The Pentagon official responsible for evaluating design maturity of new weapon systems says numerous delays by Boeing in manufacturing a prototype KC-46 aerial refueling tanker aircraft threaten to hamper the Air Force's planned schedule for key production decisions for the $49 billion program. C. David Brown, deputy assistant secretary of defense for developmental testing and evaluation, in an annual report to Congress said delays stemming from problems with wiring the Boeing 767-2C -- a precursor to the KC-46 -- threaten...