1. What is an Airspace Concept?
An Airspace Concept is an outline of the intended framework of operations within an airspace. Airspace concepts are developed to satisfy explicit strategic objectives such as improved safety, increased air traffic capacity, improved efficiency, more accurate flight paths and mitigation of environmental impact. Airspace Concepts can include details of the practical organization of the airspace and its users based on particular CNS/ATM assumptions; for example, ATS route structure, separation minima, route spacing and obstacle clearance.
Once fully developed, an airspace concept describes the target airspace organization and operation in detail, ensures that it addresses the strategic objectives, and makes sure that all CNS-ATM enablers as well as assumptions are captured. In fact, the airspace concept is no more than a master plan or schema of the intended airspace design and its operation
2.  Why do an Airspace Concept?
Developing an Airspace Concept provides a structured and systematic way of determining what is to be achieved in an airspace, and how it can be achieved.   It also ensures that the management of air traffic is improved. The elaboration of an Airspace Concept helps to ensure that the goals (expected benefits) of planned airspace structure, routes and IAP implementations are clearly stated and that the objectives of the airspace change are met. The process of developing an Airspace Concept helps to guarantee that the means chosen to achieve those benefits are appropriate to the goals as well as feasible within the resources available to the particular airspace system.
3.  Who develops the Airspace Concept?
Development of an Airspace Concept is a team effort by representatives of various organizations and technical specialties. The particular composition of an Airspace Concept development team depends on the scale and nature of the project.  For example, if a fairly simple terminal concept with a single set of arrival, approach and departure procedures is envisaged, a few experts from the ANSP (including a trained PANS OPS procedure design specialist), the civil aviation regulator, the airport operator and, ideally a representative of the operators may be sufficient.  A more extensive Airspace Concept, such as the introduction of a new runway into that same terminal airspace, or a broader plan involving terminal and enroute airspace, might involve additional personnel (e.g. safety management system experts, simulation studies experts, additional operator representatives, environmental personnel, etc).
An Airspace Concept development team would usually be led by airspace planners from the ANSP. If the ANSP does not have an Airspace Planning unit, knowledgeable air traffic managers would be logical choices to lead the effort.
However, it is not a hard and fast rule that the development of an Airspace Concept must be led by an airspace planner from the ANSP.  A knowledgeable, proactive and dedicated individual with a sound understanding of air traffic management and airspace organization along with appropriate support from participating agencies is the fundamental need for a successful Airspace Concept development effort.
4.  What resources are needed?
Resources needed in developing an Airspace Concept fall into four categories.  The amount of each depends on the complexity of the project. Developing an Airspace Concept requires:
a)  PEOPLE – with appropriate expertise in (or at least a good working knowledge of) airspace planning, air traffic management/control, procedure design, (ANSPs); operator approvals, airworthiness (regulators); fleet capabilities (operators, general aviation, business aviation, military aviation representatives), etc
b)  TIME –  Development of an Airspace Concept is not accomplished in a single meeting.  It includes exploring the needs of various airspace stakeholders, reaching agreement on goals, identifying current ground and airborne equipment limitations, conducting traffic flow analyses, and a number of other activities to ensure development of an Airspace Concept that meets system needs and is feasible to implement.
c)  MONEY – While PBN implementation is mainly about procedures (instrument procedures, aircrew procedures, ATC procedures, flight dispatch procedures, data quality and data base maintenance procedures, etc) rather than purchase and installation of costly new equipment or systems, it does have costs, which are usually significant enough that budgetary resources must be specifically allocated.  Initial development of an Airspace Concept may be feasible with existing resources, but the detailed assessment of costs associated with implementation of the Airspace Concept should be made as part of the overall program planning for PBN implementation. Costs include (but are not limited to) education and training (regulators, operators, ATC, procedure designers, etc), establishment and sustainment of robust airworthiness, operations approvals, data quality techniques, changes to ATC automation, flight validation, possibly new NAVAIDS (DMEs), and so on.
d)  TOOLS - Depending on the scope and complexity of the Airspace concept several tools can support the validations and assessment of the present and target Airspace concept. The following tools are in use by EUROCONTROL and the FAA;
·        Airspace modeling and design tools
These types of tools are used for airspace design purposes (2D&3D) for visualization, testing and analyzing of various airspace organization options. The data can be exported to fast and real time simulators.
·        Fast time simulation tools
Fast time simulators are used to calculate the capacity of a certain airspace based on the workload induced to the sector controllers by a given traffic sample. This means that a detailed analysis of the analysed airspace is performed, including ATC/ATM procedures, controller working methods and practices and any local particularities that might influence sector capacity. The results of the fast time simulations are often used for real time simulations.
·        Real time simulation tools
In order to validate a new airspace concept a real time simulation is the most realistic way of assessing what the benefits accrue over present operations. In the simulation the present operations, also referred to as the reference scenario, are used as bench mark in order to assess the perceived benefits in comparison to the target airspace concept.
·        Flight simulators
Flight simulators can be used to check the flyability of certain procedures and get further data on fuel efficiency, cockpit workload and other cockpit related issues.
5. What is the critical starting point of developing an Airspace Concept?
The most critical part of developing an airspace concept is setting the appropriate objectives and scope from the outset. This is of crucial importance as it enables the project team to remain focused and the budget to be managed within the set timeframe. Most projects which fail to meet the intended goal do so because of poorly defined scope and objectives. (Because the number of tasks continuously changes or increases, which results in not being able to finish the project within the set timeframe and budget, thereby not meeting the intended goal).
6. How is an Airspace Concept documented?
An Airspace Concept can be contained in any document format. Configuration control of the “Master” Airspace Concept document should be maintained by a single designated office or official, since it is the source document for the implementation planning that will follow.
7. When is it appropriate to start developing an Airspace Concept?
Development of the Airspace Concept should generally begin when the need for change in airspace is identified.  However, if there is a great deal of uncertainty in the current situation, it may be more productive to delay work on development of the Airspace Concept until the situation is more stable. Such a delay would generally be for no more than a period of several weeks.
8. How is development of an Airspace Concept started?
When the objective and scope are set, the present operations need to be “captured” (i.e. described in the document in detail) and assessed. This data collection exercise is a realistic reflection of present day operations, which might be somewhat different than described in the Letters of Agreement or Aeronautical Information Publication.  This current operations capture can be called the “reference scenario”. In describing the Reference Scenario, a description of what works and what needs to be improved is assessed. It is important to keep in mind that without the development of the reference scenario, it is neither possible to compare the target airspace concept to the benchmark nor to quantify the improvements anticipated. The data collection is done over several days, possibly during a workshop with all involved parties. The use of Airspace modeling tools can be of great benefit to visualize and identify areas of great complexity and also identify the positive elements of present day operations.
9.  Once the Airspace Concept is developed and documented, what comes next?
Generally, laying out an outline implementation plan is included in the Airspace Concept. Once the Airspace Concept is completed, laying out a detailed program plan for the specific implementation(s) in the agreed-upon Airspace Concept would be the next step.  ICAO has provided some sample action plans, both domain-specific (enroute, terminal, approach) as well as a comprehensive example, which could serve as starting points for the team charged with implementing the Airspace Concept. An ICAO sample Action Plan should be considered as a starting point for a PBN implementation. It can be adapted as needed to the specific circumstances of a project. The steps are not always conducted in strict sequence, and certain steps may be conducted on a recurring basis as the project progresses. The steps and the sequence in which they are performed in the project should be evaluated by the implementation team on the basis of their experience and judgment.