For anyone who travels frequently, it might seem that owning your own private jet would be the ultimate way to go. But often, owning just a piece of a jet can be even better. "Fractional programs offer a substantial convenience factor," says aviation consultant Brian Foley. "What if you have three people in three different places who all need to get to the same meeting? With a fractional program, you can schedule that."

Technically, as a fractional owner, you buy a share of one specific airplane, but in practice, you gain access to any airplane in a given fleet. So if you need three airplanes all at once, that isn’t a problem. If "your" airplane is down for maintenance, you can just take another. And if for certain missions you need a larger airplane, or a smaller, more efficient one, you can trade your hours for the most practical choice. Plus, with a fractional program, you don’t have to worry about hiring and training a crew, renting hangar space, or scheduling maintenance. The provider will take care of all of that, and often include catering and ground transport as well.

NetJets pioneered the concept of fractional ownership for jets back in the 1980s, and today it is still the market leader, with a stable of over 800 aircraft. Customers can choose from a fleet of light, midsize, and large jets, from the seven-seat Cessna Citation Bravo to the Boeing Business Jet, which can carry 18 passengers in comfort and fly nonstop for over 6,000 miles. Like most providers, NetJets typically offers five-year contracts, starting at a one-sixteenth share, or about 50 hours of flying time per year.

Despite their conveniences, fractional contracts can be quite complex and lengthy, Foley says. Buyers will do best if they have a clear idea of how they will use the airplane—how many hours per year, for short or long or globe-circling trips, and what standard of service and luxury they expect. Ask about rules for travel on peak dates, guaranteed response times, and fees for empty legs.

Flexjet exclusively flies Learjet and Challenger aircraft, which are built by its parent company, Bombardier. Since launching in 1995, the fleet has grown to over 100 airplanes, with an average age of less than four years. Last year, the newest Bombardier jet, the Challenger 605, was added to the line. It offers a larger cabin and bigger windows than earlier models. The company commits to providing aircraft with as little as six hours’ notice and guarantees that clients will fly on Flexjet-managed aircraft at least 95 percent of the time.

CitationShares, a division of the Cessna Aircraft Co., includes a selection of the popular Cessna Citation jets—Bravo, CJ3, XLS+, and Sovereign. All of the aircraft are factory-maintained. The company offers a variety of options to help keep the program simple and economical. Customers who don’t need the airplane during peak times, for example, can realize substantial discounts. Seats on empty legs are sold on short notice at low fares and don’t count against your contract hours.

Avantair flies only the Piaggio Avanti P.180, a versatile, fuel-efficient twin turboprop aircraft that can operate from short runways. The roomy cabin provides seating for seven in its standard configuration, and the airplane can climb quickly to high altitudes for a smooth nonstop 460-mph flight from New York to Miami, Dallas, or Chicago. For owners who operate mainly in the United States, the Avanti can be an economical choice.

Other options for travelers include simply chartering an airplane by the hour on an as-needed basis, which can be a practical route for the occasional flyer. Jet cards work like gift cards, bought in advance for a set number of hours. Jet-card users avoid the up-front capital cost of buying a share in an airplane, and the arrangement is less complicated. But for frequent fliers, says Foley, the per-hour cost will probably work out to be higher than in a fractional program.