MetroJet was a no-frills airline brand operated as a wholly owned division of US Airways from 1998 until 2001.

A low-cost carrier (LCC) or low-cost airline, also called no-frills, budget or discount carrier or airline, is an airline that is operated with an emphasis on minimizing operating costs. It sacrifices certain traditional airline luxuries, for cheaper fares. To make up for revenue lost in decreased ticket prices, the airline may charge extra fees such as for carry-on baggage. As of April 2020, the world's largest low-cost carrier is Southwest Airlines, which operates primarily in the United States, as well as in some surrounding areas.