Kelleher is the founder of a low cost and highly profitable airline. Southwest has refined the low-cost, no-frills, no-reserved seats approach to air travel, providing over 2,300 flights daily to about 52 cities in 26 states, with a fleet of 280 aircraft. The company uses only fuel-efficient Boeing 737s in order to reduce pilot training and maintenance cost. The airline is known for its participative corporate culture and a strike-free, unbroken record of consistent profit.