The airline tends to offer lower fares, which requires strict cost control.[33] Part of the airline's lower cost structure included operation of McDonnell Douglas MD-80 jets, which the airline can purchase and refurbish for as little as $4 million.[40] While the aircraft are less fuel-efficient than newer planes, Allegiant was able to purchase used MD-80s outright for one-tenth the cost of a new Boeing 737 although Allegiant has subsequently purchased used Boeing 757-200s, Airbus A319s and Airbus A320s.[13] (The 757s were acquired for its Hawaii service while the Airbus jets were beginning to replace MD-80 aircraft). As of November 2018, however, Allegiant no longer operates any MD-80 aircraft, relying instead on an all-Airbus fleet.[50] Given the low cost of ownership, Allegiant is able to operate its aircraft less (seven flight hours per day on average versus 13 hours per day at JetBlue Airways), which helps keep labor costs lower.[13] Overall, Allegiant operates with 35 full-time workers per plane compared to more than 50 at other carriers. Allegiant schedules their crew members so that they always return to their domicile at the end of the day, thus avoiding the need for hotel rooms which can be a costly expense for airlines.[40]

In January 2010, the airline celebrated its one-millionth passenger to fly out of Phoenix-Mesa Gateway Airport. Allegiant's parent company also announced that it had purchased 18 new MD-80 aircraft from Scandinavian Airlines.[20] In February 2010, Allegiant opened its ninth base at Grand Rapids' Gerald R. Ford International Airport in Michigan. The airline based two McDonnell Douglas MD-80 aircraft in Grand Rapids, but ended their airport's status in 2011. The airline continues to fly out of Grand Rapids in a reduced capacity.[21]

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.[32] 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.[33] In October 2009, Allegiant had competition on just five of its 136 routes.[34] 

In September 2009, JetBlue made changes to its TrueBlue program.[132] In the new program, members receive three points for every dollar spent toward a flight, excluding taxes and fees, plus an additional three points for every dollar spent on a flight if booked online directly on the JetBlue.com website. Additional points are awarded if the member uses the Barclay's issued JetBlue Mastercard credit card to purchase the flight. The price of flights in points depend on the fare of the flight in U.S. dollars. The new program launched on November 9, 2009.[133][134]
In 2011, JetBlue made interline agreements with Virgin Atlantic and Jet Airways, both of which have since been terminated.[112][113] Since 2012, JetBlue has had an interlining agreement with Air China. It also established an interline agreement with Porter Airlines connecting from Billy Bishop Toronto City Airport to US destinations through Boston and Newark.[114]
In the fall of 2001, Allegiant exited bankruptcy and the case was officially closed in early 2002.[14] 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.[15] 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.
In July 2017, Frontier announced 21 new cities and 84 new routes. These cities include Buffalo, Charleston, S.C., Pensacola, Jackson Hole, Palm Springs, San Jose, Reno, Little Rock, and Tulsa. Destinations that saw a significant bump-up in new service include Austin, Cincinnati, Long Island/Islip, N.Y., Miami, Orlando, Providence, San Antonio, and Tampa.[68]
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.[32] 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.[33] In October 2009, Allegiant had competition on just five of its 136 routes.[34]
A November 2016 analysis by the Tampa Bay Times noted that Allegiant's planes were four times more likely to have in-flight failures than other major US airlines.[64] A 60 Minutes report by CBS News in 2018 continued to investigate the issues first raised by the Tampa Bay Times.[65] Public records cited in the investigation found that the airline had more than 100 serious mechanical incidents between January 1, 2016 and October 31, 2017, including "mid-air engine failures, smoke and fumes in the cabin, rapid descents, flight control malfunctions, hydraulic leaks and aborted takeoffs."[65] Other public records further revealed that Allegiant aircraft, on average, were nearly three and a half times more likely to have mid-air breakdowns than American, United, Delta, JetBlue and Spirit.[65]

We arrived at the airport at 5:15 for our 7:15 flight. After two delays we received a text message from the company that the flight had been canceled. 35 minutes later an employee finally came out to announce the cancellation. As we started asking questions like “will we get our money back” or “do you have any more flights going out we can get on” each time a piece of paper was picked up and shaken in our faces and were told to read the paper just like everyone else. Worst service ever!!!!!! We were all states away from home with no where to go and no help from frontier. And our refund could be expected within two weeks. All I could think of is how I hoped everyone there could find funds to purchase another ticket to where they were going. Because last minute tickets are crazy expensive. I will never fly frontier again!!!! They gave me a $100 voucher off my next flight with them but I’ll never use it!!!
JetBlue's in-flight options consist of gate-to-gate Fly-Fi service, offering over one hundred channels of DIRECTV, Sirius XM Radio, and movies, and on the Airbus A321, a 15″ interactive video screen which is not available on the rest of the fleet. JetBlue's partnership with Amazon lets customers watch Amazon Prime videos by connecting to Wi-Fi and downloading the Amazon Video app on their mobile phone or tablet. The in-flight WiFi under the "Fly-Fi" network is complimentary on all flights, at speeds of 12–15 megabits per second.
On July 1, 2010 Allegiant returned to Long Beach Airport (LGB) in Long Beach, California having previously served LGB with DC-9 jets with nonstop flights to Las Vegas (LAS) and Lake Tahoe (TVL) in 2000.[22][23] The airline also intended to fly from Bellingham International Airport and Stockton several times a week; however, there is no service at present flown between these two cities although Allegiant continues to serve Stockton with flights to Las Vegas, Phoenix/Mesa and San Diego.[24] In November 2011, Allegiant closed its Long Beach facility and consolidated all Los Angeles area flights at Los Angeles International (LAX).
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