; and (B) using funds made available for fiscal year 2024 or a subsequent fiscal year for the procurement of F–35 aircraft. 226. F–35 propulsion and thermal management modernization program (a) Establishment and validation of requirements The Secretary of the Air Force (with respect to F–35A aircraft of the Air Force) and the Secretary of the Navy (with respect to F–35B and F–35C aircraft of the Navy and the Marine Corps) shall each— (1) establish requirements for the propulsion, power and cooling, thermal management, and electrical power systems of the F–35 aircraft system that adequately support the planned service-life and all planned mission systems hardware and software capability upgrades for such aircraft system; (2) validate the requirements