Air travel is undoubtedly the fastest and the safest way to travel which opens up a market for several companies to become your preferred airlines. In such a scenario, when the passenger is literally spoilt for choice and can easily acquire the best deals easily, it sometimes ironically becomes difficult for one to choose any one airline amongst so many. This is why an airline which can make permanent customers out of first time fliers is the one that can actually survive. One such airline is the Allegiant Air.
In 2007, jetBlue was also facing reliability problems with its Embraer 190 fleet. For a couple of months, jetBlue contracted ExpressJet to operate four Embraer 145 regional jets on behalf of jetBlue. While this was going on two E-190 aircraft at a time were sent to an Embraer maintenance facility in Nashville, Tennessee. ExpressJet operated routes between Boston Logan and Buffalo, New York and Washington Dulles, and between New York–JFK and Columbus, Ohio (has terminated) and Richmond, Virginia.
Allegiant Air has been closely monitored by the FAA due to many emergency landings and aborted takeoffs. ABC interviewed a former Allegiant mechanic, who said "Dedicated steps were not being performed with maintenance manuals or even with general practices, before an aircraft is released." Many of these incidents had involved Allegiant's aging MD-80 aircraft, which as of November 2018 have been replaced by newer Airbus A320 family aircraft. 46 of the 86 aircraft have made emergency landings, all of which were on MD-80s. The average age of Allegiant's MD-80 fleet was 29 years compared to less than 13 years for its Airbus fleet.
In May 2017, Allegiant Air took delivery of its first brand-new A320. Allegiant took delivery of ten new A320s in 2017 and is scheduled to accept two in 2018. All new aircraft will be painted in Allegiant's new livery at the time it is delivered. Older Airbus aircraft will be repainted during their C-checks. The new Airbus aircraft will have fuel-efficient sharklets. The new A320s seat 186 passengers, an increase of the 177 seats that are found in the rest of the Allegiant A320 fleet. To fit the additional nine seats, Allegiant opted for the Airbus Space-Flex V2 Lavatory. 
Animal concepts used in the livery extend into Frontier's marketing as well. Each animal has a specific name. 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.
Allegiant aims primarily to serve leisure travelers, particularly those in colder northern climates, going to warm-weather tourist destinations such as Punta Gorda, Tampa Bay, Las Vegas, Orlando, Los Angeles and Phoenix. It also serves smaller destinations that see few direct flights by major carriers. Many of the airline's markets, such as Peoria, Illinois, are served only by commuter service requiring a connection at an airline hub. In October 2009, Allegiant had competition on just five of its 136 routes.
In an effort to focus on regional contract flights for major carriers, Republic Airways Holdings announced in January 2012 its intention to sell or spin off Frontier. On January 26, 2012, Republic Airways Holdings appointed former US Airways and Gate Gourmet CEO David Siegel as President and CEO of Frontier Airlines. Republic also added new senior officers for Frontier's finance and commercial team, among other changes in the executive leadership team. Siegel and other Frontier executives moved to Denver where Frontier is headquartered in order to facilitate management of all aspects of Frontier during its separation process from Republic and continue its transformation into an ultra-low-cost carrier.
In the fall of 2001, Allegiant exited bankruptcy and the case was officially closed in early 2002. In March 2002, Allegiant entered into a long-term contract with Harrah's to provide charter services to its casinos in Laughlin and Reno, Nevada. At the same time, the airline acquired its first McDonnell Douglas MD-80 jetliner. From 2002 through 2004, the airline developed its scheduled-service business model. By 2004, Allegiant was flying from 13 small cities to Las Vegas offering bundled air and hotel packages.