On October 25, 2016 JetSuiteX announced that JetBlue had made a minority equity investment in JetSuiteX. Part of the agreement also gave JetBlue a seat on JetSuite's board of directors. Reasons for the investment was outlined by CEO Robin Hayes "Our investment in JetSuite makes sense as we continue to execute on our west coast plan and invest in innovative ideas that reflect the disruptive spirit of JetBlue." In JetBlue's 1st quarter 2018 investor call JetBlue's CFO Steven Priest Confirmed they currently hold about 10%  of JetSuiteX.
In 2014, Frontier announced it would be transitioning into an ultra-low cost carrier. Frontier will also cut several flights and jobs at their Denver hub and transition them to different markets. On January 16, 2015 Frontier announced that it will close both its Denver and Milwaukee call centers, laying off 1,300 employees and outsourcing the jobs to call center company, Sitel, which operates a large call center for Frontier in Las Cruces, New Mexico. As part of its transition to an ultra-low-cost airline, Frontier Airlines joined Spirit and Allegiant in June 2015 in removing its toll-free telephone number for customer service.
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 Many of these incidents had involved Allegiant's aging MD-80 aircraft, which as of November 2018 have been replaced by newer Airbus A320 family aircraft. 46 of the 86 aircraft have made emergency landings, all of which were on MD-80s.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 March 2010, Allegiant purchased six used Boeing 757-200 jetliners as part of plans to begin flights to Hawaii, with deliveries from early 2010 to the fourth quarter of 2011. It gained the approval for type with the FAA in July 2011, and then worked with the FAA to obtain the appropriate ETOPS rating in order to be able to serve Hawaii. Allegiant no longer operates nonstop service to Honolulu from Las Vegas.