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                  From the grind and pop of retracting landing gear after
                  takeoff, to the incessant whoosh of air conditioning
                  mid-flight, to the hydraulic moan of wing flaps extended
                  before landing, it's clear that much goes on unseen beneath
                  the floorboards, above the ceiling panels, and elsewhere in
                  the guts of a modern passenger jet. In this interactive, look
                  beneath the skin of a late-model Boeing 737, the most widely
                  flown commercial jetliner of all time, and explore a cutaway
                  detailing the 12 major systems that make it tick. To launch
                  the interactive, click
                  on the image at left.—Lexi Krock
                 
                
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