THIS SYNOPSIS IS FOR INFORMATIONAL PURPOSES ONLY AND NOT A REQUEST FOR COMPETITIVE PROPOSALS.  The Naval Air Systems Command, E-2/C-2 Airborne Tactical Data System Program Office (PMA-231), Patuxent River, MD intends to award a sole-source modification to N00019-13-C-9999 with Northrop Grumman Systems Corporation (NGSC), 2000 W. NASA Blvd., Melbourne FL, 32904.  The purpose of this effort is to procure all labor and material necessary to incorporate NFS-2 RSM Part Number ECP 91145/E2/1205-16 and IFF Mode 5 Interrogator ECP PMA231-E2D-01-17.