous departures. I suggested to FO see if we can get Flap 5 data and do the same full power; reduced speed; VR max procedure with flaps 5; if time permitted. He agreed. We ordered data then I made a very brief PA about a temporary stop on departures; but we would be airborne shortly; please stay seated.The data came up and I announced the new speeds to include VR max and FO loaded it. My intention was to run a new before Takeoff checklist to clean it up and be ready to go. At this time; a FA called to ask if someone could use the restroom to which I said no. Then ATC called 2 or 3 different time to inquire about a desired heading on departure. The stop was then lifted and we departed. Upon reaching acceleration altitude the FO realized we were still at flaps 1 when he was looking to clean up. At that point I realized I had failed in following up on the before Takeoff checklist.The takeoff itself was uneventful with no more than light chop and moderate rain during initial climb. We debriefed our error for the next hour and a half on our way to ZZZ1. I clearly had failed in letting the distractions take my focus off of the checklist. The weather itself was just a rain shower with no gusts; no wind shear; no lightning and our fancy MAX radar didn't show any of the severe weather cues that it is capable of showing. My FO had told me he had flown very little during the pandemic so my flaps 1 vs 5 concern was more related to his recent experience that to the weather.Another threat was the MAX. We don't get to fly them that often (yet) and I find my eyes are 'lost' when trying to scan the gauges that have always been in the same place for the last XX+ years. Now; many of them have moved. The flap indicator was not where it normally is. That may have caught my attention before accepting a takeoff clearance in an NG.Fortunately for us we were utilizing VR max procedures as this gave us additional speed over and above the flap 1 speeds. Our flaps 5 VR max was 167 which was 8 knots higher than our flaps 1 VR of 159. The tail strike potential of utilizing the published flaps 5 speed on a reduced takeoff with flaps 1 selected is very clear to me. I will no longer be doing flaps 1 takeoffs in [other make/model] airplanes.  Most FOs ask me about my flap preferences for takeoff. I gather many captains don't do flaps 1 in the bigger airplanes.




Synopsis: B737 MAX Captain reported realizing after departure that they had not changed the takeoff flaps setting as discussed before takeoff. Pilot reported as contributing factors several interruptions and a different gauge scan because the flap indicator on the B737 MAX aircraft is in a different position than on an NG.