PART 39--AIRWORTHINESS DIRECTIVES Subpart A--General Sec. 39.1 Applicability. 39.3 General. Subpart B--Airworthiness Directives 39.11 Applicability. 39.13 Airworthiness directives. Authority: Secs. 601 and 603, 72 Stat. 775, 776; 49 U.S.C. 1421, 1423. Source: Docket No. 5061, 29 FR 14403, Oct. 20, 1964, unless otherwise noted. Subpart A--General Sec. 39.1 Applicability. This part prescribes airworthiness directives that apply to aircraft, aircraft engines, propellers, or appliances (hereinafter referred to in this part as "products") when-- (a) An unsafe condition exists in a product; and (b) That condition is likely to exist or develop in other products of the same type design. [Doc. No. 5061, 29 FR 14403, Oct. 20, 1964, as amended by Amdt. 39-106, 30 FR 8826, July 14, 1965] Sec. 39.3 General. No person may operate a product to which an airworthiness directive applies except in accordance with the requirements of that airworthiness directive. Subpart B--Airworthiness Directives Sec. 39.11 Applicability. This subpart identifies those products in which the Administrator has found an unsafe condition as described in Sec. 39.1 and, as appropriate, prescribes inspections and the conditions and limitations, if any, under which those products may continue to be operated. Sec. 39.13 Airworthiness directives. All airworthiness directives contained in Sec. 507.10 of the regulations of the Administrator are hereby transferred to this section of the Federal Aviation Regulations. Editorial Note: Airworthiness directives prescribed under this subpart were published in full in the Federal Register at 21 FR 9449, Dec. 4, 1956. For Federal Register citations to amendments in 1957 and subsequent years, see former Sec. 507.10 of this title, in a separate volume entitled "List of Sections Affected 1949-1963." See also Sec. 39.13 in a separate volume entitled "List of CFR Sections Affected, 1964-1972," and the List of CFR Sections Affected at the end of this volume.