The Scope Clause is Numero Uno in a contract. It defines the "scope" or the parameters of the contract. The scope usually states who will do the flying (all members of the bargaining unit), what restrictions will be imposed on the company for code-sharing, commuter affiliations, and other restrictions. At E.A.Stern (Eastern Airlines) the scope said all flying under the Eastern name and under the corporation called Eastern would be flown by members of the Eastern pilots. That way the company could not set under an "alter ego" with non-union pilots. If Eastern set up Eastern II and it was owned by any entity owned by Eastern shareholders, the flying would have to done by Eastern seniority list pilots. Without a scope clause, the company can sub-contract out flying to another flight operation.
The idea of a a scope clause is under attack in the present economy, what with code-sharing, regional jets and "low-cost" subsidiary lines.