Narrative:

Issues [were] thunderstorms (trw); reroutes; significant load closeout delay; adjustment of minimum takeoff fuel with dispatch; [and] belligerent passenger during climb out. Departed with trws [in] all quadrants except takeoff departure path. Requested flight attendants to remain seated until I call them because of weather. After sterile chime; climbing through 11;000 ft; [with] seatbelt sign on; #1 flight attendant called flightdeck [and] asked that I make PA for passengers to remain seated. [He/she] said one first class passenger came to them several times angrily requesting service. First officer [was] flying [and] weaving around weather with assistance from ATC and radar. Level at 17;000 ft [with] autopilot on in heading select mode. We planned for FL240 and ATC said FL220 would be our final [altitude]. ATC cleared us to climb from 17;000 ft to FL220. I set FL220 in altitude MCP window and received acknowledgment from the first officer for FL220. Still dealing with passenger issue in first class; monitoring flight progress; listening to ATC in back ground; while talking to #1 flight attendant. First officer was doing a good job deviating around weather. I did not notice first officer grab the altitude selector knob instead of heading select knob to try to turn the aircraft further right around weather. He was looking outside as we were between circuit breaker cells. He realized the aircraft was not turning and he looked at MCP and saw 241 in altitude window. Realizing what he had done he reset 240 instead of 220 back in altitude window. He had FL240 on the brain because we were filed for FL240. We were both task-saturated at this point dealing with all issues [stated above]. I rejoined first officer after passenger issue and normal checklist completion and we were approaching FL220. I noticed we didn't get our 900 ft prior illumination on our altimeters and looked at altitude window and saw 24;000 ft displayed. I asked the first officer if we had been given FL240; he didn't answer. As we climbed through FL220 at approximately 500 FPM; I said to level at 220! The first officer turned off autopilot and descended from 22;250 ft back to FL220. Turned autopilot back on and we remained at FL220. I asked him why 24;000 ft was in the altitude window. We were so busy we had to put that behind us and complete our mission of flying the aircraft to a safe landing. We broke out of weather about 150 miles from our destination and landed the aircraft uneventfully. Later that day we sat down and discussed the altitude issue again; confirming his inadvertent setting of altitude instead of heading. This brings to mind; why are these knobs the same shape? And what happened to the flight engineer?

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Original NASA ASRS Text

Title: While the Captain coordinated with a Flight Attendant about an unruly passenger; the distracted First Officer turned the B737-800's altitude set window to FL240 instead of selecting heading 240 to deviate around weather; overshooting the assigned FL220 by 250 FT.

Narrative: Issues [were] thunderstorms (TRW); reroutes; significant load closeout delay; adjustment of minimum takeoff fuel with Dispatch; [and] belligerent passenger during climb out. Departed with TRWs [in] all quadrants except takeoff departure path. Requested flight attendants to remain seated until I call them because of weather. After sterile chime; climbing through 11;000 FT; [with] seatbelt sign on; #1 Flight Attendant called flightdeck [and] asked that I make PA for passengers to remain seated. [He/she] said one first class passenger came to them several times angrily requesting service. First Officer [was] flying [and] weaving around weather with assistance from ATC and RADAR. Level at 17;000 FT [with] autopilot on in heading select mode. We planned for FL240 and ATC said FL220 would be our final [altitude]. ATC cleared us to climb from 17;000 FT to FL220. I set FL220 in altitude MCP window and received acknowledgment from the First Officer for FL220. Still dealing with passenger issue in first class; monitoring flight progress; listening to ATC in back ground; while talking to #1 Flight Attendant. First Officer was doing a good job deviating around weather. I did not notice First Officer grab the altitude selector knob instead of heading select knob to try to turn the aircraft further right around weather. He was looking outside as we were between CB cells. He realized the aircraft was not turning and he looked at MCP and saw 241 in altitude window. Realizing what he had done he reset 240 instead of 220 back in altitude window. He had FL240 on the brain because we were filed for FL240. We were both task-saturated at this point dealing with all issues [stated above]. I rejoined First Officer after passenger issue and normal checklist completion and we were approaching FL220. I noticed we didn't get our 900 FT prior illumination on our altimeters and looked at altitude window and saw 24;000 FT displayed. I asked the First Officer if we had been given FL240; he didn't answer. As we climbed through FL220 at approximately 500 FPM; I said to level at 220! The First Officer turned off autopilot and descended from 22;250 FT back to FL220. Turned autopilot back on and we remained at FL220. I asked him why 24;000 FT was in the altitude window. We were so busy we had to put that behind us and complete our mission of flying the aircraft to a safe landing. We broke out of weather about 150 miles from our destination and landed the aircraft uneventfully. Later that day we sat down and discussed the altitude issue again; confirming his inadvertent setting of altitude instead of heading. This brings to mind; why are these knobs the same shape? And what happened to the flight engineer?

Data retrieved from NASA's ASRS site as of April 2012 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.