{"data":{"id":"us/14-cfr-25.531","jurisdiction":"us","citation":"14 CFR 25.531","heading":"Hull and main float takeoff condition.","body":"For the wing and its attachment to the hull or main float—\n(a) The aerodynamic wing lift is assumed to be zero; and\n(b) A downward inertia load, corresponding to a load factor computed from the following formula, must be applied:\nwhere—\nn = inertia load factor;\nCTO = empirical seaplane operations factor equal to 0.004;\nVS1 = seaplane stalling speed (knots) at the design takeoff weight with the flaps extended in the appropriate takeoff position;\nβ = angle of dead rise at the main step (degrees); and\nW = design water takeoff weight in pounds.","path":["Title 14—Aeronautics and Space","CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER C—AIRCRAFT","PART 25—AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES","Subpart C—Structure"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-14.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:20Z","sha256":"d5dd67f38718388c831a35eb98cbcb0bf3b2eb4699e3304effe5c61df1259ff5","source_id":"us-cfr","stale":true,"prev":"us/14-cfr-25.529","next":"us/14-cfr-25.533"},"notice":"GroundRules: Original legal text. Not legal advice."}