29 C.F.R. § 1202.12
Under section 205, title II, of the Railway Labor Act, when in the judgment of the National Mediation Board it becomes necessary to establish a permanent national board of adjustment for the air carriers subject to the act to provide for the prompt and orderly settlement of disputes between the employees and the carriers growing out of grievances, or out of the application or interpretation of working agreements, the Board is empowered by its order made, published, and served, to direct the air carriers and labor organizations, national in scope, to select and designate four representatives to constitute a Board known as the National Air Transport Adjustment Board. Two members each shall be selected by the air carriers and the labor organizations of their employees. Up to the present time, it has not been considered necessary to establish the National Air Transport Adjustment Board.
29 C.F.R. § 1202.12