under this section and may not be utilized for other programs or purposes. (3) Subject to operating agreement The loan guarantee under paragraph (1) shall be subject to the operating agreement entered into under subsection (b)(3). (4) Use of funds Obligations incurred by the Under Secretary under this paragraph shall be subject to the availability of funds provided in advance specifically for the purpose of such loan guarantees. (e) Phased implementation schedule and required reports and briefings The program established under subsection (a) shall be carried out in two phases as follows: (1) Phase 1 (A) In general Phase 1 shall consist of an initial pilot program with one public-private partnership, consistent with subsection (b), to assess the feasibility and advisability of expanding the scope of the program. The Under Secretary shall begin implementation of phase 1 not later than 180 days after the date of the enactment of this Act. (B) Implementation schedule and framework Not later than 90 days after the date of the enactment of this Act, the Secretary shall submit an implementation plan to the congressional defense committees on the design of phase 1. The plan shall include— (i) an overview of, and the activities undertaken, to execute the public-private partnership