------------------------------------ ----------------------------------
                                       

  Reeves, John J.: 15027               
  ------------------------------------ ----------------------------------

+-----------+----------------------+---+---+-----------+-----------+---------+---+
|           |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| MP        |                      |   |   |           |           |         |   |
| 9         |                      |   |   |           |           |         |   |
| 8W0000123 |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| MITRE     |                      |   |   |           |           |         |   |
| PRODUCT   |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| Mid-Term  |                      |   |   |           |           |         |   |
| FAA       |                      |   |   |           |           |         |   |
| -Airspace |                      |   |   |           |           |         |   |
| User      |                      |   |   |           |           |         |   |
| Coll      |                      |   |   |           |           |         |   |
| aborative |                      |   |   |           |           |         |   |
| Routing   |                      |   |   |           |           |         |   |
| Op        |                      |   |   |           |           |         |   |
| erational |                      |   |   |           |           |         |   |
| Concept   |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
|           |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
|           |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| Donald D. |                      |   |   |           |           |         |   |
| Olvey     |                      |   |   |           |           |         |   |
|           |                      |   |   |           |           |         |   |
| Lowell R. |                      |   |   |           |           |         |   |
| (Dusty)   |                      |   |   |           |           |         |   |
| Rhodes    |                      |   |   |           |           |         |   |
|           |                      |   |   |           |           |         |   |
| Laurel S. |                      |   |   |           |           |         |   |
| Carlson   |                      |   |   |           |           |         |   |
|           |                      |   |   |           |           |         |   |
| John J.   |                      |   |   |           |           |         |   |
| Reeves    |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
|           |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
|           |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| Sponsor:  | FAA                  |   | C |           | DTAF01-9  |         |   |
|           |                      |   | o |           | 3-C-00001 |         |   |
|           |                      |   | n |           |           |         |   |
|           |                      |   | t |           |           |         |   |
|           |                      |   | r |           |           |         |   |
|           |                      |   | a |           |           |         |   |
|           |                      |   | c |           |           |         |   |
|           |                      |   | t |           |           |         |   |
|           |                      |   | N |           |           |         |   |
|           |                      |   | o |           |           |         |   |
|           |                      |   | . |           |           |         |   |
|           |                      |   | : |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| Dept.     | F043                 |   | P |           | 0         |         |   |
| No.:      |                      |   | r |           | 298013FD4 |         |   |
|           |                      |   | o |           |           |         |   |
|           |                      |   | j |           |           |         |   |
|           |                      |   | e |           |           |         |   |
|           |                      |   | c |           |           |         |   |
|           |                      |   | t |           |           |         |   |
|           |                      |   | N |           |           |         |   |
|           |                      |   | o |           |           |         |   |
|           |                      |   | . |           |           |         |   |
|           |                      |   | : |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
|           |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
|           |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
|           |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
|           |                      |   |   | This      |           |         |   |
|           |                      |   |   | document  |           |         |   |
|           |                      |   |   | was       |           |         |   |
|           |                      |   |   | prepared  |           |         |   |
|           |                      |   |   | for       |           |         |   |
|           |                      |   |   | a         |           |         |   |
|           |                      |   |   | uthorized |           |         |   |
|           |                      |   |   | dis       |           |         |   |
|           |                      |   |   | tribution |           |         |   |
|           |                      |   |   | only. It  |           |         |   |
|           |                      |   |   | has not   |           |         |   |
|           |                      |   |   | been      |           |         |   |
|           |                      |   |   | approved  |           |         |   |
|           |                      |   |   | for       |           |         |   |
|           |                      |   |   | public    |           |         |   |
|           |                      |   |   | release.  |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| © 1998    |                      |   |   |           |           |         |   |
| The MITRE |                      |   |   |           |           |         |   |
| Co        |                      |   |   |           |           |         |   |
| rporation |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| MITRE     |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| Center    |                      |   |   |           |           |         |   |
| for       |                      |   |   |           |           |         |   |
| Advanced  |                      |   |   |           |           |         |   |
| Aviation  |                      |   |   |           |           |         |   |
| System    |                      |   |   |           |           |         |   |
| De        |                      |   |   |           |           |         |   |
| velopment |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+
| McLean,   |                      |   |   |           |           |         |   |
| Virginia  |                      |   |   |           |           |         |   |
+-----------+----------------------+---+---+-----------+-----------+---------+---+

# Foreword {#foreword .Front-Matter-Header}

This paper is a working draft of an operational concept for Federal
Aviation Administration (FAA)-Airspace User Collaborative Routing for
the mid-term (about 2005). It has been developed to assist the
Collaborative Decision Making (CDM) working group in defining and
evaluating its vision for collaborative routing. It is acknowledged that
some of the ideas expressed may not be operationally realistic for Air
Traffic Management (ATM) or users in the mid-term. These thoughts have
been included to stimulate discussion and perhaps eliminate notions that
have been in circulation but are ultimately not warranted from a cost,
benefit or feasibility standpoint.

The Center for Advanced Aviation System Development (CAASD) will solicit
feedback on the concept from the CDM working group members through a
facilitated discussion. The group's participation is important for
shaping a concept that is workable and responsive to both users' and
ATM's needs. Based on the feedback received, CAASD will refine the
concept, update the document, and publish it for distribution.

**Your Input and Opinions**

The final few pages of this document consist of questions related to
sections of the scenario presented in Section 4. After reading the
scenario, please take the time to think about these issues.

# Table of Contents {#table-of-contents .Front-Matter-Header}

Section Page

1\.

Assumed Capabilities for the Mid-Term

1.1 FAA Traffic Flow Management

1.2 OCC/Flight Planning Capabilities

2\. Roles and Responsibilities

2.1 FAA Traffic Management

2.2 Operational Control Centers (OCCs)

3\. Potential Benefits

4\. Scenario: Resolving Traffic Congestion through FAA---User
Collaborative Routing

4.1 Problem Identification

4.2 FAA-FAA Collaboration Initiated

4.3 FAA-User Collaboration Initiated

4.4 Flow Strategy Implementation

Section 1Number range Level1Number range Level2Number range Level3

# Number range Level3Number range Level2Assumed Capabilities for the Mid-Term

The assumed collaborative routing capabilities for the mid-term consist
of a mix of existing and proposed tools and capabilities. Listed
capabilities that do not yet exist are either in the planning stages, or
they are already included in the research and development pipeline.

## 1.1 Number range Level3Number range Level2FAA Traffic Flow Management

-   Tools to forecast congestion on a sector-by-sector basis up to two
    hours into the future.

-   Tools to select and evaluate flow strategies to alleviate predicted
    traffic congestion, including:

-   -- Number range Level3Dynamic resectorization

-   -- Reroutes (lateral and altitude)

-   -- Airborne holding

-   -- Miles in Trail

-   -- Combinations of the above

-   Tools to define airspace where traffic flow needs to be managed due
    to congestion, weather, etc. This airspace is called a Flow
    Constrained Area (FCA).

-   Tools to identify flights to be affected by the creation of an FCA.

-   Infrastructure to issue traffic flow management (TFM) advisory
    messages and collaboration invitations to all airspace users and to
    receive user preferences.

-   Tools to determine the number of flights that will need to receive a
    traffic management action, e.g., reroute or hold to resolve the flow
    problem (e.g., congestion).

-   Tools to allocate flow management actions to individual users.

-   Tools to develop/refine specific reroutes and hold assignments
    according to each user's allocation, taking Operational Control
    Center (OCC) preferences into account, if provided.

-   Tools to evaluate the impact of the aggregated specific reroutes and
    holds on the traffic congestion.

-   Infrastructure to allow transmission of flight plan amendments to
    the appropriate sectors or other service provider for clearance
    changes.

-   Conflict probe at the sector to ensure Traffic Management Unit (TMU)
    reroutes are conflict-free.

-   Infrastructure to permit FAA-FAA and FAA-airspace user visual
    collaboration and application sharing. This would permit the sharing
    of the same situation and decision support data among FAA and
    airspace users.

-   Visual collaboration capabilities to support the exchange of
    real-time information regarding airspace and flow restrictions with
    flight planners.

## 1.2 Number range Level3Number range Level2Number range Level3OCC/Flight Planning Capabilities

-   An interactive flight planning capability to allow the filing of
    airport-to-airport flight plans using user-preferred routes and
    altitudes on both domestic and international flights.

-   A flight planning (i.e., flight plan feedback) capability to
    identify National Airspace System (NAS) constraints such as
    hazardous weather, Special Use Airspace (SUA), flow restrictions and
    infrastructure outages that will affect a proposed route of flight.

```{=html}
<!-- -->
```
-   NAS constraint information is available to the dispatcher while the
    flight is being planned.

-   Flight plans are checked automatically to ensure that NAS
    constraints are not violated.

```{=html}
<!-- -->
```
-   Visual collaboration capabilities to support the exchange of
    real-time information regarding airspace, flow restrictions, and
    demand with FAA service providers.

-   The capability to load flight plan routes directly into the flight
    management systems of aircraft equipped with data link (a preferred
    option).

Section 2Number range Level1Number range Level2Number range Level3

# Roles and Responsibilities

National and local traffic managers will identify flow problems related
to traffic congestion, sector manageability, and workload issues. In the
case of developing weather situations, both traffic management and
airspace users will be involved in problem definition.

During situations when collaboration is possible, flow strategy
selection (i.e., the determination of whether to use holds, reroutes or
something else?) will be conducted through joint discussions among users
and the involved FAA facilities. The FAA will take user opinions into
account when formulating the strategy that will be used for the problem.

The FAA will define how much of a constraint will be imposed. (For
example, will we need to reduce the traffic in these sectors by 30% for
the next hour.) In addition, the allocation of the constraint across
users will also be handled by the FAA to ensure fairness.

Airspace users involved in a collaboration session will define
preferences for the aircraft in their fleet that are affected by a
proposed traffic management action. The FAA will factor these
preferences into the flow management action where feasible.

The FAA will implement the flow management actions at the single
aircraft level and will advise users of these actions through electronic
means, if possible.

At a more detailed level, the following roles and responsibilities are
assumed for the mid-term.

## 2.1 Number range Level3Number range Level2Number range Level3FAA Traffic Management

-   Traffic managers will review predicted traffic counts and complexity
    indices to identify potential traffic congestion situations
    (national and local TFM).

-   Principal FAA interface with the airlines for information
    dissemination and collaborative decision making (national TFM).

```{=html}
<!-- -->
```
-   Keeps airlines apprised of developing flow problem situations.

-   Facilitates FAA-user and FAA-FAA collaboration sessions.

-   Issues FAA requirements for collaboration (advisories, response
    time, strategy selected).

-   Receives users' preferences during collaboration (also local).

```{=html}
<!-- -->
```
-   Flow strategy development and evaluation (local and national TFM)

-   Flow strategy implementation at the single aircraft level
    (controller)

## 2.2 Operational Control Centers (Number range Level3Number range Level2OCCs)

-   Operational control and flight planning

```{=html}
<!-- -->
```
-   Determine potential consequences of reroute strategies proposed by
    FAA.

-   Number range Level3Evaluate available options in order to assure the
    safest and most efficient operation possible. (proactive)

-   Develop a plan to offload predicted congestion before the FAA takes
    action. Activate the plan if beneficial. (proactive)

-   Evaluate potential effects on fleet/crew resources and schedule if
    the FAA takes action to alleviate a flow problem. (reactive)

-   Define preferences and establishes priorities for its flights and
    communicates them to TFM. (proactive)

```{=html}
<!-- -->
```
-   Crew notification

```{=html}
<!-- -->
```
-   For flights that have not departed, the OCC will update the flight
    plan to reflect the reroutes and advise the flight crew of flight
    time and fuel burn for the new route as well as the user preferred
    route. This information will be included in the flight release and
    will provide the crew the necessary information to fly either route.

-   Using data link or company radio, the OCC will advise airborne
    flight crews of the possibility of a reroute and the reason. They
    will notify the crew which routes are acceptable and the additional
    flight time and fuel burn for the reroute.

Section 3Number range Level1Number range Level2Number range Level3

# Potential Benefits

Potential benefits of collaborative routing include the following:

-   Better informing users about potential flow problems that are likely
    to require rerouting or other flow management actions. This will
    allow users to prepare for possible effects on their operation in
    advance.

-   Increasing the FAA's awareness of operational factors known to users
    that should be taken into consideration during flow management
    reroute planning.

-   Reduction in FAA-airspace user voice communication workload during
    rerouting situations.

Section 4Number range Level1Number range Level2Number range Level3

# Scenario: Resolving Traffic Congestion through FAA---User Collaborative Routing

This scenario describes collaboration between the FAA and airspace users
during the resolution of a flow problem situation involving traffic
congestion. A time line of key scenario events is outlined in Figure 1.

##### ![](media/image1.pct){width="451.0in" height="181.0in"}

##### Figure 1. Time Line of Key Events

The scenario raises several issues and questions. These are listed in
the back of the document with corresponding numbers embedded in the
scenario's text. Text boxes on the left-side of each page highlight the
information exchange requirements associated with a task.

## 4.1 Number range Level3Number range Level2Problem Identification

The TMU traffic prediction capability at Kansas City Air Route Traffic
Control Center \[ARTCC\] (ZKC) forecasts significant traffic congestion
in the high altitude sectors in the southern portion of the facility's
airspace. The congestion forecast is based on projected aircraft counts
in the sectors. Congestion in two contiguous sectors is predicted to
begin in about 1 hour and persist for up to 1 hour, exceeding sector
thresholds established for that day by a substantial amount. The Traffic
Management Coordinator (TMC) advises the Area Supervisors of the
developing situation. They agree that the traffic counts need to be
reduced to acceptable levels.

The TMC and the Area Supervisors evaluate the use of vertical
resectorization, to reallocate sector workload (vertical resectorization
strategy analysis capability) and alleviate the congestion without
having to move aircraft. The results indicate this strategy will not
resolve the problem because many of the aircraft are at the same
altitudes. They recognize that whatever the selected action, it will
involve moving aircraft.

At the same time these internal FAA discussions take place, the airlines
become aware of the potential congestion problem at ZKC through the
FAA's information dissemination system**.**

**\[see Questions 1, 2, 3**\]

## 4.2 Number range Level3Number range Level2FAA-FAA Collaboration Initiated

The ZKC TMC reviews the situation with the Command Center traffic
management specialist and Memphis ARTCC (ZME's) traffic management
staff. ZME is included in the discussion because the facility is likely
to be affected by reroutes if they are used. The Command Center and the
TMCs agree the airspace users should be informed of the developing
situation. The ZKC TMC creates an FCA. The FCA conforms to the
boundaries of the two affected sectors and with start and end times
corresponding to the time the congestion is predicted to occur. The TMS
issues a congestion advisory message to all airspace users that
identifies the FCA and its location, the time period of the predicted
congestion, and the type of flow strategy the FAA may use to resolve the
situation.

## 4.3 Number range Level3Number range Level2FAA-User Collaboration Initiated

The TMS and the ZKC TMU agree that there is enough lead time before the
congestion is predicted to occur to allow for collaboration with users.
The ZKC TMC uses tools to identify the flights predicted to be affected
by the FCA. The Command Center Traffic Management System (TMS) issues an
update to the previous advisory.

**\[Questions 4, 5, 6, 7\]**

The collaboration is facilitated by the Command Center. The OCCs
choosing to participate contact the Command Center at the designated
time. The TMS has responsibility for moderating the session.

The TMS announces that from the FAA's perspective, lateral and altitude
reroutes are the preferred strategy. One OCC proposes a combination of
reroutes and airborne holding as a better option. After discussion, the
other OCCs and the FAA concur that the combination is a workable
strategy. The FAA informs the OCCs of the possible locations where the
holds are to be contained.

**\[Question 8\]**

The ZME TMU reviews its own and ZKC's predicted traffic count and
density data. The FCA's location is also reviewed. After analyzing the
information, ZME concurs that it is reasonable that some flights will
need to be rerouted into its airspace.

The ZKC TMU uses its strategy evaluation capabilities to devise a plan
for carrying out the reroute and holding strategies. The TMC examines
the available data and determines how many flights per user will need to
receive a particular constraint (either a hold or a reroute). The
allocations are communicated to the OCCs participating in the session,
along with a required response time for them to enter their preferences.

The OCCs, in turn, analyze their own data and situation and provide,
within the agreed upon time interval, their preferences for which
flights receive a specific type constraint. The preferences are
expressed in terms of which flights they prefer to be included/excluded
from rerouting, and which are their preferred choices to receive/not
receive airborne holding. Where options for preadapted Severe Weather
Avoidance Programs (SWAPs) are available, the airlines could specify
one.

For example, one OCC indicates it would prefer that a certain flight not
receive a reroute, and that another receive a hold at the airport rather
than a reroute. These preferences are based on operational
considerations known to the OCC. The information forwarded by the OCCs
is communicated to the Command Center and to ZKC's TMU electronically.
The understanding is that the TMU will use its planning tools to develop
the specific reroutes and hold assignments, taking the OCCs' preferences
into account as often as possible.

Using data link or radio the OCC would advise airborne flight crews of
the status of the NAS and the possibility of reroutes. The crew would
also be advised which routes could be accepted and which should be
refused, depending on aircraft capabilities and fuel on board.

The OCC would re-plan flights that had not departed using the same
considerations.

**\[Questions 9, 10\]**

At the same time, ZKC's TMU defines and assigns reroutes and holds to
those aircraft not part of the collaboration session. This information,
along with reroutes and holds generated through collaboration with
users, is entered into the system for strategy evaluation.

When the reroute and hold plan is completed, the TMU uses its strategy
evaluation tools to assess the effects of the reroutes and holds in the
aggregate on traffic loading in the problem sectors. The Command Center
and ZME observe the same data being examined by ZKC and agree, after
discussion, with the conclusion that the overall strategy is adequate.

**\[Question 11\]**

Based on the projected ZME count information made available from ZKC's
strategy analysis tool, the ZME TMC requests minor revisions to three of
the reroutes penetrating ZME. ZKC's TMU adjusts the ZME reroutes as
requested and re-runs the strategy evaluation. The results show that the
overall sector loading is acceptable to all FAA participants and appears
the solve the primary congestion problem. At this point, the OCCs who
have collaborated receive a notification of the aircraft-specific
reroute and hold strategy. OCC staff analyze the new routes to ensure
that fuel payloads are adequate.

## 4.4 Number range Level3Number range Level2Flow Strategy Implementation

The strategy is implemented as follows. For flights that do not have
flight plans filed, the Command Center notifies the operators and
informs them of the routes to file and the reason for the action. For
flights already having flight plans but not yet departed, ZKC TMU enters
the route amendment into the Air Traffic Control (ATC) system so that
the change is reflected in the predeparture flight plan. The operators
are automatically notified that these amendments have occurred. For
already departed flights, the flight plan amendments developed by the
ZKC TMU are transmitted to the appropriate sector controller, who
re-clears the aircraft. Sector controllers are notified of the specific
aircraft to receive airborne delays.

**\[Question 12\]**

Within 15 minutes, the traffic prediction function reflects the changes
and indicates that congestion will no longer be a factor in the sectors
that were previously projected to be overloaded.

The TMS and the ZKC TMU monitor the sector loading to ensure that the
strategy leads to the desired effects. After the activation time
expires, the FCA is canceled. The TMS issues an advisory to all NAS
users the FCA is no longer active.

To conclude, in the process of resolving the problem, the OCCs
participating in the collaboration session helped develop a strategy for
dealing with the problem; they provided their preferences as to which
aircraft are affected; and they become aware of the FAA's plans before
they actually were put into effect.

-   \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

**QUESTIONS**

-   Is this a realistic situation? If the time span for the congestion
    period were reduced, when would it be too short for user
    collaboration?

-   Would the OCCs monitor airspace congestion this early--even before
    the FAA decides that it will warrant traffic management action? If
    yes, who within the OCC would likely have this responsibility?

-   Would the airlines want to do anything based on early awareness that
    a potential congestion situation was developing? If yes, give
    examples.

-   Is this the kind of information that the OCCs would need in this
    situation?

-   Would it be desirable to have this notification accomplished via a
    website with push technology?

-   Would the same process be used if the problem were weather related?

-   How much time would this take to set up the collaboration and get
    participants on line? Is this impractical from a time standpoint?

-   Would it be simpler for the FAA to tell the OCCs which aircraft will
    have to be moved and then discuss any possible holding that would
    have to take place?

-   What happens when an airline has a serious operational constraint
    (e.g., low fuel, mechanical problems)?

-   Would it be feasible/desirable for the airlines to embed preferences
    in an individual aircraft's flight data as the preferences arise,
    even before this kind of situation materializes? If these are
    available to traffic management, they can be taken into account even
    if the OCCs are not actively involved in a collaboration session.

-   Is there ever an opportunity for the OCCs to request minor
    modifications to the reroutes developed by the FAA?

-   Should OCCs advise their pilots that the reroutes are imminent?