...the agreement or the date on which the agreement became subject to modification under subsection (a) of this section, or if the parties decide upon arbitration...the procedures therefor, an arbitration board shall l>e established consisting of 3 members, not members of the factfinding panel, 1 of whom shall be selected...

...the agreement or the date on which the agreement became subject to modification under sulisection (a) dispute arises involving an interpretation of the nward. the division of t u]ion the procedures therefor, an arbitration board shall lie established consisting of •( member-,...

...to arbitration. "(3) ARBITRATION BOARD — to modification under paragraph (1) of this subsection, or if the parties decide upon arbitration but do not...shall be selected by the Airports Authority, 1 by the bargaining representative, and the third by the 2 thus selected who shall be designated chairman....

...the agreement or the date on which the agreement became subject to modification under subsection (a) of this section, or if the parties decide upon arbitration...board shall be established consisting of 3 members, not members of the factfinding panel, 1 of whom shall be selected by the Postal Service, 1 by the bargaining...