News Brief: The U.S. Air Force today awarded Boeing a $2.9 billion contract for 18 more KC-46A tanker aircraft and associated equipment, bringing the total number of tankers on contract to 52. The report comes as Boeing is preparing to make its first deliveries of the 767-based aircraft, which are being built at the company’s plant in Everett, Wash. Last week, the KC-46A program completed the Federal Aviation Administration’s certification process. Deliveries are set to begin in October, but in today’s news release, Boeing said only that the first deliveries were expected “later this year.” Eventually, the Air Force’s KC-46 order is expected to amount to 179 planes. Boeing has had to absorb more than $3 billion in pre-tax cost overruns, due to complications that cropped up in the fixed-price, $44.4 billion deal.