L-3 Communications Vertex Aerospace LLC, Madison, Mississippi, is being awarded an $83,050,682 modification (P00021) to a previously awarded indefinite-delivery requirements contract activity (N00019-13-D-0007) to exercise an option for the organizational and depot level logistics services required to support and maintain the TH-57 fleet. Work will be performed at the Naval Air Station Whiting Field, Milton, Florida, and is expected to be completed in May 2018. No funds are being obligated at time of award; funds will be obligated against individual delivery orders as they are issued. The Naval Air Systems Command, Patuxent River, Maryland, is the contracting.