Editor's note: This story was updated at 3:30 p.m. on Jan. 29 to include new information from the Navy's official notification to Congress. Navy Secretary Donald Winter notified Congress yesterday that the VH-71 presidential helicopter program has breached a congressionally mandated cost threshold, giving the Obama administration the choice of paying billions more for the aircraft or killing the program outright. The announcement was not unexpected for the troubled helicopter, built by a Lockheed Martin and AgustaWestland partnership. Pentagon acquisition...