EXPLORING A TIME-BASED MANAGEMENT FLEET PRIORITIZATION SERVICE

Amanda Matthews, Dr. Marcus E. B. Smith, Amanda M. Staley, and Sally StalnakerThe MITRE Corporation, McLean, Virginia

Abstract When National Airspace System (NAS) flight

demand (e.g., Flight Operator operations) exceeds capacity (e.g., airport-, weather-, airspace-related) at a NAS resource the result is delay. To ensure an efficient NAS, the Federal Aviation Administration (FAA) uses various Time-Based Management (TBM) capabilities to balance capacity and demand across NAS resources. These capabilities assign the resulting delay across the resource flight demand. For example, the FAA uses the Time-Based Flow Management (TBFM) system to manage the balance between demand and capacity at arrival airports and departure fixes/flows by assigning delays across airborne and ground-based flights. TBFM is not creating delay, rather assigning delay that exists within the NAS to balance traffic demand with available capacity. TBFM uses controlled departure times to assign this delay on an as-requested approach. There is a desire among flight operators to provide priority inputs that can be accounted for by TBFM in order to minimize delay assigned to those flights that are most important to them in meeting their business objectives. Fleet Prioritization concepts, which intend to address this desire to better accommodate flight operator preferences as part of TBM, is considered consistent with achieving increased Operational Flexibility, one of four stated objectives in the FAA’s Vision for Trajectory-Based Operations (TBO).

The MITRE Corporation in collaboration with the Federal Aviation Administration (FAA) is analyzing and exploring how a TBM Fleet Prioritization Service can be incorporated as part of future TBFM system capabilities. The Flight Operators’ needs for Fleet Prioritization and a concept for this was investigated, including concept elements that would be needed. Process-, procedural-, and automation-based methods were identified to achieve Fleet Prioritization goals. The scope of

shortfalls related to TBFM and broader TBM operations were explored and data analysis performed to determine to what extent operational and/or business considerations necessitate the prioritization of flights to reallocate assigned delay in TBM operations. TBM assigned departure delays can vary widely for a flight; however, current operational TBM practices provide only a limited planning horizon for potential prioritization activities. The prioritization of flights requires sufficient planning time to ensure that the flight operators can meet business needs. Further data analysis highlighted that the advantages of applying increased scheduling lead-time as a means to minimize delay are location-dependent and not consistent NAS-wide. Therefore, any envisioned Fleet Prioritization service will require location-specific considerations. This paper will describe how the FAA should make both near-term and longer-term improvements to exchange data with flight operators, mature the concept, and utilize existing capabilities to improve flight operator preference accommodation.

Introduction The Federal Aviation Administration (FAA) is

transitioning the National Airspace System (NAS) to Trajectory Based Operations (TBO) [1] which relies upon information sharing, Time-Based Management (TBM), and Performance Based Navigation (PBN), among other enablers, to define and maintain a four-dimensional trajectory for each flight. TBM is the use of time as a common planning variable to define a sequence and appropriate flight crossing time at constrained points that efficiently balances traffic demand with available airspace and airport capacity. For TBO, TBM is enabled by three National Airspace System (NAS) systems—the Time-Based Flow Management (TBFM) system, the Traffic Flow Management System (TFMS), and the forthcoming Terminal Flight Data Management (TFDM) system, see Figure 1.

Figure 1. TBO Evolution [FAA]

The FAA has been exploring a TBM Fleet Prioritization Service as part of a future TBFM programmatic investment. Investment in Fleet Prioritization concepts, which intend to address the accommodation of flight operator preferences within TBM, is considered consistent with achieving increased Operational Flexibility, one of four stated objectives in the FAA’s Vision for TBO.

As such, the FAA requested MITRE investigate the flight operator need and NAS preparedness to support Fleet Prioritization concepts, as well as recommend process, procedural, and automation-based methods to achieve Fleet Prioritization goals.

Background: What is Fleet Prioritization? Today, the TBFM system balances traffic

demand with available capacity on a ‘first-come, first served’ operating basis. When traffic demand exceeds capacity, a delay (airborne or ground) is required and is assigned to a given flight without regard to any contextual information about that flight. The flight operators requested that the FAA enable the ability to provide preferences (i.e., flight-specific priorities1), which would take into account their business objectives, for the allocation of delay to their flights.

Fleet Prioritization concepts have captured this desire in the application of TBM in a real-time

manner, while flights are either pre-departure or airborne. To do this, the flight operators need to have the ability to view all their operations (e.g., for a day, several days) and decide the relative importance of one flight over another flight, looking at the entire fleet and making decisions about flights, as shown in Figure 2.

Fleet Prioritization is envisioned to provide flight operators the ability to submit flight preferences to be used in TBM assignments and the ability for flight operators to substitute flights in TBM operations.

FAA and flight operator functionality and mechanisms for exchange of information is required. This includes flight operator designation of priority, exchange of and use of flight operator priority values for individual flights.

Fleet Prioritization would enhance automation to process flight operator-provided priority values and reassign delay from high-priority to low-priority flights without significantly impacting other flights in the schedule.

1 Flight-specific priority is the ability for the flight operators to indicate one flight should be scheduled and/or rerouted before another flight(s). This has been described as a flight only priority and mostly appears to be tactical in nature, i.e., not decided hours in advance.

Figure 2. Flight Priority Concept [MITRE]

Background: HistoryThe FAA has identified strategic goals regarding

the incorporation of flight or fleet priority. These goals are captured in the Next Generation Air Transportation System (NextGen) Implementation Plan (NSIP) Operational Increments (OIs) [2], specifically TBFM Portfolio OI 104120-28 FOC Preferences Incorporated into Metering. Developed in 2010 by Mosaic ATM and Metron Aviation, the Airborne Execution of Flow Strategies (AEFS) concept attempted to address OI 104120-28 and the flight operator-expressed desire to provide priority for TBFM scheduling and to substitute within TBFM. AEFS had two main capabilities: Automated Incorporation of Fleet Prioritization and Fleet Prioritization by Substitution in TBFM and TBFM Delay Estimator [3]. Future, FAA-planned improvements and additional concepts (including Flight and Flow Information for a Collaborative Environment (FF-ICE), Unified Flight Planning and Filing (UFPF), and Common Support Services – Flight Data (CSS-FD)), were not included as part of the AEFS concept. The last demonstration of AEFS was at the FAA’s Florida NextGen Test Bed facility in 2014.

As part of the work to assess the maturity and benefits for a potential TBFM programmatic investment, the FAA conducted a maturity analysis on Fleet Prioritization capabilities that identified concept questions associated with the AEFS concept and additional research that needed attention prior to Fleet Prioritization being suitable for NAS operations. Given the current maturity state for enabling a Fleet Prioritization service, the FAA has not yet assigned Fleet Prioritization as a candidate capability as part of a TBFM programmatic investment.

ApproachTo explore if and how a TBM Fleet

Prioritization Service can be incorporated as part of future TBFM capabilities, MITRE undertook the following approach:

Evaluate the operational need for a TBM Fleet Prioritization service. The scope of the evaluation should include a survey of operational needs cited by the previous concept, AEFS, as well as any OIs that include aspects of this concept.

Identify and describe opportunities for a TBM Fleet Prioritization service. The identification should include the feasibility of each opportunity considered. The near-term, identified feasible opportunities should include key steps to achieve it and anticipated challenges and/or open questions that need to be addressed.

Identify and describe long-term considerations for achieving a TBM Fleet Prioritization service.

The outcome of each of these steps is described in detail in the sections that follow.

Evaluation of NeedTo evaluate the operational need for a TBM

Fleet Prioritization service, the approach focused on the Who, What, When, Where, and How, to explore the scope and limitations of the possible Fleet Prioritization problem space. The outcome of the evaluation, as described below, defines the service user and their operational intent, focusing on current TBM operations.

Operational NeedThe envisioned Fleet Prioritization service is

intended for use by the flight operators to have input on the redistribution of TBFM-assigned flight delays to better support business needs, such as preserving arrival on-time performance of high priority flights. The FAA can benefit from use of aspects of Fleet Prioritization by changing allocations of assigned delay to meet operational needs at the ARTCC, TRACON and ATCT. TFMS allows flight operators a prioritization mechanism through substitution for use in select Traffic Management Initiatives (TMIs). TBFM has no equivalent capability.

The flight operators focus upon the on-time performance (as defined by at-gate arrival within 14

minutes of scheduled time [A+14]) for certain high-priority flights that TBFM assigns a large departure delay, to ensure integrity of their published schedules.

The team first had to explore the link between the assigned TBFM delay and flight operator’s focus on on-time performance. The team identified the top 10 departure airports in the NAS by number of flights with TBFM-assigned departure delay of 15 minutes or greater. Flights with TBFM-assigned departure delays of 15 minutes or more are considered as receiving large TBFM-assigned departure delays. The team generated the results with a MITRE dataset that fused both TBFM internal and System Wide Information Management (SWIM) data, over Fiscal Year (FY) 2018. Figure 3 identifies that Ronald Reagan Washington National Airport (DCA) was the most impacted TBFM-assigned departure delay2 airport by number of flights in FY2018. DCA experienced over 3200 operations in FY2018 with TBFM-assigned departure delays 15 minutes or greater.

Figure 3. Top 10 NAS Airports by Count of Flights with TBFM-Assigned Departure Delay 15

Minutes or Greater (FY2018) [MITRE]

A more detailed understanding of these impacted flights from DCA can be achieved by focusing on the Origin-Destination (O-D) pair operations. Table 1 identifies the top 5 destination airports for flights from DCA with large TBFM-assigned departure delays. New York LaGuardia Airport (LGA) is the most impacted destination with over 1600 flights in FY2018.

Table 1. Most Impacted Destination Airports from DCA for Flights with TBFM-Assigned Departure Delay 15 Minutes or Greater (FY2018) [MITRE]

Arrival Airport TBFM-assigned Departure Delay15 30 45 60 75+

LGA 1029 408 132 46 25EWR 308 123 36 5 -ATL 166 36 2 1 -CLT 175 5 - 1 -ORD 46 2 - - -

The impact of excessive TBFM-assigned departure delays becomes apparent when considering these flights between DCA and LGA. Not surprisingly, the comparison of assigned delay to arrival on-time performance in Figure 4 shows that average TBFM-assigned departure delays over 15 minutes lead to poor A+14 performance. Compounded by the fact that there are limited airborne opportunities to offset that assigned departure delay on such a short route.

2 Definition of what constitutes “Large” TBFM-assigned departure delays was based on input from FAA Subject Matter Experts (SMEs).

Figure 4. Average TBFM-Assigned Departure Delay by on-Time Performance for KDCA to

KLGA (FY2018) [MITRE]

This example helps emphasize how operational and/or business considerations would benefit from a means to prioritize flights by reallocating delay to flights with less significant operating impact to ensure overall operator business goals are achieved.

Operational ObjectivesThe ability for flight operators to plan is

paramount in providing a viable fleet prioritization service. The ability to plan in TBFM departure scheduling operations equates to a flight’s “scheduling lead-time”. This lead-time is characterized as the time between the TBFM scheduled departure time, and the earliest possible time that the flight can be at the end of the runway. Currently, the median scheduling lead-time in the TBFM system across the NAS is approximately 10 minutes, reflective of TBFM’s tactical nature. Figure5 highlights this reality at DCA. The graph depicts the relationship between lead-time and assigned delay for flights with a single TBFM scheduling event. These single scheduling event flights (~5100 flights) where chosen to focus on “nominal” TBFM operations, so a true picture of the lead-time behavior at the facility could be understood. The solid colored lines in Figure 5 depict the percentile of flights with similar assigned delay, the broken red line depicts the average assigned delay behavior for flights from DCA. As the percentage of flights included increases, the scheduling lead-time coalesces towards the 10-minute mark.

Figure 5. TBFM Scheduling Lead-Time (mins) versus Assigned Departure Delay (mins) for DCA

(FY2018)

The next step for the team was to understand the instantiation of this lead-time to TBFM-assigned departure delay behavior for an individual flight. The team identified the top 6 most impacted flights from DCA to LGA by number of flights with a TBFM-assigned departure delay of 15 minutes or greater. All these flights happened to be from the same regional carrier as shown in Figure 6. The regional carrier flight 1111 (REG1111) was the most impacted, with at least 10 more flights over and above the nearest other flight, REG1222.

Figure 6. The Most Impacted Flights from DCA to LGA with TBFM-Assigned Departure Delays 15

Minutes or Over (FY2018) [MITRE]

Decomposing the instantiation of the TBFM-assigned departure delays for REG1111 over FY2018 highlights the variability that comes with TBFM operations, seasonal demand variation, and other factors (including weather), highlights the need for flight operator planning. Figure 7, shows the variability in TBFM-assigned departure delay from 0

to 60 minutes for REG1111. Similar variability was seen for the other flights in Figure 6. The variability shown for even this single flight underscores why flight operators desire the ability to provide flight priority inputs that can be accounted for by the TBFM system’s assignment of delay, particularly the operations in the red box, with assigned delays over 30 minutes. The current TBFM delay assignment model does not allow a systematic and automated way of accomplishing that.

Figure 7. Variability of TBFM Assigned Departure Delay for REG1111 Against TBFM

Scheduling Lead-Time (FY2018)

Figure 8. Summary of TBFM Scheduling Lead-Time vs TBFM-Assigned Departure Delay

Analysis Comparison for LGA and MSP for a Single Scheduling Event (04/2018 – 09/2018)

[MITRE]

Summary of NeedIn terms of the operational need, large TBFM-

assigned departure delays are detrimental to on-time performance, impacting the flight operators. Further compounding the issue, delay magnitude is variable, making prediction of delay difficult for any one flight.

In terms of operational objectives, the current median lead-time in TBFM departure scheduling is close to 10 minutes NAS-wide [14], in line with TBFM’s tactical nature. The advantages of applying increased scheduling lead-time as a means to minimize delay may be location-dependent and not necessarily consistent NAS-wide. Therefore, additional location considerations may be required in the use of the service to determine appropriate and optimal early scheduling lead-times. Differences in operations could require special planning considerations depending on location.

In summary, operational and/or business considerations require a means to prioritize aircraft to reallocate assigned delay to ensure goals are achieved in TBM operations. The current capabilities and procedures in place today make implementation in the near-term challenging.

Solution SpaceMITRE explored near-term and far-term

solutions as a result of understanding the current flight operator prioritization limitations and associated problem space. Both near-term and far-term solutions considered capabilities beyond TBFM system-based capabilities.

Near-Term OpportunitiesIn the near-term, existing flight operator-

provided inputs have an opportunity to be leveraged as TBFM prioritization methods with minimal changes to operations and automation systems. MITRE determined the methods in Table 2 have potential use for enabling prioritization in some fashion in the near-term (e.g., substituting arrival slots during Ground Delay Programs [GDPs] in TFMS to prioritize one flight over another). These methods all have pros and cons, as documented in Table 2, and should be reviewed and discussed between the FAA and flight operators for feasibility and efficacy.

Table 2. Near-term Prioritization Enabling Methods and Mechanisms [MITRE]

Prioritization Method Concept Statement (Prioritization Use)

Flig

ht O

pera

tor

Prov

ided

Tim

es

Earliest Off Block Time

(EOBT) [4]

• EOBTs are used to provide data on readiness and to be used by TFDM to schedule Call for Release (CFR) flights

• EOBTs prioritize flights for arrival or overhead stream slots• Pros

– Flight operator updated EOBT can indicate priority over other flights at the same airport – Propagated through Traffic Flow Management Systems via TFDM ETD update

• Cons– No consistent use of operator provided departure estimates across all systems

Earliest Runway Time of Departure

(ERTD) [5]

• ERTDs are provided by airlines prior to GDP, Airspace Flow Program (AFP), CTOP, Ground Stop (GS)-GDP to prioritize flights

• Used by TFMS when assigning Expected Departure Clearance Times (EDCTs) • Pros

– Flight operator updated ERTD can indicate priority over other flights with EDCT for the same constrained resource

– Already used by TFMS to update departure time which is used to update demand prediction • Cons

– No consistent use of operator provided departure estimates across all systems

Airline Gate Time of Departure

(LGTD) [5]

• Flight operator provided and used to improve demand predictions when aircraft gets impacted by TMI • A time submitted and updated by CDM members via TFMS • Pros

– Flight operator updated LGTD can indicate priority over other flights at the same airport (LRTD time would be better)

– Indirect departure preference – 86.9% of flights from DCA submitted an LGTD in FY2018.– Already used by TFMS to update departure time which is used to update demand prediction 

• Cons– No consistent use of operator provided departure estimates across all systems

Airline Runway Time of Departure (LRTD) [5]

• Flight operator provided estimated wheels up time• Used by TFMS in ETD hierarchy• Pros

– Flight operator updated LRTD can indicate priority over other flights at the same airport – Indirect departure preference – 86.4% of flights from DCA submitted an LRTD in FY2018.– Already used by TFMS to update departure time which is used to update demand prediction 

• Cons– No consistent use of operator provided departure estimates across all systems

P-Time (Departure Time)

• Departure time provided in flight plan • Standard used for departure time • Pros

– Flight operator updated P-Time can indicate priority over other flights at the same airport, by putting them into a time series.

– Already used by TFMS to update departure time which is used to update demand prediction • Cons

– About 90% of flights provide only one P-Time and don’t update the time – No consistent use of operator provided departure estimates across all systems

Prioritization Method Concept Statement (Prioritization Use)Fl

ight

Ope

rato

r Pr

ovid

ed

Info

rmat

ion

Trajectory Options Set (TOS) [6]

• Within a CTOP, flight operators can provide TOS indicating ground delays, routes, and their associated preferences

• Pros– Direct method of prioritization

• Cons– Requires planning and software support on flight operator side to generate TOS– Requires a planning and software changes on the FAA side to accommodate arrival slot

substitution – Not currently used

Flight Plan Amendment

• Flight operators provide an update to the route based on FAA-provided offload routes• This allows the flight operators to choose a different route in order to depart sooner.• Pros

– Direct method of prioritization • Cons

– Unclear on how often flight plans are updated today and if there are any restrictions– Manually intensive for the FAA to identify priority and to act on it – FAA will need to be more proactive to provide offload routes

Oth

er P

re-D

epar

ture

Met

hods

TFDM Substitution [7]

• Substitution in TFDM is only used during SMP program. • Flights subject to other TMIs are not allowed to substitute in a SMP. • SMP substitutions means flights are switching Target Movement Area Entry Times (TMATs).• Pros

– Direct method of prioritization • Cons

– Very limited prioritization because TFDM Substitution is only allowed in a SMP

TBFM Ground Over Air Priority [8]

• TBFM Ground Over Air Priority forces a flight into a partial departure slot or makes a slot for them • Can be used in two ways: by individual flight (manual) or global (auto set up) • Capability exists but infrequently used • Pros

– FAA can prioritize flights to get them off the ground– Flight operators can call ARTCC/TRACON TM to ask if the flight can get priority

• Cons– Airborne delay increases– Limited application due to manual call and change

Manual TMC swapping of departure flights in TBFM

• TBFM Swapping of departure flights, allows a TMC to swap two departure flights and their Controlled Time of Departure (CTDs) over the same constraint

• Capability exists but limited to time exchanges at the same airport • Pros

– Allows a TMC to react to operationally • Cons

– Limited to swapping 2 flights over a single constraint from a single airport

TFM

S-R

elat

ed M

etho

ds

TFMS Substitution [9]

• Only used during GDP/AFP/CTOPs. Substituting arrival slots at the Flow Constrained Area (FCA) or airport, not the Expect Departure Clearance Time (EDCT).

• No restrictions if flight subject to other TMIs (e.g., TBFM metering or SMP)• Tactical Customer Advocate (TCA)/EDCT change request: The command center has a TCA desk

which addresses airline concerns regarding GDPs, AFP, and GS. • Pros

– Direct method of prioritization– Flight operators actively use this capability and find it useful

• Cons– Using this method could impact flights subject to CFR and/or SMP. This could require FAA

manual processes to reconcile. – Flight operator substitution could be manually intensive.

Pre-Departure Rerouting

• Used by FAA to tactically reroute pre-departure flights. • Verbal communication between flight operators and FAA for flight operator-initiated flight priority • Not currently in use due to software issue

Prioritization Method Concept Statement (Prioritization Use)

(PDRR) • Pros– Direct method of prioritization

• Cons– FAA TM workload concern– There is no way to ensure that all flight operators have a fair and equitable chance of reroute.

En

Rou

te

Met

hod

Airborne Re- Routing

(ABRR)

• Used by FAA to tactically reroute airborne en route flights. • Verbal communication between flight operators and FAA for flight operator-initiated flight priority • Not currently in use due to software issue• Pros

– Direct method of prioritization– Flight operators can call to request reroute in order to avoid constraints

• Cons– FAA controller workload issue– There is no way to ensure that all flight operators have a fair and equitable chance of reroute.

For near-term solutions considered, an issue arises that multiple automation systems accept some form of flight operator prioritization inputs but for different, inconsistent purposes (e.g., TFDM substitutions for Surface Metering Procedures [SMPs], TFMS substitutions for GDPs/Collaborative Trajectory Options Program [CTOPs]). This results in a piecemeal way of accommodating flight operator preferences. This adds complexity to the operation for flight operators in that they must remain cognizant of all prioritization requests made and determine how each request affects their ability to perform other operations (e.g., substitutions in multiple systems). For the FAA, automation complexity will need to increase to deconflict prioritization requests, ensuring that one system does

not detrimentally impact another (e.g., TFMS substitution impact on TBFM scheduling).

Long-Term ConsiderationsIn the far-term, there are many concepts that aim

to facilitate more collaboration between the FAA and flight operators by providing the flight operators with an enhanced ability to prioritize their flights while the FAA can maintain efficient NAS operations. These concepts range from simply tracking all constraints associated with a flight to introducing data standardization. Some of these concepts are no longer actively being pursued, but they have some relevancy to flight operator preferences for TBM operations and should be leveraged. Descriptions of these concepts are provided in Table 3.

Table 3. Long-Term Considerations for Prioritization Enabling Mechanisms [MITRE]

Concept Name Concept Description

Common Support Services-Flight Data (CSS-FD) [10]

A new FAA program to provide standards-based flight planning environment, supporting FF-ICE/1 provisions and FIXM standard. CSS-FD encompasses portions of several other concepts including Unified Flight Planning and Filing (UFPF), Fight Object Exchange Service (FOXS), SWIM Flight Data Publication Service (SFDPS), and NAS Common Reference (NCR). CSS-FD includes predeparture trajectory negotiation, contingency and flight plan handling, and flight data standards.

Flight and Flow Information for a Collaborative Environment (FF-ICE) [11]

FF-ICE defines information requirements for flight planning, flow management and trajectory management and aims to be a cornerstone of the performance-based air navigation system.

FF-ICE/1 is supported by CSS-FD. FF-ICE/2 supports TBO through exchange and distribution of information including execution phase for multi-center operations using flight object implementation and interoperability standards. FF-ICE/3 ensure data for all relevant flights is systematically shared between air and ground systems using SWIM in support of collaborative Air Traffic Management (ATM) and TBO.

Flight Object [12] A collection of common information elements that describe an individual flight, its capabilities, preferences and constraints available electronically for use by system stakeholders and ATM service providers facilitates the sharing of common flight information elements among new and existing capabilities as the system evolves.

The flight object description does not include environment or weather information since these are system-wide elements that affect multiple flights.

Constraint Evaluation Feedback (101102-21)

This increment provides opportunities to enhance flight efficiency and route predictability by providing flight plan evaluation and feedback that permit the users see how they can modify their plans to resolve flow problems. Automation provides flight plan format and logic checking, route conversion, route evaluation and feedback for trajectory alternatives submitted by aircraft operators. Collaboration partners are also provided information on constraints by airspace volume for strategic flow plans that are in effect and flow contingency plans under consideration.

Concept Name Concept Description

Additional Flight Plan Options and Preferences (101102-22)

This increment enables users to provide flight plan options and preferences if constraints materialize or dissipate. Users may file alternative trajectories, which in the case of Unmanned Aircraft Systems could include the route the aircraft would be pre-programmed to fly in the event of a loss of communication between the pilot-in-command and the aircraft, which represent the desired route if constraints materialize. Oceanic flights will also be able to evaluate whether airspace constraints will impact their route of flight. The options and preferences are considered in constraint evaluation facilitated by a commonly sourced/shared aviation information environment for collaborative decision making.

Aircraft Access to Advanced Flight Planning Information (101103-32)

Users, including all NAS participants, will have improved airborne access to more advanced NAS planning information that is consistent with international flight planning standards and include all relevant flight constraint information. This improvement will further enhance the ability of users to collaborate with the FAA from the aircraft, resulting in improved flow management and efficient use of resources. As part of the total system-wide information management environment, participants will have access to more detailed consistent and continuously updated information regarding expected constraints in the system. Timely access to such information will enable both operators and service providers to take action (e.g., request a re-route or be offered access) as new information becomes available.

Access to Airborne Reroute Evaluation, Feedback, and Synchronization (101103-33)

This increment establishes the airborne component of trajectory evaluation, feedback, and synchronization that provides airspace users the ability to update alternative trajectory options and preferences throughout the flight in response to changing conditions. It provides the ability for all parties (i.e., the flight deck, flight operations centers, and traffic managers) to evaluate constraint and trajectory information and ensures that all parties have the same information for airborne reroute decision making. User flexibility is also improved by allowing the use of flight planning functions while airborne. It enables users to assess and select alternative airborne reroute options in support of traffic management improvements which increase the user's ability to select the reroute that best meets their business objectives.

Command and Control Flight Information Service (101202-21)

This increment will improve overall flight information management for tactical operations across the domains and enable enhanced flight data management capabilities and ATC inter-operability between facilities. It provides the interface architecture to exchange safety critical flight information with internal ATM systems, enabling all command and control systems to have current synchronized real-time flight plan information. This increment implements the infrastructure and information management mechanisms for flight information sharing between command and control systems by establishing the services and mechanisms to manage the data between systems which includes the framework for managing authoritative source, authorization, operational eligibility, and subscription requirements.

Extended Flight Planning Horizon (101202-23)

This increment provides the infrastructure that enables the FAA and Airspace Users to extend the collaborative planning horizon to days or months in advance. The exchange of flight information will be based on the use of standardized flight information through established exchange standards. Users will be provided with a single interface they can use to transition their flight plan from a preliminary planning state to the services that manage active real time states of the flights all the way through to the flight's destination. This planning information will be retained and enable more detailed flight plan information (e.g., a fully converted route and trajectory) to be used by both internal and external users for strategic planning as well as during the active flight. This will improve the overall accuracy of demand estimates made throughout the system, determining whether capacity constraints exist, and enable electronic collaborative methods for alleviating demand versus capacity imbalances for active flights.

Concept Name Concept Description

Airborne Trajectory Negotiation (105207-28)

The ability of Flight Operations Centers (FOCs) and flight crews to provide preferences for airborne reroutes enables the users to choose the reroute that best meets their business objectives. This can be a two or three-party negotiation, as appropriate, involving the flight planner and/or the flight crew and traffic manager working the tactical flow contingency plans. For performing real-time trajectory negotiation for trial planning, coordinating, issuing, and accepting or rejecting trajectory changes (reroutes) in real-time FOC involvement in airborne reroutes will vary depending on the complexity of the constraint and temporal conditions. Automation tools will enable traffic managers and FOCs/Pilots to negotiate these trajectories. The accepted trajectory will be sent to the R-controller in the form of a proposed revised route clearance to send to the aircraft via data communications or can be sent as a reroute request directly from the aircraft.

Advanced Flight-Specific Trajectories (105208-25)

Traffic managers and controllers are provided with integrated automation tools to resolve constraints with advanced flight-specific trajectory changes that are generated by automation. These capabilities enhance capacity and flight efficiency. In addition, automation will automatically evaluate opportunities to improve trajectories and reduce delay when constraints diminish or evolve differently than predicted. Traffic managers will resolve constraint problems for both airborne and pre-departure flights from 20-90 minutes prior to flights encountering the constraint and send revised trajectories to the appropriate sector controller to deliver to the cockpit via data comm. Revised trajectories may be complex and developed based on a wide range of input factors, such as weather, sector capacity, special activity airspace (SAA), NAS equipment outages, operator preferences, and metering time assignment. The trajectory modifications will include reroutes, attitude changes, and ground delays.

ANSP Real-Time Status for SAAs (108212-11)

Airspace use is optimized and efficiently managed in real time, based on actual flight profiles and real-time operational use. Airspace reservations for military operations, unmanned aircraft, space flight and re-entry, restricted and warning areas, and military flight training and altitude reservation areas are managed on as scheduled. Enhanced automation-to-automation communications and collaboration enables decision-makers to dynamically manage airspace for special use, increasing real-time access and use of available airspace.

User Driven Prioritization Process (UDPP) [13]

User driven prioritization process (UDPP) is designed to allow airspace users to intervene more directly in the implementation of flow regulations, in particular in cases where an unplanned degradation of capacity significantly impacts the realization of their schedule. The module proposes a simple mechanism by which the affected airlines can collaboratively among themselves and with ATFM come to a solution which takes into account their commercial/operational priorities which are not known by ATM. Due to the potential complexity of several intricate prioritization and allocation processes, this module will implement UDPP only in specific situations, e.g. when the perturbation affects one airport.

5.8 SLOT-SWAPPING (UDPP) Status: SESAR concept ready for deployment From an Airspace Users’ point of view, not all flights are equal in terms of schedule priority. If two flights from the same airline crossing the same congested airspace or airport are both given time constraints, the Airspace User may swap these time constraints to reorder their flights aligned to the airline’s priorities.

Ultimately, a long-term TBM Flight Prioritization Service needs to be developed that accommodates all NAS systems and constraints (in lieu of a piecemeal fashion that has been previously pursued via a TBFM-only solution and currently available as part of a TFMS-only solution). While some concept elements exist in current automation systems (e.g., CTOP in TFMS), the goal is for these concept elements to broaden and integrate flight operator flight prioritization inputs among all TBM-

enabling NAS systems and constraints. Furthermore, the Flight Prioritization concept needs to leverage and appropriately consider future FAA-planned improvements (e.g., CSS-FD and User Driven Prioritization Process). Toward that, MITRE identified four concept elements, which are as follows:

FAA provides information on delays and constraints to the flight operators strategically and tactically.

– This is new to TBFM in a strategic sense but exists in some fashion in TFDM and TFMS.

Flight operators determine their “flight priorities.” Examples include:– What must arrive when,– What must depart when, and– Where and when can delays or longer flight

times be taken. Flight operators provide “flight priorities” to the

FAA.– This is new to TBFM but exists in some

fashion in TFDM and TFMS. FAA attempts to best accommodate the flight

operator-provided “priorities” by assigning delays and reroutes according to the priorities.– This is new in an integrated sense, where all

constraints are considered and the priorities are distributed and addressed in all constraints, not in disparate constraints and systems as is done today.

FAA automation is updated to keep track of real-time flight operator-provided priorities through the entire flight (departure to arrival) and any delays associated with the flight.– Some aspects of this are new to NAS

operations.

Recommendations MITRE recommends that Fleet Prioritization be

referred to as “TBM Flight Prioritization Service,” where the concept enables flight operator flight prioritization in real-time, provided in a continuous and cohesive manner, given NAS operations and constraints. This slight change provides name recognition and clarification as to the role NAS operations and automation can play, deconflicting from flight operator business objectives at large.

To realize the proposed TBM Flight Prioritization Service concept elements described above, MITRE recommends the following actions:

Additional TBM data, beyond what is available in existing SWIM feeds, needs to be made available to flight operators and in an earlier timeframe (as feasible). This will allow flight operators to have more insight into the impact of TBM operations to their flights, and to allow them enough time to respond and collaborate with the FAA accordingly.

Additional research and concept maturation for the proposed TBM Flight Prioritization Service is necessary to ensure the concept aligns with flight operator needs and FAA TBM goals.

Future vision and mission goals should be updated and consolidated to align with Flight Object / Collaborated Trajectories / FF-ICE concepts so that there are common, cohesive FAA and flight operator strategies for accomplishing the proposed TBM Flight Prioritization Service concept.

In the interim, MITRE recommends FAA-flight operator discussions specifically on the near-term methods (e.g., Estimated Off Block Time updates, TFMS substitutions, TBFM ground over air priority) and the efficacy of addressing some operator pain points today. These discussions should aim to reach agreement on specific procedures, processes, and outcomes to meet addressable high-priority operational needs.

ConclusionThe imbalance between NAS flight demand

(e.g., flight operator operations) and capacity (e.g., airport-, weather-, airspace-related) results in delay. To ensure an efficient NAS, the FAA uses various capabilities to balance capacity and demand across NAS resources. These capabilities are used to assign the resulting delay across the resource flight demand.

The FAA uses the TBFM system to tactically manage the balance between demand and capacity at arrival airports and departure fixes/flows. In TBFM, delays can be assigned across airborne and ground-based flights depending on the metering modes. TBFM is not creating delay, rather assigning delay that exists within the NAS. Delays are assigned on a first come first served basis, without pre-scheduling.

Flight operators identified a desire to provide flight priority inputs that can be considered by TBFM’s delay assignment in order to minimize delay for those flights that are important in meeting their business objectives.

Exploring the scope of shortfalls related to TBFM and broader TBM operations, data analysis has determined:

Operational and/or business considerations require a means to prioritize aircraft to reallocate

assigned delay to ensure goals are achieved in TBM operations.

The current operational TBM practices provide a limited planning horizon for prioritization activities.

MITRE identified concept elements for a far-term TBM flight prioritization service concept that would incorporate flight operator preferences into broader NAS operations. MITRE also identified near- and far-term solutions as a step forward in how flight operators can have their preferences incorporated into operations; however, further analysis needs to be performed to determine specifically how these solutions address the shortfalls identified and how they would work in an integrated fashion to support the far-term concept.

References[1] FAA, September 2017, “Vision for Trajectory Based Operations,” draft version 2.0 unpublished, Washington, DC.

[2] FAA, 2019, “NextGen Implementation Plan 2018-2019,” available: https://www.faa.gov/nextgen/media/NextGen_Implementation_Plan-2018-19.pdf, Washington, DC.

[3] Miller, M. E., et al., October 2014, “Airborne Execution of Flow Strategies Simulation,” 33rd

Digital Avionics Systems Conference (DASC), Colorado Springs, CO, pp. 1D1-1 – 1D1-6.

[4] FAA, November 2013, “TFDM Core for ATCTs Concept of Operations” ConOps-PMO-02-TFDM-13-001, Revision 2.1, Washington, DC.

[5] FAA, January 2017, “Java Messaging Service Description Document: Traffic Flow Management Data Service (TFMData)” CSC/TFMM-15/2057, Final 2.0.5.3, Washington, DC.

[6] CSRA, October 2013, “Traffic Flow Management System (TFMS) Collaborative Trajectory Options Program (CTOP) Interface Control Documents (ICD) for the Traffic Flow Management-Modernization (TFM-M) Program” CSRA/TFMM-13/1620, Version 3.3, available at http://cdm.fly.faa.gov, Rockville, MD.

[7] Cole, E. and M. Brown, September 2019, “Flight Operator Substitution in TFDM and TFDM Flight Collaboration Service (TFCS)” ATD-2 Technical

Exchange Meeting, available: https://aviationsystems.arc.nasa.gov/atd2-industry-workshop/presentations/7A_ATD2%20Industry%20Day%20-%2005Sep19%20-%20TFCS%20and%20Substitution.pdf, Dallas, TX.

[8] FAA, February 2015, “TBFM TMC Training, Lesson 6: TMC Arrival Metering Tasks,” Version 1.00, Washington, DC.

[9] CSRA, February 2016, “Flight Schedule Monitor User’s Guide” Version 13.0 Client, Revision 7, available: https://cdm.fly.faa.gov/wp-content/list_yo_files_user_folders/cdm_editor/cdm_prod_fsm/final_rel%2013_tfms_fsm_user%27s%20guide_12686.pdf, Egg Harbor Township, NJ.

[10] RTCA, December 2017, “Recommendations for Focus in the Common Support Services – Flight Data (CSS-FD) Program,” available: https://www.rtca.org/sites/default/files/css_fd_recommendations_fnl.pdf, Washington, DC.

[11] International Civil Aviation Organization Air Traffic Management Requirements and Performance Panel (ATMRPP), March 2017, "Flight and Flow - Information for a Collaborative Environment, Manual on FF-ICE Implementation Guidance,” ATMRPP-WG32-WP/736, ICAO Thirty Second Working Group Meeting, Montréal, Quebec, Canada.

[12] C. N. Bolzak, et al., February 2018, “Flight Information Management Concept Description,” MTR180020, McLean, VA.

[13] N. Pilon, S. Ruiz, A. Bujor, A. Cook, and L. Castelli, 2016, “Improved Flexibility and Equity for Airspace Users during Demand-Capacity Imbalance - An Introduction to The User-Driven Prioritisation Process”, Sixth SESAR Innovation Days, Delft, Netherlands.

[14] Anis, Z. “Departure Flow Competition from Less Equipped Airports,” Volpe National Transportation System Center, May 2019.

AcknowledgementsThe authors would like to acknowledge and

thank Mr. Guillermo Sotelo and Cynthia Morris of the FAA for their review, suggestions, and continued support throughout this effort. The authors would also like to thank Dr. Victor Klimenko and David

Rabinowitz for their contributions to the data analysis underlying this work.

DisclaimerThis work was produced for the U. S.

Government under Contract Number DTFAWA-10-C-00080 and is subject to Federal Aviation Administration Acquisition Management System Clause 3.5-13, Rights In Data-General, Alt. III and Alt. IV (Oct. 1996).

The contents of this material reflect the views of the authors the MITRE Corporation, and do not necessarily reflect the views of the Federal Aviation Administration (FAA) or the Department of Transportation (DOT). Neither the FAA nor the DOT makes any warranty or guarantee, or promise, expressed or implied, concerning the content or accuracy of the views expressed herein. Approved for Public Release. Distribution Unlimited. 20-0556.

Email AddressesAmanda Matthews: amatthews@mitre.org

Dr. Marcus E. B. Smith: mesmith@mitre.org

Amanda M. Staley: astaley@mitre.org

Sally Stalnaker: sfrench@mitre.org

2020 Integrated Communications Navigation and Surveillance (ICNS) Conference

April 21-23, 2020