Scope clause
A scope clause is part of a contract between a major airline and the trade union of its pilots that limit the number and size of aircraft that may be flown by the airline's regional airline affiliate. The goal is to protect the union pilots' jobs at the major airline from being outsourced by limiting the regional airlines' passenger capacity. These clauses exist primarily in the United States, Canada, and Mexico. Scope clauses are supported as a means of saving union jobs. Major airline pilots are usually higher paid than regional pilots. There is a perceived safety  advantage in favor of major airlines. Criticism of scope clauses centers on the limits they place on the regional airlines they target. They are seen as a way of artificially maintaining the pay of major airline pilots when regional pilots will in theory fly the same-sized airplanes for less pay. Since 2012, American Airlines, Delta Air Lines and United Airlines cap their regional airlines' jets at 76 seats and a maximum take-off weight (MTOW) at 86,000 lb (39 t). This limit stands until 2019 at United, and 2020 at Delta and American, limiting the sales of the new  Mitsubishi SpaceJet M90 and Embraer 175-E2 to the smaller M100 and current E175. In February 2019, Bombardier launched the CRJ550, a 50-seat variant of its CRJ700. The reduced seating capacity and maximum takeoff weight were specifically designed to comply with scope clauses. United had been pushing to renegotiate the clauses, whereas pilots were arguing against what they see as a "flawed strategy of outsourcing". The decision to reconfigure larger existing models implies that the scope clauses remain frozen. Impact on airlines. Scope clauses place restrictions on how many and what size of aircraft a regional airline may operate . Some holding companies operate a large number of individual airlines, with each airline's fleet specifically tuned to the scope clause of that airline's contracted major carrier. Since 2013, Embraer booked nearly 400 E175 orders in U.S., besting the CRJ900 by over 4 to 1. Delta Air Lines was reported in December 2017 it had maxed out on its 153 allowable 76-seat aircraft, and was forced to fly its 102 70-seaters. The E170 has six less business seats but the E175 has 70 seats, keeping the same premium seats with more range than the E170 or the  CRJ700. SkyWest ordered 30 E175SCs for Delta to enter service in 2018. The E175SC is sold at E170 pricing, a 76-seat retrofit have to go through Embraer. Impact on aircraft manufacturers. Scope clauses have a major influence on manufacturers of regional aircraft. Manufacturers will create airplanes specifically tuned to the scope clauses of most airlines. For this reason and others, regional aircraft tend to be manufactured in families, and competing regional aircraft will often have identical seating capacity. Renegotiation. United Airlines has been renegotiating its agreement with the Air Line Pilots Association (ALPA) after it became amendable on January  31, 2019. , "noneconomic" matters relating to pilot scheduling had been agreed and ALPA expected to start discussion of scope aspects. United is seeking to fly more aircraft in the 76-seat category, given that no manufacturers currently produce 50-seaters. ALPA wishes to tie scope discussions to United's overall fleet, including wide-body aircraft, whereas the current contract links regional restrictions only to the narrow-body fleet size. Any agreement reached with United is expected to set a standard for subsequent negotiations with Delta Air Lines and American Airlines, whose pilot contracts become amendable in December 2019 and in  2020, respectively.