The Boeing 737-600 is a narrow-body airliner and a variant of the 737 Next Generation series. This variant, like other 737s in the Next Generation series, features upgraded engines and overall improvements however it's fuselage is almost exactly the same of the Boeing 737-500 making it possible for it to be a like-for-like replacement for that variant from the Classic series. The Boeing 737-600 is the shortest variant and the least produced in the Next Generation series. Despite the overall grand success of the Next Generation series, the Boeing 737-600 variant did not see the large orders that its -700 & -800 sister variants saw and due to that lack of interest, this variant was the first to be cut from production. The Boeing 737-600 typically flies short to medium haul flights that have medium demand. It can also be used as a 'shuttle' between city centers given it's lower passenger capacity however like the -500 variant it replaced, it is also well suited to fly longer or thinner routes where the demand is not as high.