Most of Spirit Airlines' fleet is grounded. But a few of its bright yellow planes were in the air this week — including Nomadic Flight 189 from Spirit's former hub in Fort Lauderdale, Fla. to Phoenix Goodyear Airport.

It wasn't carrying any passengers, just a skeleton crew ferrying the plane to Arizona for storage.

When Spirit Airlines stopped flying last weekend, it left more than 90 planes at dozens of airports around the country. Spirit also has engines, spare parts, real estate, and other valuable assets that it's hoping to liquidate. Within days, Spirit's lawyers were in court asking for permission to start an "orderly wind-down of operations."

This is complicated because Spirit doesn't actually own most of its planes. The majority — more than 60 planes, nearly two-thirds of its active fleet — were leased, according to court filings. And the owners want those planes back.

"Everybody tries to move them as quickly as possible," said Steve Giordano, the managing partner of the Nomadic Aviation Group, which is in the business of ferrying planes across the country. He works with six of the companies that own Spirit's jets.

"Some are already probably in the pipeline to be leased again. Some are going to have the engines removed, moved on to different airframes and those aircraft are going to get leased. Some are going to get parted out. Some, nobody knows," Giordano said in an interview.

Spirit, too, is looking to monetize anything it can: planes, engines, gates, even landing slots at congested airports. According to court filings, Spirit has 28 planes it could sell, all of them in the Airbus A320 family. It also owns an office building in South Florida, maintenance facilities, and other assets that another airline might want to buy.

"Spirit has gates at some very important, very popular airports," said Henry Harteveldt, an airline analyst at the Atmosphere Research Group, including international airports in Houston, Dallas, Las Vegas and Los Angeles.

"I wouldn't be surprised if we saw some other airlines try to get at least some of Spirit's gates at some of these other airports," he said.

Spirit also holds some coveted takeoff and landing slots at LaGuardia Airport in New York and Newark Liberty International Airport in New Jersey.

"You can easily sell slots at those constrained airports, and many airlines will be in line to buy them," said Ahmed Abdelghany, a professor of operations management at Embry-Riddle Aeronautical University in Florida.

The first challenge for the companies trying to repossess Spirit's planes is just getting to them. Right now, they're parked at airport gates, or wherever they happened to be when Spirit ceased operations. "It's an environment of mass confusion," Giordano said. "No one wants to touch them. There's no real method for getting them."

Nomadic is sending qualified pilots to fly these planes — in some cases, pilots who worked for Spirit until very recently, Giordano said. But they're often wearing jeans and t-shirts, not airline uniforms, and sometimes encounter considerable resistance.

"You go up to a person of authority and say, 'I need to get on that airplane, I'm repossessing it.' And the first thing they're going to say is, 'no, no, no, no, no,'" Giordano said. "They're going to call out the sheriffs, the airport police, the airport managers. And everybody's instinct is always no."

The biggest problem facing Spirit and the many companies that own its jets may be timing.

"One of the challenges for Spirit and its creditors is that the high cost of jet fuel makes many of Spirit's planes less appealing to acquire," Harteveldt said.

The price of jet fuel is up about 70% since the war in Iran began in February. That's part of the reason Spirit went under, and other airlines are burning through cash too. Harteveldt says that's creating uncertainty in the industry, just as Spirit is trying to sell its assets.

"I think the airline will find buyers. It just may be a slower selling cycle than had this happened a few years ago or even just like, say, three months ago," Harteveldt said.

That means many of those bright yellow planes may be sitting in the desert in Arizona for a while.