Adjust font size: (Budget Travel Online) -- Planning a trip with multiple flights can eat up your time, money and patience. That's why flight passes seem so attractive: You buy several flights at the same time for a set price that's often cheaper than booking piecemeal.
Cathay Pacific's All Asia Pass, for instance, includes airfare to Hong Kong from New York, Los Angeles, San Francisco, Toronto or Vancouver, as well as connecting flights to 18 Asian cities over the course of 21 days -- all for $1,499.
But air passes aren't as simple as they sound. Taxes might add hundreds to the advertised fare, and the booking process can be so difficult that you won't mind paying a travel agent to take over. (Cathay Pacific's passes are actually sold only via agents.) To figure out if one is right for you, consider the following.
Idiosyncrasies Some passes, like Cathay Pacific's, include long-haul international flights in the purchase. Other passes strictly cover flights within a specified region. The Discover India Pass from Indian Airlines, for example, is good for unlimited flights within India for 7, 15 or 21 days, for $400, $630 and $895 respectively --but for your flight from the U.S. to India, you're on your own.
Prices, restrictions and parameters for passes vary greatly. The Caribbean Air Pass from BWIA West Indies Airways (from $450) includes flights to eight Caribbean destinations over a span of 30 days, but prohibits backtracking -- i.e., you're allowed to fly into each airport only once. Aerolineas Argentinas's South America Pass includes as many as 10 flights between Argentina, Brazil, Chile and Uruguay, but pass prices are based on total mileage. One itinerary, hitting Buenos Aires, Montevideo, Santiago and Rio de Janeiro, starts at just $550. The details on various flight passes can be found at bestfares.com (search "international air passes"); staralliance.com, which offers 11 passes around the world; and oneworld.com, which sells six passes.
Low-fare competition With the African Airpass from Star Alliance, all flights are routed through Johannesburg. Nonstop flights on low-fare carriers such as Nationwide Airlines may be more convenient and cheaper. Because discount-carrier routes are so plentiful in Europe, flight passes there rarely make sense. Search for low-fare carriers by region on attitudetravel.com.
Reservations Much of the appeal of an air pass is the idea of one-stop shopping. But you have to know exactly what you want: Unlike rail passes, which can be used without reservations, flight passes generally require that routes and dates be booked when you purchase.
Extra costs and blackouts The Malaysia Airlines AccessAsia Pass starts at $1,399, but taxes raise it by $300-$500 depending on your itinerary. Also, if you want to add cities not included in the pass, like Hong Kong or Ho Chi Minh City, for example, tack on at least $320. Sometimes pass prices are higher -- or blacked out -- during certain times of year. Cathay Pacific's pass was $350 extra for travel between May 19 and August 20 of 2006, and weekend flights add $100.
Free stopovers How much flying will you really be doing? Cathay Pacific always allows free stopovers in Hong Kong, so if all you want to do is visit the airline's hub for a few days en route to Bali, as one possibility, a standard ticket will probably cost less than a pass.
Availability Airlines often limit the number of seats that can be taken by flight passes; you can be shut out even if a flight isn't full. "If there are only one or two flights a day, your vacation can be dictated by availability," says Eva Robinson, a travel agent in Old Saybrook, Connecticut. Travel agents should know their way around this stuff, and typically charge $30 and up for their service.
Change policies Most airlines prohibit changing destinations once a pass has been purchased, though they'll usually let you switch dates: Cathay Pacific charges $100, while Aerolineas Argentinas and BWIA charge $25. Pass holders on Indian Airlines can change dates for free, provided they don't exceed the number of travel days allowed.
Frequent-flier miles Some passes, like the Star Alliance African Airpass, allow pass holders to earn miles, while others, such as Cathay Pacific's All Asia Pass, don't. In fact, Cathay Pacific won't even let frequent-flier members redeem miles when purchasing the pass.
Popular flight passes Pass: Aerolineas Argentinas South America Pass 800/333-0276, aerolineas.com.ar The Basics: Flights within South America priced by mileage, starting at $300 for up to 2,500 miles Heads Up: Date changes allowed for $25
Pass: Cathay Pacific All Asia Pass cathay-usa.com The Basics: Flight to Hong Kong and a choice of 18 Asian cities over 21 days, for $1,499 Heads Up: Join the free online club to save $200; booking through a travel agent is mandatory
Pass: BWIA West Indies Airways Caribbean Pass 800/538-2942, bwee.com The Basics: Flights between eight Caribbean destinations, from $450 Heads Up: Destination changes for $25; no backtracking allowed
Pass: Star Alliance African Airpass staralliance.com The Basics: Up to 10 flights in 17 sub-Saharan countries, at 15 cents per mile Heads Up: Only sold to passengers flying a Star Alliance partner into Africa
Note: This story was accurate when it was published. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.