Sikorsky Aircraft Corp., Stratford, Conn., is being awarded a $21,624,392 modification to a previously awarded indefinite-delivery/indefinite-quantity contract (N00019-07-D-0004) to exercise an option for special progressive aircraft rework for one VH-3D and two VH-60N presidential helicopters, including two months of field level support.  Work will be performed in Stratford, Conn. (99 percent) and Quantico, Va. (1 percent), and is expected to be completed in September 2014.  No funds will be obligated at time of award; funds will be obligated on individual delivery orders as they are issued.  The Naval Air Systems Command, Patuxent River, Md., is the contracting activity.