US ultra-low-cost carrier Frontier Airlines is reviewing its full-year guidance amid a spike in fuel prices linked to the war in Iran. "An update will be provided in conjunction with the release of first quarter 2026 results," Frontier says in a 17 March filing to the US Securities and Exchange Commission. The Denver-based carrier notes jet fuel prices have "increased significantly" since it last issued guidance. Prices are now expected to average approximately $3 per gallon for the first quarter of 2026 based on the jet fuel curve as of 13 March, compared to the $2.50 per gallon price that underpinned its prior guidance, noting that that will drive approximately $45 to $50 million incremental fuel expense in the first quarter of 2026. "Frontier's fuel efficiency advantage of over 40% compared to the major US carriers is expected to better position the company to mitigate the impact of elevated fuel prices, should the higher fuel prices persist," it says. At the ISTAT Americas conference in San Diego on 9 March, Frontier's president and chief executive James Dempsey said its A321neo fleet "will be very helpful in today's environment" given that oil prices had been "spiking over the last four or five days, quite considerably". Frontier says in the 17 March filing that it now expects first quarter 2026 adjusted (non-GAAP) diluted loss per share of between $0.32 and $0.44, which is within its prior guidance range. This, it adds, is driven by significantly higher revenue performance during the quarter, albeit offset by the recent spike in jet fuel prices and operational disruptions arising from storms on 15 and 16 March, "with lingering impacts expected in order to restore normal operations". Its underlying expectations regarding first quarter 2026 expected tax expense of $3 million to $5 million and approximately 229 million of weighted average shares outstanding on a diluted basis remain unchanged from its prior guidance. It says "strong travel demand, moderating competitive capacity, and continued progression" of its revenue management initiatives are "driving meaningfully higher unit revenues". It now expects adjusted RASM to increase by mid-teens on a percentage basis over the corresponding prior year quarter, higher than prior guidance, and adds that strong demand and fare trends are extending into the spring booking season, "supporting meaningful expected revenue growth relative to the corresponding prior year period." Frontier expects total liquidity at the end of March 2026 to be over $900 million, an increase from $874 million reported at the end of December 2025.

Allegiant Travel Company's waiting period to receive US antitrust clearance for its proposed acquisition of Sun Country Airlines has been terminated early. The parent of Allegiant Air says the early termination of the waiting period under the US Hart-Scott-Rodino Antitrust Improvements Act of 1976 is "an important step toward completing the combination of the two airlines". The Hart-Scott-Rodino act establishes waiting periods that must elapse before the consummation of company acquisitions, says the US Federal Trade Commission. It requires companies to file pre-merger notifications with the FTC and the Antitrust Division of the Justice Department for certain acquisitions. "We are pleased to receive US antitrust clearance from the Department of Justice," Allegiant chief executive Greg Anderson states. "Together, Allegiant and Sun Country will create a stronger leisure-focused airline, offering a broader network, more travel options and increased long-term value creation for our shareholders." Allegiant notes that the acquisition of Sun Country remains subject to other customary closing conditions, including approval from the Department of Transportation and from Allegiant and Sun Country shareholders. The US carriers now expect the transaction to close in the second or third quarter of 2026, a revision of their previous expectation of closing it during the second half of 2026. Allegiant and Sun Country in January agreed to combine in a cash and stock deal valued at $1.5 billion. Each will operate separately until they obtain a single operating certificate. The combined company will be headquartered in Las Vegas, where Allegiant is based, and maintain a presence in Minneapolis-St Paul, home to Sun Country.

Spirit Airlines intends to reduce the size of its fleet to between 76 and 80 aircraft by the third quarter of 2026. At 16 March, the Florida-based carrier operates a fleet of 175 Airbus jets comprising 62 A320ceos, 63 A320neos, 29 A321ceos and 21 A321neos, Fleets data shows. Seven months ago, on 13 August, Spirit operated a fleet of 214 Airbus aircraft. In late August 2025, Spirit filed for Chapter 11 bankruptcy protection for the second time in 10 months Spirit's reduced fleet will "primarily" consist of A320ceos and A321ceos, it says, adding: "In addition to previously announced fleet adjustments, the planned adjustment will further reduce Spirit's debt, lease obligations and aircraft costs." Sean Lane, a judge at the US Bankruptcy Court for the Southern District of New York, on 12 March approved Spirit's proposed bidding procedures to govern the sale of 20 used A320s and A321s. The carrier – which on 13 March filed with the US Bankruptcy Court for the Southern District of New York a restructuring support agreement and reorganisation plan – intends to emerge from Chapter 11 in the late spring or early summer.