Guidebook for Preparing and Using Airport Design Day Flight Schedules (2016)

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3 C H A P T E R 1 This chapter introduces and defines DDFSs, discusses their benefits, and describes the organization of the guidebook. The intent of this guidebook is to provide airport planners and operators with a ready refer- ence for effectively preparing and using DDFS for their analysis of future airport activity and its effects. The guidebook is designed to help aviation professionals exploit the advantages and mitigate the disadvantages of DDFSs to help them prepare DDFSs accurately and efficiently, use them effectively and to their full potential, and identify alternatives to a DDFS when appropriate. 1.1 Definitions A DDFS is essentially a detailed snapshot of existing or forecast activity at an airport or in an airport system and can serve many roles. It can be a market assessment that illustrates passenger flows to other communities. It can be an airline business plan that demonstrates the role of an airport in an airline’s route system, and how the airline moves passengers within its system. It can also be an airport facility planning tool that provides a mechanism for planning and man- aging runways, gates, terminals, roadways, and other airport facilities by level of activity and time of day. A DDFS provides an unparalleled degree of detail essential to analyzing complex issues and developing solutions for those issues. DDFSs are referred to by many names, including event files, gated flight schedules, planning day schedules, or hypothetical design day activity. They can be designed in several ways depending on the type of analysis, but are distinguished in that they discretely represent each flight in a day, indicating type of operation (arrival/departure) and specific time of operation. Many DDFSs also include equipment type, gate assignment, origin and destination (O&D), and arrival/departure pairings. Some DDFSs also include ground movements, such as the use of airfield penalty boxes and towing from a gate to a RON hardstand. When used for passenger facility analysis, DDFSs can include the number of passengers assigned to each flight, potentially identifying O&D and connecting passengers. In this guidebook, a DDFS is defined as a constructed schedule showing individual aircraft arrivals and departures by time of day and aircraft type that can also show airline, O&D, and the number of passengers associated with each flight, depending on the level of detail required. Although a DDFS typically includes an entire design day, it can be restricted to a peak period of interest if a full day is not required for a particular project. It may be used by airport staff, or by consultants on behalf of airport operators, for operational or facilities planning analyses or for simulation modeling purposes. Introduction and Overview A DDFS provides unparalleled detail essential to analyzing problems and developing solutions for complex airport issues. A DDFS is defined as a constructed schedule showing individual aircraft arrivals and departures by time of day and aircraft type that can also show airline, origin/destination, and passengers associated with each flight, depending on the level of detail required.

4 Guidebook for Preparing and Using Airport Design Day Flight Schedules A DDFS is contingent on selection of a design day. The definition of the design day depends on the purpose of the analysis. For most planning, the design day is intended to represent a busy day that characterizes the ability of a facility to provide adequate capacity and service levels most of the year while avoiding the cost of building for the single busiest day of the year. The trade-off between capacity/service level and cost may vary by facility. For most environmental analyses, the design day is defined as an average annual day. 1.2 Guidebook Audience There are two main audiences for this guidebook, users of the DDFS and preparers of the DDFS. Users need to have a basic understanding of a DDFS, including its advantages and limita- tions. Users should be able to determine when a DDFS is needed, how it should be scoped, and how the results should be communicated, but do not need to immerse themselves in the details of DDFS preparation. Preparers of the DDFS should also be knowledgeable of DDFS uses, but their main focus is on constructing the DDFS. Preparers need to be familiar with the many intricacies and nuances involved in preparing a DDFS and how they may affect the projects or issues that the DDFS will be used to evaluate. Later in this overview and at the beginning of each chapter, readers are informed as to whether the material is directed to the user audience or the preparer audience. 1.3 Guidebook Organization and Summary To the extent possible, this guidebook features a modular organization. The guidebook is organized to enable quick navigation to the area of interest. The chapters of the guidebook are organized as follows. Chapter 2: What Is a DDFS (users and preparers) describes the DDFS, its key elements, and current uses. Some DDFS elements are common to all DDFSs, whereas others are optional depending on the intended DDFS use. Key elements are listed in Table 1.1. There are two main audiences for this guidebook, users and preparers. Reference Number/Record Idenfier Arrival/Departure Designaon Arrival/Departure Pairing Acvity Category Flight Time Day of Week Airline Flight Number Gate Assignment Remain Overnight Status Domesc/Internaonal/Precleared Designaon Origin/Desnaon Aircra  Equipment Type Seats Load Factor Enplaned/Deplaned Passengers O&D Percentage Originaons/Terminaons/Connecons Runway Use Designaon Arrival/Departure Fixes Table 1.1. Elements of a DDFS.

Introduction and Overview 5 The key elements will vary depending on the intended use of the DDFS. For example, air- field analyses will not require passenger loading information, such as enplaning and O&D passengers by flight. In general, DDFSs are used when detailed analysis is required for: (1) planning, design, and operation of airports when complex master planning alternatives and facilities need to be evalu- ated; (2) decision support to resolve airport issues and formulate strategies; and/or (3) program- ming, design, and environmental analysis of new large projects. Often these analyses involve airfield or terminal building simulation modeling that requires inputs at an individual flight level of detail. Airport operators are also increasingly using real-time or short-term DDFSs to address operational and management issues, such as gate allocation, staffing, and noise monitoring. For more detail, click to access Chapter 2. Chapter 3: When Should a DDFSs Be Used (primarily users) provides guidance on when to apply a DDFS, with a focus on the type of issue being analyzed, the size and role of the airport, available resources, and alternative analytical approaches. The decision regarding whether or not to prepare and use a DDFS will depend on the factors listed in Table 1.2. In general, DDFSs are used extensively to assist in the planning of major airfield and termi- nal capacity projects. To a lesser extent, they are used in landside and environmental planning. Short-term DDFSs are increasingly being used in managing airport and airport-related opera- tions. For more detail, click to access Chapter 3. Chapter 4: Which Elements Need to Be Included in a DDFS (primarily users) provides guid- ance on the recommended level of DDFS detail, specifically airline, aircraft, market, gate assign- ment, and passenger load information, which depends on the type of facility being analyzed, as well as the audience and stakeholders, the purpose of the analysis, and the available resources (see Table 1.3). Under some limited circumstances, a partial DDFS that includes the anticipated peak period and the times immediately preceding and following the peak period can be used instead of a DDFS for a full design day. Partial DDFSs may be appropriate at small uncongested airports where the peak activity period is clearly defined and carryover delay and recovery times are not an issue. Partial DDFSs are best used to examine requirements for facilities closely tied to peak passenger or aircraft flows. Some facilities, such as curbsides, accommodate activity peaks that are offset significantly from the at-gate peaks and may be influenced by off-peak activity flows in Airport Size Airport Role Airline Hub Role Airport Constraints Paerns of Scheduled Acvity Type of Project Capacity Issues Likelihood of Detailed Follow on Planning Complexity of Project Planning Tools to Be Used Compeng Demands within Airport Degree of Scruny Project Cost Available Resources Expected Controversy Table 1.2. Factors determining the need for a DDFS.

6 Guidebook for Preparing and Using Airport Design Day Flight Schedules ways not readily apparent. The requirements for other facilities, such as gates, may be greatest at off-peak times, such as late at night. In these instances, partial DDFSs are not appropriate. For more detail, click to access Chapter 4. Chapter 5: How to Scope a DDFS (users and preparers) provides guidance on determin- ing the scope of the effort, if a DDFS is useful or appropriate, which DDFS elements should be included, and appropriate time horizons. As illustrated in Exhibit 1.1, it is the first step in pre- paring a DDFS. For more detail, click to access Chapter 5. Chapter 6: How to Prepare a DDFS for Base Year and Future Conditions (primarily pre- parers) provides guidance on preparing a DDFS, including defining key parameters, describing the steps involved in the preparation, and applying the results. Exhibit 1.1 shows a generalized schematic diagram of the DDFS process. Parameters that will govern preparation of the DDFS need to be defined, as they help deter- mine the required data inputs. Among the most important of these is the design day definition. If the DDFS is being prepared for future conditions, assumptions regarding future operating policies and physical constraints should be determined. These can include noise curfews; demand management policies, such as slot restrictions; and physical gate, airspace, or airfield capacity constraints that cannot or are not expected to be mitigated. In addition, if the DDFS is intended to be used to model a future airport layout, pertinent information, such as gate and concourse locations and capabilities, should be determined. Construction of a DDFS involves market and fleet mix projections assembled to generate a design day estimate of arrivals and departures by aircraft types. The market and fleet mix projec- tions are sometimes available from an annual activity forecast, but often need to be independently Type of Analysis DDFS Elements Needed Airside Planning The most important elements are flight mes, aircraft types, and arrival/departure designaons. Passenger related informaon, such as the number of passengers per flight, is not required. Terminal Planning Terminal planning, especially planning for facilies related to passenger processing, usually requires the most DDFS detail. In addion to flight mes and aircra types, the numbers of passengers associated with each flight and segmentaon by O&D or connecng status are required. Landside Planning Landside planning typically focuses on vehicle flows, which are derived from passenger flows. Therefore, the DDFS passenger data typically used for terminal planning is required, but aircraft details are not required. Environmental Planning Environmental planning mostly involves noise and air quality analyses, although the modeling tools used for these analyses may differ depending on the focus of the analysis: airfield planning or landside planning. A DDFS level of detail is oen not required. If the environmental analysis is related to aircra operaons, the DDFS level of detail required for airside planning is sufficient. If the environmental analysis is focused on vehicular traffic, the level of detail required for landside analysis is more appropriate. Operaons and Management DDFSs used for operaons and management tend to be real me or short term (1 to 2 years out at most) and are somemes prepared and updated using automated methods or third party vendors. When DDFSs are used for airfield or gate management, the most important elements are flight mes, aircra types, and arrival/departure designaons. When DDFSs are used for terminal facility management, esmates of the numbers of passengers associated with each flight are also required. Table 1.3. DDFS elements needed by type of analysis.

Introduction and Overview 7 calculated. Flight times are estimated for each aircraft arrival and departure and arrivals and departures are paired or matched. Once flight times are estimated, passenger loads, gates, and flight tracks can be assigned if necessary. For many airfield simulation analyses and for terminal planning, arriving aircraft need to be assigned to gates. Factors that should be considered include existing and planned gate layouts, gate capabilities for accommodating different types of aircraft, gate assignment policies (exclu- sive, preferential or common-use), buffer time between a departure and arrival at the same gate, and balancing of operations among gates. When DDFSs are used for terminal and landside plan- ning, they must be translated into passenger flows. This requires estimating enplaned passenger loads and O&D/connecting passenger splits for each flight. At spoke airports, a generic O&D/ connecting passenger split may be sufficient, but at airline hubs, the O&D/connecting passenger split will be markedly different for the hubbing airline. DDFSs prepared for large airports tend to be focused on scheduled passenger airline air- craft operations because they often represent the largest category and affect critical facilities, such as the terminals, gates, and curbsides. However, if intended to address airfield issues, a DDFS should include nonscheduled aircraft categories, such as charter, air taxi, all-cargo, general aviation (GA), and military operations. In a DDFS, these operations are typically represented by a selected sample of daily activity representing a normal distribution of operations activity. Data User Parameters Q ua lit y Co nt ro l DE SI GN DA Y FL IG HT SC HE DU LEMarket Assumpons Fleet Mix Gang Assumpons Cargo, General Aviaon, and Military Operaons Constraints Esmated Airfield, Terminal, Landside, Environmental, and Operaonal Requirements Load Factors O&D/ Connecng Split Flight Times St ak eh ol de rC oo rd in a on /C om m un ic a on Aircra, Passenger, and Vehicle Distribuons Scoping Exhibit 1.1. General DDFS preparation process.

8 Guidebook for Preparing and Using Airport Design Day Flight Schedules DDFSs are inherently detailed and their preparation involves substantial individual judgment in the selection of new markets, flight times, arrival/departure pairings, and other elements. As a result, there is a potential for both error and bias and quality assurance is an important con- sideration. For more detail, click to access Chapter 6. Chapter 7: How to Apply DDFS Outputs (primarily preparers) provides guidance on how to modify DDFS output, if necessary, for application in airfield, terminal, landside, and envi- ronmental planning and operations and management (see Table 1.4). For more detail, click to access Chapter 7. Chapter 8: How to Address Risk and Uncertainty with DDFSs (users and preparers) pro- vides recommendations on how to evaluate and manage the uncertainty inherent in all future DDFSs. Sources of uncertainty in future DDFS and the annual activity forecasts upon which they are based include: • Inputs such as projections of economic growth or fuel and other costs; • Assumptions on future industry changes, such as those related to airfares, types of air service, and competitive factors; • Statistical modeling error; and • Disruptive events, such as the September 11, 2001, terrorist attacks. Statistical methods for quantifying uncertainty are used to estimate how an actual future value of a forecast metric (for example, passengers) is likely to deviate from the predicted value. By measuring historical variations in activity from the long-term average, the most likely distribu- tions of activity around the long-term average can be estimated and applied to forecast values. These distributions are often described as confidence intervals, discussed further in Chapter 7. Some methods of addressing DDFS uncertainty are listed on Table 1.5. For more detail, click to access Chapter 8. Type of Analysis Applicaon Airside Planning DDFSs can be directly incorporated into airfield and airspace simulaon and spreadsheet models. They can be used to idenfy new runway or taxiway/holding pad requirements, esmate capacity or delay, or idenfy hot spots that could represent safety concerns. DDFSs can also be aggregated into hourly aircra distribuons for input into spreadsheet models to esmate capacity and delay. Terminal Planning DDFSs can be directly incorporated into terminal simulaon models or aggregated into hourly passenger distribuons that can be customized to reflect alternave design day definions or peak period acvity levels for use in spreadsheet models. Landside Planning DDFSs can be aggregated into O&D passenger distribuons for conversion to vehicle distribuons using modal split and lead and lag me assumpons. The vehicle distribuons can then be used as input to landside simulaon models or simpler landside spreadsheet models. Environmental Planning DDFSs can be incorporated directly into the AEDT or aggregated into day/night and stage length categories for AEDT processing. DDFSs can also be directly incorporated into the AEDT for aircra related air quality dispersion analysis or used indirectly to esmate ground vehicle emissions. Operaons and Management DDFSs are used directly to assist in airline and airport operaons and gate management. If staffing requirements are related to airfield or terminal building operaons, intermediate aircra or passenger distribuons developed from DDFSs can be used to generate staffing requirements. Table 1.4. Application of DDFS output.

Introduction and Overview 9 Chapter 9: How and When to Communicate DDFS Results (primarily users) provides guid- ance on how to best communicate the assumptions, results, and uncertainty associated with DDFSs and when and how often to engage stakeholders in the process. Coordination and communication are important to a successful DDFS: defining the prob- lem to be solved, obtaining meaningful input and reviews by stakeholders, and identifying critical elements. This coordination and communication process becomes most critical once DDFS results are produced and applied. In most instances, reporting and coordination of DDFS results have two distinct target audiences: (1) senior airport management and stakeholders and (2) technical airport staff and consultants. Senior airport management and stakeholders will make decisions based on analysis results. They need to be involved in the definition of the issue/problem and the reason for preparing the DDFS and they need to understand the: • Rationale for the DDFS preparation approach used; • Key assumptions that will likely influence the results; and • Areas of uncertainty and risk in the DDFS results. Documentation provided to senior management and stakeholders should be straightforward, nontechnical, and as concise as an executive summary. Technical airport staff and consultants need additional detail to fully understand the results, assumptions, and decisions so that a documentation trail is available to use in follow-on studies and analyses, both in the near term and for future updates. While the level of detail and docu- mentation will vary from airport to airport and project to project, at a minimum, assumptions regarding critical DDFS factors need to be transparent. One of the most important messages that needs to be relayed to all audiences is the “point- in-time” nature of the DDFS preparation process and the inherent uncertainties and related risks of a dynamic aviation industry. This issue is one of the challenges of the DDFS process and needs to be clearly explained to establish the credibility of the DDFS results, which would be used for various facility analyses. For more detail, click to access Chapter 9. The appendices include a DDFS case study (Appendix A) with exam- ples, more detailed discussion of the stability and predictability of DDFS factors (Appendix B), additional discussion of uncertainty (Appendix C and Appendix D), quality control recommendations (Appendix E), a list of data sources (Appendix F), and a glossary (Appendix G). Randomly adjust DDFS elements, such as arrival or departure mes, to test the sensivity of planning outcomes. Develop forecast scenarios for DDFSs, which could generate a wealth of detail, but could also be cost prohibive. Calculate confidence intervals for aggregate DDFS results to esmate the uncertainty associated with measures of airfield capacity, gate requirements, and peak passenger flows. Prepare Monte Carlo simulaons in which probability distribuons are idenfied for forecast input factors and parameters, and mulple iteraons are then run with the inputs and parameters randomly generated based on the probability distribuons. Prepare risk registers to address low frequency, high magnitude risks that are difficult to define using probability distribuons. Table 1.5. Methods of addressing DDFS uncertainty. One of the most important messages that needs to be relayed to all audiences is the point-in-time nature of the DDFS preparation process and the inherent uncertainties and related risks of a dynamic aviation industry.

10 Guidebook for Preparing and Using Airport Design Day Flight Schedules Several other ACRP publications supplement the guidance herein. In particular, the reader is encouraged to refer to: • ACRP Report 25: Airport Passenger Terminal Planning and Design, Volumes 1 and 2 (2010), provides guidance on applying DDFS inputs for terminal planning. http://onlinepubs.trb. org/onlinepubs/acrp/acrp_rpt_025v1.pdf and http://onlinepubs.trb.org/onlinepubs/acrp/ acrp_rpt_025v2.pdf • ACRP Report 40: Airport Curbside and Terminal Area Roadway Operations (2010), provides guidance in applying DDFS-derived inputs to evaluate airport roadway and curbside operations. http://onlinepubs.trb.org/onlinepubs/acrp/acrp_rpt_040.pdf • ACRP Report 76: Addressing Uncertainty about Future Airport Activity Levels in Airport Decision Making (2012), provides in-depth guidance for incorporating uncertainty into airport forecast- ing and planning. http://onlinepubs.trb.org/onlinepubs/acrp/acrp_rpt_076.pdf • ACRP Report 79: Evaluating Airfield Capacity (2012), provides guidance on applying DDFS inputs for airfield planning. http://onlinepubs.trb.org/onlinepubs/acrp/acrp_rpt_079.pdf • ACRP Report 82: Preparing Peak Period and Operational Profiles—Guidebook (2013), provides alternatives to DDFSs for estimating peak activity levels. http://onlinepubs.trb.org/online pubs/acrp/acrp_rpt_082.pdf