Page 195 - Planning and Design of Airports

162 Airp o r t Pl anning

that one technique is better than another, then a simple average might
be used to develop the preferred forecast. If this is done in these
examples, then the preferred forecast for the year 2010 is about
2,000,000 annual enplaned passengers and in the year 2015 is 2,600,000
annual enplaned passengers.
The Federal Aviation Administration utilizes econometric models
to determine national forecasts of U.S. aviation demand. The FAA
Aerospace Forecast [8] provides a 12-year outlook and view of the
immediate future for aviation. It is updated in March each year and
includes aggregate level forecasts of the following:
• Passenger enplanements, revenue passenger miles, fleet, and
hours flown for large carriers and regional commuters
• Cargo revenue ton miles and cargo fleet for large air carriers
• Fleet, hours, and pilots for general aviation
• Activity forecasts for FAA and contract towers by major user
category

The FAA Long Range Aerospace Forecasts [9] is a long range fore-
cast that extends the 12-year forecast to a longer time horizon, typi-
cally for a period of 25 years. This forecast contains projections of
aircraft, fleet and hours, air carrier and regional/commuter passen-
ger enplanements, air cargo freight revenue ton-miles, pilots, and
FAA workload measures.
The success in applying mathematical modeling techniques to
ascertain the level of future activity depends to a large extent on the
certainty associated with the independent variables and the relative
influence of these variables on the dependent variable. Simple and
multiple regression analysis methods are often applied to a great
variety of forecasting problems to determine the relationships
between transport related variables and such explanatory factors as
economic and population growth, market factors, travel impedance,
and competitive forces. Table 5-2 lists many of the variables required
for various purposes in aviation planning studies.

Forecasting Requirements and Applications
The specific forecasting needs depend on the nature and scope of the
study being undertaken. The requirements for a state aviation system
plan are very different than those required for an airport master plan.
Facility planning requires projections of the parameters which deter-
mine physical design whereas financial planning requires projections
of the cost elements and revenue sources associated with physical
development. This section outlines the general forecasting require-
ments for various types of airport studies and discusses the more
common methodologies used to arrive at these requirements.