{"data":{"id":"us/14-cfr-121.431","jurisdiction":"us","citation":"14 CFR 121.431","heading":"Applicability.","body":"(a) This subpart:\n(1) Prescribes crewmember qualifications for all certificate holders except where otherwise specified; and\n(2) Permits training center personnel authorized under part 142 of this chapter who meet the requirements of §§ 121.411 through 121.414 to provide training, testing, and checking under contract or other arrangement to those persons subject to the requirements of this subpart.\n(b) For the purpose of this subpart, the airplane groups and terms and definitions prescribed in § 121.400 and the following definitions apply:\nConsolidation is the process by which a person through practice and practical experience increases proficiency in newly acquired knowledge and skills.\nLine operating flight time is flight time performed in operations under this part.\nOperating cycle is a complete flight segment consisting of a takeoff, climb, enroute portion, descent, and a landing.","path":["Title 14—Aeronautics and Space","CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER G—AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS","PART 121—OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS","Subpart O—Crewmember Qualifications"],"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":"3ddd5c64812667688dac307bc6a8c9b3e02aadd252ca4e8846d896d70f2e18c9","source_id":"us-cfr","stale":true,"prev":"us/14-cfr-121.429","next":"us/14-cfr-121.432"},"notice":"GroundRules: Original legal text. Not legal advice."}