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73 C H A P T E R 7 This chapter describes how to apply DDFS outputs to assist in airside, terminal, and landside planning, in environmental analysis, and for operations and management. It is intended primarily for DDFS users. As noted in Chapter 3, DDFSs have many uses. Some uses incorporate DDFSs directly as inputs while other uses require some post-processing. Exhibit 7.1 provides a general schematic of how DDFS outputs are used for airport planning and operations. 7.1 Airfield and Airspace Planning DDFSs, with some minor changes in format, are often used as direct inputs for airfield and airspace simulation and spreadsheet models. Runway preferences and arrival/departure fixes for each flight may be set as part of the DDFS or later, when establishing rules for the simulation runs. The results may be used to identify new runway or taxiway/holding pad requirements, estimate capacity or delay, or identify hot spots that could represent safety concerns. DDFS results may also be aggregated into aircraft distributions or design day profiles. These are hourly listings of airport operations, segmented by arrivals and departures, which can be used as inputs for simpler spreadsheet models to estimate capacity and delay. Once converted, design day profiles can be modified using tools such as the ACRP Report 82 Operations Toolbox to represent alternative design day definitions or even different activity lev- els. These adjustments are appropriate if there is reason to believe that the general distribution of activity throughout the day (the shape of the profile) will not change significantly. ACRP Report 79: Evaluating Airfield Capacity http://onlinepubs.trb.org/onlinepubs/acrp/ acrp_rpt_079.pdf provides comprehensive guidance on how and when to use DDFS output in capacity and delay analyses. 7.2 Terminal Building Planning The flight-by-flight passenger information in a DDFS can be directly entered into terminal simulation models. More often, the results are aggregated into passenger profiles, segmented by time of day and in accordance with the facility being analyzed (terminal, concourse, etc.). In these instances, software such as the ACRP Report 82 Passenger Toolbox can be used to process DDFSs into user-defined design day distributions or peak period activity levels and can also be used to adjust the results to represent alternative definitions of the design day or different forecast activity levels. Again, these adjustments are appropriate only if there is reason to believe that the general distribution of activity throughout the day will not change significantly. How to Apply DDFS Outputs
74 Guidebook for Preparing and Using Airport Design Day Flight Schedules Aircra Distribuons Vehicle Distribuons Passenger Distribuons Future Landside Requirements ⢠Curbside ⢠Roadway Future Terminal/ Gate Requirements Airport Operaons and Management Future Airfield Delay/ Capacity DDFS with Gang Assignments (See Exhibit 6.5) DDFS with Passengers (See Exhibit 6.7) DDFS (with Flight Tracks) Airfield/ Airspace Simulaon Models Airfield/Airspace Spreadsheet Models Runway/ Taxiway Requirements Terminal Simulaon Models Terminal Spreadsheet Models Intermediate Preparaon Step Output Legend Staffing Models Landside Simulaon Models Landside Spreadsheet Models Staffing Requirements Noise/Air Quality Models - Airside Environ- mental Migaon Noise/Air Quality Models - Landside Exhibit 7.1. Use of design day flight schedules.
How to Apply DDFS Outputs 75 Most DDFSs tie enplaning passenger activity to scheduled gate departure times of the flights with which they are associated. However, departing passengers require time to check in, pass through security, and navigate through the airport. Therefore, peak flows at depart- ing passenger facilities occur in advance of the enplaning peak measured in a DDFS. The extent of this lead time (sometimes described as show-up time) will depend on the configu- ration of the airport, the queues at the various departing passenger facilities, security restric- tions, whether the flight is domestic or international, airline policies such as cutoff times, and the extent to which passengers build in a buffer time to allow for unforeseen delays. The lead time is not constant; it varies by time of day and by type of passenger. It also varies by airport: passengers at large airports tend to allow longer lead times than those at small airports. The lead time is often described as a probability function where y percentage of passengers show up at the terminal x minutes before scheduled departure time (see Exhibit 7.2). As a result of the combination of the lead time and probability distribution, the timing and intensity of the peak period flow at a given departing passenger facility may not exactly match the enplaning peak. A similar phenomenon occurs with arriving passengers. They need time to deplane, in some cases go through Customs or to baggage claim, and then proceed to their selected ground trans- portation mode. These lag times trail the scheduled arrival times in the DDFS. Again, because of this lag, the timing and intensity of the peak period flow at a given arriving passenger facility may not exactly match the deplaning peak. The ACRP Report 82 Passenger Toolbox http://onlinepubs.trb.org/onlinepubs/acrp/acrp_ rpt_082.pdf provides a method of adjusting DDFS output for lead and lag times. However, the user must provide the lead and lag time distribution curves, which are typically only available from passenger surveys. ACRP Report 26: Guidebook for Conducting Passenger User Surveys pro- vides guidance on collecting this type of data. An example of how lead distribution curves were used to modify DDFS results can be found in Appendix A. Click here to access Section A.11 Application of Results. Once the DDFS outputs have been processed into design day profiles or peak period activity levels with appropriate lead and lag time distributions, the data can be entered into the model described in ACRP Report 25: Airport Passenger Terminal Planning and Design, Volumes 1 and 2, http://onlinepubs.trb.org/onlinepubs/acrp/acrp_rpt_025v1.pdf to generate requirements for ticketing, security screening, baggage make-up, and baggage claim facilities. Sample Only â Lead Times Vary Significantly by Airport Exhibit 7.2. Example of lead time distribution. Peak flows at departing passenger facilities occur in advance of the departures peak measured in a DDFS.
76 Guidebook for Preparing and Using Airport Design Day Flight Schedules 7.3 Landside Planning Once lead or lag time factors have been applied, DDFS passenger distributions or, more specifically, O&D passenger distributions can be converted into vehicle distributions using modal split and lead and lag time assumptions. The vehicle distributions are used as inputs to landside simulation models or simpler landside spreadsheet models. ACRP Report 40: Airport Curbside and Terminal Area Roadway Operations http://onlinepubs.trb.org/onlinepubs/acrp/acrp_rpt_040.pdf provides detailed guidance on ways to apply DDFS outputs to resolve landside planning issues. 7.4 Environmental Planning As noted in Chapter 3, the FAA requires the use of the AEDT model to calculate aircraft and airspace noise impacts, as well as airfield and landside air quality impacts. Two major adjust- ments are required before DDFS outputs can be applied to noise analysis. First, as the DDFS design day is typically a busy day, it must be scaled down to represent an average annual day. Next, the times in a DDFS reflect gate times rather than runway take-off and touchdown times, which are more appropriate for noise analysis. The difference can be significant at large, con- gested airports with extensive taxiing times and delays. Therefore, if a DDFS is used for noise analysis, it should be used in conjunction with an airfield simulation model to ensure that the output incorporates the effects of taxiing time and delay. Air quality dispersion analysis also requires that a DDFS be used in conjunction with an airfield simulation model. Before a DDFS can be used to estimate noise impacts, the O&D passenger output must be converted to vehicle movements. Once vehicle movements are estimated, TNMs can be used to estimate noise impacts from vehicles. Again, please note that the DDFS output needs to be con- verted to an average annual day format. DDFS output can be used to estimate ground vehicle emissions, but the output needs to be processed through models such as MOVES2014. Additional guidance on the application of DDFS output to airport environmental analysis is provided in the FAAâs AEDT Version 2b User Guide (FAA 2015). 7.5 Airport/Airline Operations and Management Near-term or real-time DDFSs are used to assist in airline and airport operations and manage- ment related to gate management and noise monitoring. Depending on its intended use, DDFS output can be entered directly into gate optimization or other facility management models, or processed through intermediate models for use in noise monitoring and other activities. 7.6 Staffing Depending on whether staffing requirements are related to airfield or terminal building oper- ations, intermediate aircraft or passenger distributions developed from DDFSs can be used to generate staffing requirements. As is the case with airport or airline management and operations, staffing requirements are based on near-term or real-time DDFSs.
