Courier flights, in their heyday, saved budget travelers thousands of dollars on overseas fares.
Travelers took courier flights between North America, Europe or Asia. They spent a small percentage of the prevailing fare on these one-way trips, and frequently received a similar deal on the way home.
Because companies must get documents or small product shipments overseas and through customs in a hurry, these courier services were considered crucial.
In essence, the traveler's baggage allotment was sold to the company making the shipment. The traveler got a greatly reduced fare as a result.
To some, it sounds like the stuff of James Bond or "Mission: Impossible." But courier trips, while quite rare today, are completely legal. Most of the time, the traveler never sees the item he or she is delivering.
The courier plan worked because most airline baggage drifts through customs with little or no delay. With air cargo, day- or week-long delays were common.
Courier companies, which match willing travelers with companies seeking quick delivery, appeared on the Internet offering great deals to budget travelers with flexible schedules. There is nothing secretive about the arrangements. The courier is "paid" with a greatly discounted airline ticket. These opportunities still exist, but they are becoming increasingly difficult to find.
Why is this so?
Unlike the late 1990s and early 2000s, when these flights became popular, air cargo companies now have much larger fleets and more sophisticated handling services that work with customs agencies to speed deliveries.
Memphis-based Federal Express, for example, issued a news release in August 2007 describing upgrades resulting in a 50 percent increase of daily delivery capacity from London to the United States.
According to the release, this one upgrade added up to a "20 percent daily capacity from Europe to United States."
Such investments are not made without due consideration of what the competition is doing. Other companies are making similar improvements. In short, the air cargo industry has become much stronger and better prepared for speedy delivery than it was in decades past.
Airfare competition also has become more intense during that time. Customs requirements and procedures underwent a major overhaul in most countries following the 9/11 terrorist attacks. The list of air courier companies offering cheap flight opportunities has dwindled as a result.
A word of warning: You should carefully consider whether it is worthwhile to purchase a membership with any organization offering airfare discounts. Are the prices reliable? Can cheaper flights be found elsewhere? Have I read the fine print? Now more than ever, you should approach all air courier offers carefully.
Your responsibilities as a courier are limited: show up at the airport on time, and meet a representative at the destination airport. Once through customs/immigration, your obligation usually is finished.
Rookie couriers should brush up on packing skills for a budget trip, because in many cases, you'll use up your luggage allotment transporting the shipment.
One carry-on bag might be your limit.
More bothersome are the schedules, which are left to the will of the company you'll represent. You must have a flexible timetable for travel, although sometimes assignments can be arranged well in advance.
Don't be too picky about your destination, either. For example, if you really want to go to Brussels, you might land in Paris and take a short train trip into Belgium. The money saved on airfare might pay for a lot of train tickets.
Other drawbacks: if you're traveling with a partner, it's highly unlikely you'll be able to share the flight unless the partner pays full fare. It could be tough to find two courier assignments to the same destination on the same day.
Most assignments are one-way. Arrangements to get back home could be tricky. If you're a drinker, alcohol on the plane is a no-no for couriers.
You must be at least 18 years old and a valid passport is required. Domestic courier flights do not exist.
One final thought: it's natural to ask if there is any risk of being an unsuspecting drug smuggler. Sometimes, when trade secrets are involved, you might not receive a detailed description. But reputable companies will provide you with documentation of contents for customs.
The air courier option is far less available and attractive than in years past. It is seldom a practical answer to the need for a cheap overseas flight.