Scope clauses contained in collective bargaining agreements between major US airlines and pilot unions establish contractual limits on the extent of flying outsourced to regional carriers and the types of aircraft regional partners may operate.
Key restrictions commonly enforced in the US regional market cap regional partner aircraft capacity at 76 seats and set a maximum take-off weight limit of 86,000 pounds. These rules represent contractual agreements negotiated with unions rather than Federal Aviation Administration regulations.
While newer engine technologies improve fuel efficiency, added weight causes modern regional aircraft models such as the Embraer E175-E2 to exceed the 86,000-pound contractual weight threshold, restricting their operational deployment across US regional flight networks.
