American Airlines, Delta Air Lines, and United Airlines are the three largest airlines in the United States by fleet size. Each has a mainline fleet of around 1,000 aircraft. While all three operate large widebody fleets and fly to international destinations worldwide, most of their aircraft are narrowbody, with domestic routes being predominant.
As full-service legacy carriers, these airlines maintain a higher level of service compared to low-cost carriers like Allegiant and Frontier. These low-cost carriers focus on minimizing services, offering only economy seats without in-flight Wi-Fi. In contrast, American Airlines, Delta Air Lines, and United Airlines provide more amenities even in economy class.
The Boeing 737-800 is a common aircraft among these airlines. Delta operates 77 of them with 160 seats each; United has 141 with 165 seats; and American operates 303 with 172 seats. The seat configurations vary slightly between airlines. For instance, Delta's economy class seats have a width of 17.3 inches and a pitch of 31-32 inches. United's regular economy class seats range from 16.3 to 17.3 inches in width with a pitch of 30 inches. American's seats are between 16.6 to 17.8 inches wide with a pitch of 30 inches.