L-3 Communications Vertex Aerospace, LLC, Madison, Miss., is being awarded a $42,285,583 modification to a previously awarded firm-fixed-price, indefinite-delivery requirements contract (N00019-05-D-0023) for logistics support of 124 TH-57B/TH-57C aircraft.  Work will be performed at Naval Air Station (NAS) Whiting Field, Milton, Fla. (99 percent), and NAS Patuxent River, Md. (1 percent), and is expected to be completed in September 2012.  Contract funds will not expire at the end of the current fiscal year.  The Naval Air Systems Command, Patuxent River, Md., is the contracting activity.