(a) Composition The Board shall have an Executive Board composed of - (1) the chairman of the Board; (2) the vice chairman of the Board; (3) the secretary of the Board; (4) the treasurer of the Board; and (5) an at-large member of the Board elected by the Board at its initial meeting. (b) Vacancies In the case of any vacancy which occurs in the position of at-large member before the expiration of such member's term, the Board shall elect a replacement to complete that term. (c) Meetings The Executive Board shall hold not more than 4 regular meetings per calendar year. Special meetings may be held upon the call of the chairman or 3 members of the Executive Board. (d) Quorum A majority of the Executive Board shall constitute a quorum. (e) Powers The Executive Board may hold and use all the powers of the Board, subject to the approval of the Board.