(a) Required Membership of Boards.—Whenever the Secretary of a military department convenes an aircraft accident investigation board to conduct an accident investigation (as described in section 2254(a)(2) of this title) with respect to a Class A accident involving an aircraft under the jurisdiction of the Secretary, the Secretary shall select the membership of the board so that—

(1) a majority of the members (or in the case of a board consisting of a single member, the member) is selected from units other than the mishap unit or a unit subordinate to the mishap unit; and

(2) in the case of a board consisting of more than one member, at least one member of the board is a member of the armed forces or an officer or an employee of the Department of Defense who possesses knowledge and expertise relevant to aircraft accident investigations.

(b) Exception.—The Secretary of the military department concerned may waive the requirement of subsection (a)(1) in the case of an aircraft accident if the Secretary determines that—

(1) it is not practicable to meet the requirement because of—

(A) the remote location of the aircraft accident;

(B) an urgent need to promptly begin the investigation; or

(C) a lack of available persons outside of the mishap unit who have adequate knowledge and expertise regarding the type of aircraft involved in the accident; and

(2) the objectivity and independence of the aircraft accident investigation board will not be compromised.

(c) Consultation Requirement.—In the case of an aircraft accident investigation board consisting of a single member, the member shall consult with a member of the armed forces or an officer or an employee of the Department of Defense who possesses knowledge and expertise relevant to aircraft accident investigations.

(d) Designation of Class A Accidents.—Not later than 60 days after an aircraft accident involving an aircraft under the jurisdiction of the Secretary of a military department, the Secretary shall determine whether the aircraft accident should be designated as a Class A accident for purposes of this section.

(e) Definitions.—In this section:

(1) The term "Class A accident" means an accident involving an aircraft that results in—

(A) the loss of life or permanent disability;

(B) damages to the aircraft, other property, or a combination of both, in an amount in excess of the amount specified by the Secretary of Defense for purposes of determining Class A accidents; or

(C) the destruction of the aircraft.

(2) The term "mishap unit", with respect to an aircraft accident investigation, means the unit of the armed forces (at the squadron or battalion level or equivalent) to which was assigned the flight crew of the aircraft that sustained the accident that is the subject of the investigation.