Aerospace mergers and acquisitions plummeted in number and value during the first nine months of 2018 compared to a year ago, according to a new report from PricewaterhouseCoopers. Through September there had been $30.3 billion worth of reported deals, a 49 percent drop from $61.8 billion during the same period in 2017. Deals in North America may continue to decline through the rest of 2018 and into 2019, the report warned, because of ongoing trade disputes between the U.S.