Few air carriers so aggressively match supply with demand like Allegiant Air.
In 2012, the Las Vegas-based carrier's capacity swung from a high of nearly 762,000 seats in March to a low of 431,000 seats in September, a 43% decrease, according to Capstats.
Though capacity fluctuations are not unique - all US airlines tinker with capacity to match seasonal demand - the degree of Allegiant's schedule flexibility sets it apart and helps produce strong financial results, say the airline and industry analysts.
"This is an airline that will run as hard as it possibly can in March. They will fly the airline to its capacity," says David Fintzen, an airline analyst in New York City with Barclays Capital.
Then, when demand slows in January and February, the airline waits out the slump by parking aircraft, he notes.
Allegiant reported operating profit of $52.4 million in the first quarter of 2013, up 44% from the same period last year. Its operating profit margin for the quarter was 19% and scheduled available seat miles climbed 17% year-over-year.
Allegiant, having reported profits in the last 41 quarters, attributes its financial success largely to flexibility.
"It's absolutely core to who we are and how we remain successful and profitable," the airline tells Flightglobal.
Flexibility is a strategy analysts say Allegiant perfects, but data from Capstats shows that US low-cost carriers tend to adjust their schedules to a greater degree than larger network carriers.
For instance, Miramar, Florida-based Spirit Airlines offered 26% fewer seats in February 2012 than in July of that year, while Dallas-based Southwest Airlines, including subsidiary AirTran Airways, flew 25% fewer flights in November 2012 than July.
JetBlue Airways, based in New York, had 19% fewer available seats in February 2012 than in July, according to Capstats.
JetBlue, Southwest and Spirit all reported profits for 2012 and for the first quarter of 2013.
By comparison, combined capacity at the four major network US carriers - United Airlines, Delta Air Lines, US Airways and American Airlines - was 15% lower in February 2012 than in July.
Fintzen notes that Allegiant's unique business model allows it to tinker with capacity more than competitors like Southwest.
"Southwest is there to provide frequency and schedule convenience. That's part of their model," he says. Allegiant, on the other hand, flies just a few times a week to many of its destinations.
"Allegiant is not there for mass transit," he says.
Allegiant says one of its most seasonal markets is Orlando, where it cuts capacity by 50% between July and September. Myrtle Beach in South Carolina is an entirely seasonal market, with no flights in winter, while Las Vegas and Phoenix are the least seasonal.
The airline is quick to make adjustments, announcing a few weeks ago it would convert most of its new Hawaii flights to seasonal service in August.
The announcement, made less than a year after most of the routes were launched, angered Allegiant's flight attendant union, whose leadership publicly accused the airline's management of making hasty route decisions.
Allegiant's capacity peaks in March, and is also high in summer and December. Capacity is lower in autumn and the first few months of the year, according to Capstats.
During periods of decreased demand Allegiant parks many of its aircraft at its Las Vegas base, using downtime to perform maintenance and operate charter flights, the airline says.
Allegiant keeps costs in check by flying older aircraft, and buying them with cash.
The bulk of Allegiant's fleet includes 56 Boeing MD-80-family aircraft, all manufactured in the 1980s, according to Ascend Online.
"This is an airline that buys old airplanes for a reason - so they don't' have to fly when there is no demand," says Fintzen.
Allegiant also flies six 1990s-era Boeing 757s, which it purchased to inaugurate flights to Hawaii. The airline says the aircraft will be redeployed on routes within the US mainland during the Hawaiian off-season.
Allegiant is slowly replacing its fleet with newer Airbus aircraft. It has acquired three Airbus A319s and plans to acquire seven A320s by the end of the year.
Allegiant has said it will eventually have nine A319s and nine A320s.
President Andrew Levy said in a media release in early May that the "market for used Airbus aircraft remains very attractive" and that an April A319 acquisition shows the airline's commitment to growing with "self-generated funds".