pluem05/iStock via Getty Images The air cargo market has had some sharp ups and downs since I last covered Air Transport Services Group (NASDAQ:ATSG), and honestly, there’s been more downs than ups. While companies throughout the logistics chain scrambled to add capacity as air cargo demand soared (in part due to a major step up in e-commerce, also in part due to limitations on other carriage types), those additions overshot the mark and end-customer demand weakness has compounded that issue. Air Transp ...