The larger the airport, the faster it is expected to grow in the next 15 years, the Federal Aviation Administration (FAA) predicts in its latest Terminal Area Forecast.

The nation's 33 largest hub airports are expected to grow at the fastest rate - 4.4 percent annually through 2010. The three fastest growing airports - Washington Dulles International Airport, 7.8 percent; Fort Lauderdale, 5.2 percent; and Philadelphia International Airport, 4.9 percent - are expected to grow faster than the rest because of traffic stimulation by low-cost carriers.

In forecasting the growth at individual airports, the FAA's long-term numbers are "independent of the ability of the airport and the air traffic control system to furnish the capacity to meet the demand." This important caveat would explain how Chicago O'Hare International is expected to grow at a pace so that it will still be the nation's second busiest airport in 2020. Since December, the FAA has cut the number of peak arrivals to reduce congestion. Last month, the FAA proposed extending this cap until 2008.

Not all the large hub airports are expected to grow. St. Louis International Airport is projected to have an annual negative 0.05 percent growth each year through 2020. Once a hub for American Airlines [AMR], St. Louis is now dominated by American Connection code-share partners. The FAA bases its projections on enplanements. An RJ obviously carries fewer enplaning passengers than an American Airlines mainline jet.

Another abandoned hub, Pittsburgh International Airport, is expected to grow by just a fraction of 1 percent each year. US Airways [UAIRQ] continues to reduce its presence at its long-time hub.

Of the 35 largest hub operations, all but 12 airports are expected to return to their 2000 peak levels of commercial operations by this year. Seventeen have already reached that point. Of the remaining 12 airports, 10 will eventually match their 2000 peak before 2020. St. Louis and Pittsburgh are not expected to reach that service mark until after 2020.

The 35 medium hubs, such as Hartford Bradley International Airport and Sacramento International Airport, are expected to grow at collective annual rate of 3.62 percent through 2010.

The 66 small hub airports, which include Atlantic City International Airport and Palm Springs International Airport, are expected to grow 3.69 percent a year through 2010.

The slowest growth rate is expected at the nation's 351 non-hub airports. The FAA predicts this class will grow just 1.9 percent annually through 2010. While a number of these airports are general aviation facilities, some, such as Toledo Express Airport in Ohio, Wilmington International Airport in North Carolina and Helena Regional Airport in Montana, are served by regional carriers.

Growth at these smallest airports will be faster than what the FAA has predicted, said Henry Ogrodzinski, president of the National Association of State Aviation Officials (NASAO). Representing the aviation departments of all states and territories, Ogrodzinski said these state agencies operate many more smaller airports than large hub airports.

These airports are expected to see growth in general aviation, air taxis and by scheduled carriers, he said.

Mainline aircraft, either by network carriers or low-fare carriers, are expected to produce "very little growth, if any." However, Ogrodzinski does expect to see more regional aircraft serving these smaller airports. Furthermore, he expects to see more carriers similar to Independence Air enter these smaller markets.

"There are a number of non-hub airports that you could not get to before Independence Air [FLYI]. I think you will see more of these kind of start- ups, which will stimulate traffic. Some will be successful and some won't," Ogrodzinski said. Additional traffic will be stimulated, he said, when JetBlue [JBLU] begins flying its new Embraer [ERJ] 190 fleet between business-intensive non-hub markets.

The real growth - and at this point unpredictable growth - will be the new generation of lightweight business microjets that are about to enter the market.

Proposed air taxi companies, such as Pogo, plan to operate on-demand flights to non-hub markets. Pogo plans to be "constantly in motion with each plane making three or four stops each day," he said. It has already ordered 15 Adams A700s, a six-passenger microjet. While technicially an on-demand operation, Ogrodzinski said these new air taxi operations will serve a number of small airports often enough to be predictable as a scheduled carrier.

The earliest projected delivery date for a microjet is mid-2005, while others are expected to be certified next year. The FAA projects that this niche will grow to 4,500 aircraft by 2016. By comparison, the FAA predicts there will be just shy of 4,000 RJs in operation by that same year.

Paul McKnight, the manager of air traffic forecasts at the airport consulting firm of John F. Brown, believes the FAA forecast is on target. At the same time, he questions just how much new traffic would be generated by the local business community that would drive the demand for business jet traffic. A plant manager traveling to the home office would not require an air taxi, McKnight said; however, a team from the home office traveling to a rural plant may use a taxi service. But the question remains just how many of these trips take place over a year, McKnight wondered.

One of the factors that comes into play with forecasting air traffic for the smaller markets is the cost of the airline ticket. There is price competition that has stimulated traffic in medium and larger hubs. "At the non-hubs, you have a lot of unaligned carriers or major affiliates. Would they lower the price to Podunk if they are the only game in town? Probably not. Hence, the FAA is making the assumption there will not be much price stimulation at these smaller airports," McKnight said.

>>Contacts: Henry Ogrodzinski, NASAO, (301) 588-0587; Paul McKnight, John F. Brown, (888) 403-3332.<<