# 9.2.1: The master plan


##### Definition 9.3: The Master Plan

The Master Plan is an official set of documents with information, studies, methodologies and performances to be carried out in the design and construction of a new airport or an important enlargement into an existing one.

In other words, a Master Plan is a guide for:

• Developing the physical facilities of an airport.

• Developing land adjacent to the airport and establishing access requirements.

• Determining the environmental effects of airport construction and operations.

• Proving the feasibility of the proposed developments through a thorough investigation of alternative options.

• Establishing a timeline for the improvements proposed in the plan.

• Establishing an achievable financial plan to support the implementation schedule.

More specifically, a Master Plan should include the following studies/documents:

• Study of the existing situation: physical medium data (topography, meteorology, etc.), socioeconomic data (demography, GPD, etc.), comparative studies with proximal airports, physical assets, etc.

• Demand forecast: flights and types of aircraft, including a complete long-term demand forecast.

• Demand/capacity analysis and facility requirements.

• Alternatives development.

• Preferred development plan

• Implementation plan

• Environmental impact assessment

• Stakeholder and public involvement

Figure 9.1: Master plan flowchart.

The master plan encompasses first a study of the current situation, including physical data (topography, meteorology, etc.), socioeconomic data (demography, GPD, etc.), comparative studies with nearby airports, etc. Aeronautical data such forecasted flights and types of aircraft, including a complete long-term demand forecast, are also needed. The forecasted demand is thereafter casted against the existing capacity (for which one should consider aircraft operations and an specific level of service for passengers). The capacity-demand imbalances raise the future necessities in terms of runways, taxiways, platform positions, terminal buildings, etc. Whether a new airport is needed or an enlargement of the existing one suffices should be analyzed. In either cases, different layout alternatives must be proposed. In case of the necessity of building a new airport, the key decision is to select the best emplacement. The Master Plan flowchart in Figure 9.1 illustrates the different processes that a typical Master Plan involves.

## Traffic forcast

The traffic prognosis is the key element within airport planning. It constitutes the baseline to define the facilities that are to be required together with the times at which those facilities will be necessary. It is provided in three different time horizons (short [5 years], medium [10-15 years], and long term [20-30 years]) and for three different scenarios (pessimistic, nominal, optimistic). Please refer to Exercise 1.1 as an illustrative instance.

The principal items for which estimates are usually needed include:

• The volume and peaking characteristics of passengers, aircraft, vehicles, and cargo.
• Number and types of aircraft needed to serve the above traffic.
• Number of general aviation aircraft and the number of movements generated.
• The performance and operating characteristics of ground access systems.

There are several forecasting methods or techniques available to airport planners ranging from subjective judgment to sophisticated mathematical modeling:

• Time series method.
• Market share method.
• Econometric modeling.
• Simulation modeling.
• Delphi method.

Econometric modeling represents the most sophisticated and complex technique in airport demand forecasting. Simple and multiple regression analysis techniques (linear and nonlinear) are often applied.

Multiple regression analysis can be regarded as an extension of simple linear regression analysis (which involves only one independent variable) to the situation where two or more independent variables are considered. The general form of a polynomial regression model for $$m$$ independent variables is

$Y = \beta_0 + \beta_1 X_1 + \beta_2 X_2 + \cdots + \beta_m X_m + \varepsilon,$

where $$\beta_0, \beta_1, ..., \beta_m$$ are the regression coefficients that need to be estimated. The independent variables $$X_1, X_2, ..., X_m$$ may all be separate basic variables, or some of them may be functions of a few basic variables. $$Y$$ represents an individual observation and $$\varepsilon$$ is the error component reflecting the difference between an individual’s observed response $$Y$$ and the true average response $$\mu_{Y|X_1, X_2, ..., X_m}$$.

## Demand and capacity analysis

The analysis of capacity in an airport must be done for each of its different components, since the bottleneck could be in any of them:

• Capacity of parking lots (parking positions).
• Capacity of the passenger terminal (pax/h).
• Capacity of ramp and apron (parking position).
• Capacity of taxiways (mov/h).
• Capacity of the runway (mov/h).

## Selection of the emplacement

The emphasis in airport planning is normally on the expansion and improvement of existing airports. However, if an existing airport cannot be expanded to meet the future demand or the need for new airport is identified in an airport system plan, a process to select a new airport emplacement may be required. For the selection of the emplacement one must take into account:

• The climatology (wind, fog, temperature, etc.).
• The topography (unevenness and slopes of the terrain).
• Obstacles in the surroundings (for safe taking off and landing).
• Intermodal connexions.
• Availability of terrains.
• Environmental impact.

Indeed, the master plan includes an environmental impact report of the operations in the selected emplacement. Economic studies in terms of operations and future development are also included.

Wind speed and direction: On the airport surface, the speed and direction of winds directly affect aircraft runway utilization. The best operational configuration is headwind: It allows an aircraft to achieve lift at slower ground speeds (with obviously greater true airspeeds) and shorter runway lengths. However, most of the times one would be affected by crosswinds to some extent. Lateral wind might be dangerous and sometimes operations would be cancelled if it exceeds determined safety thresholds (which depend on the aircraft type). ICAO provides requirements to runway design so that 95% of the annual wind conditions at the airport allow safe operations, which can be measured in terms of maximum permitted crosswind. According to ICAO, the crosswind component must not exceed:

• 37 km/h (20 kt) in the case of aeroplanes whose reference field length1 is 1500 m or over, except that when poor runway braking action owing to an insufficient longitudinal coefficient of friction is experienced with some frequency, a crosswind component not exceeding 24 km/h (13 kt) should be assumed;

• 24 km/h (13 kt) in the case of aeroplanes whose reference field length is 1200 m or up to but not including 1500 m; and

• 19 km/h (10 kt) in the case of aeroplanes whose reference field length is less than 1200 m.

Therefore, finding a location with low wind intensities (fulfilling ICAO restrictions) or with a clearly dominant wind direction is key. Indeed, as it will be described in Section 9.3.2, the orientation of the runway (or runways) will be partially driven by the blowing direction of the dominant winds. Therefore, starting 10-15 years prior the construction of the airport, a detailed study on the wind patterns is carried out to statistically select the most appropriate runway’s configuration. Wind intensities and directions are used to complete a so-called wind rose diagram. Please, refer to Exercise 1.2 as an illustrative instance.

Orography: The orography of the site is also key for two fundamental reasons: first of all, ICAO establishes requirements in terms of maximum slopes for runways and taxiways; second, ICAO also establishes requirements in terms of obstacles to facilitate the design of more efficient and safer departure and arrival procedures, for which ICAO specifies a set of obstacle limitation surfaces that must not be violated by orographic accidents (e.g., mountains) or human-made buildings:

• Outer horizontal surface and inner horizontal surface.
• Conical surface.
• Approach surface and Inner approach surface.
• Transitional surface and Inner transitional surface.
• Balked landing surface and take-off climb surface.

Therefore, selection a relatively flat emplacement would reduce the cost of the construction of the airport (since less terrain movement would be needed to make it flat). Also, selecting an emplacement with relatively few obstacles would not limit the possible directions of the runway.

Environmental issues: The construction of a new airport (also the enlargement) of an existing one implies a tremendous environmental impact, associated to: social factors such as land development, displacement and relocation, parks, recreational ares, historical places; ecological factors such as wildlife, waterfowl, flora, fauna, endangered species, and wetlands and coastal zones; and pollution factors such as air quality, water quality, and noise.

1. please, refer to Definition 9.5.

9.2.1: The master plan is shared under a CC BY-SA 3.0 license and was authored, remixed, and/or curated by Manuel Soler Arnedo via source content that was edited to conform to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.