InvestmentsTop Global NewsMarketsReal Estate US Air Force finds additional deficiency in Boeing’s aerial fuel system By financialnews_rlv83x - March 31, 2020 0 62 The U.S. Air Force announced on Monday an additional deficiency in the KC-46 Pegasus aerial fuel system built by Boeing , classifying it at the Category I level, meaning it is a major technical issue that may endanger the aircrew and aircraft.