This legislation, known as the General Aviation Protection Act or GAP Act, aims to safeguard United States national security by enhancing the review of investments made by foreign adversaries in the critical general aviation sector. It amends the Defense Production Act of 1950 to expand the authority of the Committee on Foreign Investment in the United States (CFIUS), specifically targeting transactions involving "covered general aviation entities" and foreign persons from "countries of concern." These entities include manufacturers of aircraft engines, airframes, avionics, light rotorcraft, and pilot training schools near military installations. The bill mandates CFIUS filings for these covered aviation transactions and extends CFIUS's real estate jurisdiction to include general aviation airports and facilities located near military installations or sensitive airspace. For such real estate transactions involving foreign persons from countries of concern, a rebuttable presumption of national security risk is established. This means the transaction is presumed to pose a risk unless clear and convincing evidence proves otherwise, particularly regarding surveillance capabilities or access to critical infrastructure. A significant provision introduces a rebuttable presumption of prohibition for covered aviation transactions where the acquirer is owned or controlled by a country of concern, is on the NS-CMIC List, or derives substantial income from such a country. Rebutting this presumption requires clear and convincing evidence that the transaction poses no technology transfer risk, has verifiable mitigation measures, and is in the U.S. national security interest. For the highest-risk entities, such as those on the NS-CMIC List or with significant government ownership from a country of concern, mitigation agreements are generally deemed insufficient, requiring a Presidential determination of paramount national security interest for approval. Furthermore, the bill mandates a review and potential reclassification of certain general aviation dual-use technologies, such as high-efficiency engines, advanced composite airframes, and sophisticated avionics, on the Commerce Control List to require export licenses. It also establishes new outbound investment notification requirements for U.S. persons investing in general aviation entities in countries of concern, with some high-risk transactions requiring prior approval from the Department of the Treasury. To address existing vulnerabilities, the legislation directs CFIUS to conduct a comprehensive review of all previously completed transactions involving foreign adversary ownership of covered general aviation entities, assessing the adequacy of existing mitigation measures and recommending divestiture where necessary. Additionally, the FAA Administrator is required to conduct supply chain integrity audits of critical systems (avionics, flight controls, engine controls) from foreign adversary-controlled general aviation certificate holders to detect unauthorized components or vulnerabilities. Finally, the bill prohibits Federal financial assistance, including loans, grants, and contracts, to covered general aviation entities owned or controlled by foreign persons from countries of concern, or those with significant equity or income ties to such countries. It includes a clawback authority for improperly awarded funds and mandates annual certification from entities receiving assistance. Covered general aviation entities are also required to disclose foreign ownership (5% or more equity/voting interest by foreign persons from countries of concern, or 10%+ operating income from country of concern entities) in FAA filings and Federal contract/grant applications, with penalties for non-compliance.