Frontier Airlines is an American ultra low-cost carrier headquartered in Denver, Colorado. The eighth-largest commercial airline in the US, Frontier Airlines operates flights to over 100 destinations throughout the United States and six international destinations, and employs more than 3,000 air-travel professionals.[15] The carrier is a subsidiary and operating brand of Indigo Partners, LLC, and maintains a hub at Denver International Airport with numerous focus cities across the US. In August 2018, Frontier began connecting passengers with Mexican low-cost carrier Volaris under a codeshare agreement.[16]
Animal concepts used in the livery extend into Frontier's marketing as well. Each animal has a specific name.[87] Animal aircraft used in their radio and television commercials include Jack the rabbit, Grizwald the bear, Foxy the fox (for whom Jack has a crush), Flip the dolphin (who always gets stuck going to Chicago rather than the warmer climates the others are going to), Larry the lynx, Hector the sea otter, and Sal the cougar. New additions are Penguins Jim, Joe, Jay, and Gary, a barbershop-style quartet, singing the praises of EarlyReturns to an audience of Frontier's well-known characters from the "a whole different animal" campaign, Hector the otter, advertising Frontier's expanding service to Mexico, and Polly the Parrot, who won the new animal audition in 2012.
Frontier has a three-tier frequent flyer status program. The tiers are Elite 20K (earned by flying 20,000 Status Qualifying Miles [SQM] or 25 segments in a calendar year), Elite 50K (50,000 SQM or 50 segments), and Elite 100K (100,000 SQM or 100 segments). Elite benefits include free carry-on and checked bags, advance seat assignment and family seating, priority boarding, redemption fee waiver, stretch seating, Discount Den membership, and mileage multipliers.[74]

In October 2013, jetBlue introduced Mint, a premium cabin service on transcontinental and select Caribbean flights. The service began in 2014, using the Airbus A321-231 aircraft ordered by jetBlue. These planes are outfitted with winglets, as well as with "lie flat" seats, and moveable partitions that can create small suites on the airplane.[56] Called "Mint" by jetBlue, these planes are configured with 16 business-class seats and 143 economy seats, instead of an all-economy configuration of 190 seats.[57]
Nevada-based Allegiant (G4) is a low-cost carrier that flies all Economy Class aircraft to about 100 destinations in 40 US states. On many routes, it only operates a couple times a week, and it typically flies to smaller, regional airports. However, Allegiant's focus cities include a mix of smaller and larger airports, including Bellingham International Airport (BLI), Fort Lauderdale–Hollywood International Airport (FLL), Los Angeles International Airport (LAX), Las Vegas's McCarran International Airport (LAS) and Phoenix–Mesa Gateway Airport (AZA).
On November 15, 2017 Frontier Airlines announced a $15 billion order for 134 additional A320neo family aircraft. The order, slightly revised under new owner Indigo, consists of 100 A320neo and 34 A321neo. The order also includes the conversion of the remaining A319neo to A320neo.[80] With this order, Frontier Airlines fleet has industry-leading fuel efficiency. The fleet is also one of the most modern and young, particularly in comparison to other low-cost carriers,[nt 1] at an average age of 5 years as of 2018.[81]
Dave Siegel took the chief executive officer role in January 2012.[62] Siegel's tenure ran through May 2015, when he left for personal reasons and was succeeded by the company's chairman, Bill Franke, who would manage strategy and finances.[62] In April 2014, Barry L. Biffle was appointed as the company's president, reporting to Siegel;[63] after Siegel's departure, Biffle was charged with managing the company's day-to-day operations.[62]