Sources Sought TRANSPORTATION, DEPARTMENT OF is conducting a market survey for a repair service contract for ETVS & STVS systems at the FAA Mike Monroney Aeronautical Center in Oklahoma City. The contract involves providing serviceable spare parts and receiving back reparable parts for the Enhanced Terminal Voice Switch (ETVS) and Small Tower Voice Switch (STVS) systems. Northrop Grumman Systems Corporation is currently believed to be the only available source due to their status as the OEM. The FAA is seeking responses from other fully capable and authorized vendors interested in providing the required service. If no other sources are confirmed, the FAA intends to pursue fulfillment of the requirement with Northrop Grumman Systems Corporation using single source procurement procedures. This announcement is for market research purposes.