At 80 years old, the self-proclaimed father of the ultra-discount airline model is still swinging for the fences, stealing the spotlight at this year’s Dubai Air Show with the biggest order ever placed for Airbus SE commercial aircraft. William Augustus Franke, co-founder and managing partner of private equity firm Indigo Partners, joined Airbus on Wednesday in announcing the deal for 430 aircraft, which came with a price tag of nearly $50 billion. The transaction will fuel growth in Franke’s bare-bones airline empire, where he has spent the last part of his career avoiding what he calls “the path to hell” for an airline: creeping costs. “We’re firm believers in the ultra-low-cost model,” Franke told reporters in Dubai. “At the end of the day, in a competitive environment, the lower the cost, the lower the fares, is a winning strategy.” The Airbus planes Indigo ordered will be distributed among four carriers that sell customers deeply discounted tickets for an airline seat, and little else. Deliveries of the planes will start in 2021 to the carriers: Frontier Airlines in the U.S., Mexico’s Volaris, East European operator Wizz Air Holdings Plc and Chile’s JetSmart, which began operating this year. Unlike the volatile history of full-service carriers, Franke said he’s had a “remarkable run” with the airlines in Indigo’s investment portfolio. “Our airlines are all very profitable, they all produce cash.” Airline Career Franke co-founded airline investor Indigo Partners in Arizona in 2002 after leaving his job as chief executive officer of America West Holdings Corp. the year before. Indigo now has about $8 billion under management, according to Franke. He was chairman of convenience store chain Circle K in 1992 when he was tapped by Arizona Governor Fife Symington to take control of America West, despite Franke’s lack of experience in the industry. He raised $15 million in financing to help save the bankrupt carrier. Franke added chief executive to the chairman’s title in 1993 and led the airline out of Chapter 11 in 1994. Franke groomed Doug Parker, then 39, as his successor at America West after hiring Parker as chief financial officer. Together, the pair crafted a program to help improve the struggling airline’s on-time and financial performance. Parker currently is CEO of American Airlines Group Inc., the world’s largest carrier. Franke stepped firmly into the discount world in 2004 when he was named chairman of Tiger Airways in Singapore, a position he held five years. He also was an investor in Ireland’s Ryanair before it became publicly traded. Low-Cost Imperative The airline executive developed an iron discipline over the years in keeping costs from creeping upward. It’s just human nature when you’re enjoying success to let businesses and expenses expand, Franke observed at the press conference Wednesday. “Sometimes we see that happen with large airlines who have significant market positions as a low-cost carrier, and decide to do things like add clubs or add frequent-flier programs, or improve the service and offerings on board,” he said. “All of that creates a path to hell.” He helped push the transformation of Spirit Airlines Inc. into an ultra-discounter before stepping down as non-executive chairman there in 2013, when Indigo sold off its 17 percent stake in the Miramar, Florida-based carrier. The move allowed Franke’s firm to purchase Frontier out of bankruptcy and convert it to an ultra-discounter. He’s now chairman of Frontier, which earlier this year delayed an initial public sale of shares. It took months to finalize the latest purchase agreement with Airbus, Franke said. The deal also helps seal the legacy of Airbus sales chief John Leahy, 67, who will retire in coming months. The order is valued based on the list prices for the planes, although airlines typically receive discounts for large orders. “Their objective is to sell aircraft at the best possible price,” Franke told reporters in Dubai. “Our objective is to buy aircraft at the best possible price. I’ve known Mr. Leahy for 25 years. Sometimes he wins, sometimes I win.” Who won this time? “That’s a good question,” he said with a smile.