Greg Herrick is trying to save the world, one vintage airplane at a time.

Herrick made his fortune pioneering direct-mail computer sales with his company Zeos International Ltd. during the 1990s. In 1993, he bought his first collectible plane, a Fairchild PT-26, a twin-seat military trainer. Ever since, he has been collecting what he calls the golden age of civilian aircraft, the period between World War I and World War II.

Herrick got his first pilot's license while still a teenager growing up in Ottumwa, Iowa, where he watched planes flying to the nearby Antique Airplane Association. "Vintage aircraft was sort of imprinted in my brain," he says.

His passion led to such a collection that he has turned it into the Golden Wings Museum in Blaine, Minn. With an investment of more than $10 million, he has about 40 craft on display; it is one of the nation's largest collections of vintage airplanes. Most are in flying condition, and several more are ready for restoration, or "resurrection," as he refers to it.

With exotic names evoking a bygone era, these planes maintain a tangible link to America's flight heritage. There's the 1928 Stearman CB3, a biplane mail carrier with an open cockpit that was the first plane built at the Stearman Aircraft Corp. plant in Wichita, Kan. And the 1927 Ford Trimotor flown by both Charles Lindbergh and Amelia Earhart. It's the oldest airliner still flying.

For Herrick, sometimes the rescue mission is more interesting than the ownership. "It's the thrill of the chase for some of this stuff," he says. For example, he has been trying to pull a Sikorsky S-39 seaplane off the bottom of an Alaskan lake. The plane, stuck in 213 feet of glacial silt at the lake's bottom, has already resisted two expensive recovery attempts. Herrick has not given up and plans to try again.

"My interest is in preserving aircraft from the golden age that otherwise might not be preserved and to share them with people," he says. "Not necessarily one-of-a-kind aircraft, but unusual or rare aircraft in danger of disappearing, or that have almost disappeared and all that's left is a bunch of tubing and pieces of wings. It's critical, when you have something like that, not to keep it locked up in a hangar. I view my role as not ownership, but stewardship."

While Herrick does virtually all his restoration in-house, many collectors of military aircraft, such as Microsoft Corp.'s Paul Allen, owner of the Flying Heritage Collection in Everett, Wash., seek out restoration specialists such as Carl Scholl of S&R Aviation Services Inc., known as Aero Trader, in Chino, Calif. For Scholl, a sense of military history and honor mixes with the fascinations of a mechanic.

Discovering a derelict WWII B-25 bomber at an out-of-the-way airport in California 32 years ago, he followed his whim, plunked down $1,000 and bought it. Now he and his partner have, by Scholl's estimate, the largest warbird restoration facility west of the Mississippi River.

Scholl's company has a full complement of fabrication equipment for P-51 Mustangs, one of the most sought-after fighters of WWII. In fact, Aero Trader can build one virtually from scratch. But its primary specialty is restorations of B-25 bombers, famed for their use in the Doolittle raids on Tokyo in 1942. There are only about 40 B-25s still flying, and Aero Trader claims the largest inventory of B-25 parts in the world. "We have the corner on a very small market," he says.

The company operates out of 35,000 square feet of hangars, workshops and storage areas next to the Chino airport. In a dust-filled hangar with the ear-splitting din of hammers and high-speed drills, he shows a visitor a rare sight: A B-25 Mitchell WWII bomber being restored in the most immaculate and authentic way possible. Every part of this massive war machine has been removed, restored or refabricated, right down to the machine guns.

"We've been working on this for Paul Allen for almost seven years and have quite a bit more to do before it's done," he says. Total investment in this sort of project will run into several million dollars and will take close to 10 years.

But you don't have to spend millions to have a collection you can be proud of. Bill Allen, president of San Diego's Crystal Pier Hotel & Cottages, who also sits on the board of the San Diego Air & Space Museum, got started in a partnership. He traded up until he now owns six fully restored vintage planes and has chartered his own museum at Gillespie Field in El Cajon, Calif., where he and his wife Claudia developed 21 huge units of combination hangars and living facilities. Resembling a suburban housing development with hangars instead of garages, they line the
airport's tarmac.

Inside the hangar where his collection is housed, he climbs onto an airplane's wing and pulls the cockpit cover back, showing the interior of an carefully restored midnight blue Stearman PT-17 biplane -- the iconic PT-17 was used for decades as a crop-duster. Built by Boeing Co. in the mid-1940s, it is a beautiful example of aeronautical engineering, and this one's allure and value are enhanced by its provenance -- until the Allens acquired it, it was the last plane owned by Steve McQueen. No matter what he might eventually do with his collection, Allen says, "I'm keeping the McQueen."

Claudia Allen became so involved with her husband's pastime she became a member of the National Board of the Smithsonian Institution.

"There's just so much provenance with airplanes like that," she says. "They become like this living, breathing, soulful, inanimate object. Having the Steve McQueen Stearman is kind of like icing on the cake in that you don't have just the standard airplane. I think it's exciting. It excites other people."

The Allens' collection goes beyond airplanes. They also have rooms filled with artifacts of flight -- uniforms, medals, pieces of the Hindenburg, photos, documents, books and the nearly 500 posters celebrating early air shows and airplane-themed movies. Although he has other planes, Allen, like many others involved in collecting, seems to have a soft spot for one type -- in this case, the Stearman biplanes -- and he suggests them as a good starting point for involvement.

"You can pick up an airworthy Stearman for $80,000 to $120,000, and this is a great time to get in. Some people start out putting a lot of money into a plane or two, then decide for one reason or another to sell them. That's what you want to find."

Larry Tobin, a retired Trans World Airlines pilot from Spokane, Wash., who began collecting 10 years ago with a 1942 Stearman, has slightly different advice. "Buy a flying airplane that's getting tired, then turn it over to a restoration facility and get a first-class airplane." Tobin had enough expertise to restore his own plane, and helps restore others at Spokane's Felts Field.

But if you do want to start at the top, there are brokers such as Simon Brown who will be glad to help. In 2005, he and his partner opened Provenance Fighter Sales Inc. in Murrieta, Calif., and it's now the largest dollar-volume broker of vintage planes in the country. In 2007 Brown sold his own P-38 Lightning for $7 million, the most expensive warbird sale to date. P-38 Lightings, P-51 Mustangs and other glamorous fighters are worthwhile investments, Brown says. "Almost every classic World War II fighter airframe has been located and restored, so over the last five years they've increased anywhere between 10% and 20% annually."

The P-51 Mustang seems to be the standard for restored WWII fighters. "The nice ones," Brown says, "are going in the $1,700,000 to $2,000,000 range and, for a dual-control version, about $2,500,000 to $2,800,000." The market for fighters remains very strong, Brown says. "In 2004, 2005 and 2006, there were more sold than in the last 10 to 15 years combined."

You may have missed the run-up to the high-flying fighter market, but there are plenty of other options where a budding collector can get in early. In 1987, retired Delta Air Lines Inc. pilot Ross Diehl bought a 1949 T-28A military trainer. It's possible to pick up a similar plane for around $100,000.

Diehl is a member of EAA Warbird Squadron 16 in Chino, part of EAA Warbirds of America, a national association of warplane owners. Before becoming a commercial pilot, he had been one of Lockheed Corp.'s lead test pilots, flying at speeds up to 1,400 miles per hour in a Lockheed F-104 Starfighter.

His affection for vintage planes is long-standing and strong. "These old warplanes were used by some pretty magnificent people that did an absolutely magnificent job back in World War II of returning the world to a degree of civility," Diehl says. "Today we try to use these planes to revive the feeling that existed back in those days -- 'All for one, and one for all.' "