EVERETT — If only all Paine Field hangars were as tidy as the one where Les Smith and Frank Hummel keep their Cessna Cardinal.

Spotless, with almost no clutter, the T-shaped garage they lease from the Snohomish County Airport shines showroom clean. Aside from a few necessities on shelves or benches, their lightweight private aircraft is about the only thing inside.

That’s not the case in some of the airport’s other hangars.

“There is no doubt that there are some who consider this their man cave,” said Smith, 63, of Mukilteo, who owns the Cessna jointly with Hummel, 55, of Woodinville.

“Or their junk yard,” airport director Dave Waggoner said.

With just about everything aviation-related commanding a premium price, it may come as a surprise that renting Paine Field hangar space is cheaper, by the square foot, than many local storage facilities. It often costs half or less.

That creates temptation.

The airport has warned tenants about a growing problem of people using hangars to store household junk, spare parts, cars and all sorts of other stuff that has nothing to do with piloting airplanes.

For a number of reasons, that doesn’t fly.

To start with, there are airport and Federal Aviation Administration rules meant to ensure that Paine Field focuses on its core mission of supporting general aviation.

Fire and building code problems also can crop up when hangar space becomes cluttered or gets modified.

It’s an issue of fairness as well, since hangar space at Paine Field is relatively scarce. Waiting lists can last from a year, on the short end, to several years, depending on the type of hangar, Waggoner said.

“We would be subsidizing the storage of personal gear at the expense of supporting general aviation,” he said. “We’re a customer-service organization, but at the same time you can’t let people abuse the public resource in the airport.”

The problem isn’t unique to this area.

“The issue of storage of non-aeronautical items in hangars is a common issue that many airports face,” said Allen Kenitzer, a Renton-based FAA spokesman.

Airports that don’t comply with federal regulations risk losing out on grants.

“In the past, the FAA has found some airports in violation of their grant obligations where non-aeronautical use of hangars has been excessive,” Kenitzer said.

The county owns 297 hangars at Paine Field. That’s on top of privately owned hangar space.

All told, about 650 aircraft are based at the Snohomish County Airport, including those that are tied down and not stored in hangars.

Typical hangar sizes at Paine Field include L-shaped enclosures of 510 square feet and above, T-shaped hangars of 1,040 square feet and above, and rectangular hangars of up to 3,600 square feet.

The smaller hangars cost between $150 and $230 per month. The monthly tab for the largest public hangars runs $1,730.

The main article in the airport’s March newsletter warned people against using those spaces inappropriately.

“One tenant justified having heaters and large propane tanks in his hangar because he was in the construction business and needed the heaters for his work,” Waggoner wrote. “There was an aircraft in the hangar, but it would have taken several hours to get it out because of the stored items in front.”

Airport staff plan to inspect all hangars and work with tenants on compliance.

Noah Haglund: 425-339-3465; nhaglund@heraldnet.com.