This synopsis is to notify industry of the Government's intent to establish a 5-year Requirements contract for the repair of the M61A1 20mm Hydraulic Drive (HyDrive). This item is critical for the sustainment of the 20mm M61A1 Gatling gun weapon system on the F-16 fighter aircraft. The contract will consist of a 12-month base ordering period and four (4) 12-month ordering periods. The Hydrive, consisting of a control valve and a motor, provides the mechanical power to operate the Gatling gun. The required service is the inspection, evaluation, repair, and testing of this component. National Stock Number (NSN): 1005-01-061-8335 Part Number: 217F429 Estimated Quantities: Best Estimated Quantity (BEQ) of 20 each for each of the five ordering periods. . The proposed contract action will be competed among a limited number of responsible sources under the authority of FAR 6.302-1, "Only One or a Limited Number of Responsible Sources and No Other Supplies or Services Will Satisfy Agency Requirements." Market research has concluded that only a limited number of sources possess the requisite capabilities for this repair. The Government does not have the technical data package that would enable a full and open competition. Instructions to Interested Parties: The solicitation is anticipated to be issued on or around 2 Mar 2026, with proposals due approximately 45 days later. The formal Request for Proposal (RFP) will be issued directly to the sources identified during market research. All potential offerors should contract the PCO/Buyer for additional information.