presented on react workshop, seville > june 24-25, 2008 slide 1 > future air ground...

> Future Air Ground Integration > A. KuenzPresented on REACT Workshop, Seville > June 24-25, 2008

FAGI – Future Air Ground Integration

Alexander Kuenz,Institute of Flight Guidance, DLR Braunschweig, Germany

Presented on REACT Workshop 2008, Seville


Future Air Ground Integration - FAGI

DLR-funded project

Duration Jan 2007 – Dec 2009

Involved Departments:

Institute of Flight Guidance/Braunschweig

Institute of Communication and Navigation/ Oberpfaffenhofen+Neustrelitz

Equipment: Flight Operations/Braunschweig and Institute of Flight Systems/Braunschweig

First concept finalized, first validation by experts done

Development of tools in progress

Final validation by ATM-simulations in 2009


Environmentally friendly

procedures in terms of

NOx and CO2 emissions

Noise emissions andimmisions on the ground

Fuel efficiency

Achieved by

Efficient usage of engines

Low drag aircraft configuration

Flying high altitudes

Motivation: A Definition of „Green Trajectories“

} Arrival: Continuous Descent Approaches (CDA)


3°

DLR`s Advanced Continuous Descent Approach

Distance to Touchdown

Alti

tude

CFL

No level flight from Top of descent to

touchdown

Engines idle

…but great demands on- trajectory prediction and- guidance precision

Once in descent, it is hardly possible to react on ATC instructions


Trajectory Prediction and Guidance using DLR’s Advanced Flight Management System (AFMS)

Altitude and Time

constraints

List of Waypoints

Weather Forecast

Aircraft Model

Descent Parameter

AFMS Cockpit

ATTASG

uida

nce

Com

man

ds


Flight and Simulation TrialsVFW614 (ATTAS) Airbus A330 FFS (ZFB)

Adaptation to aircraft type via Base of Aircraft Data provided by Eurocontrol


Deviations from planned 4D-trajectory

Deviations may occur due to

Insufficient or imprecise aircraft performance data

Jitter in the configuration points

Inaccurate weather forecast

…

Possible reactions are to

Hold the correct speed and cumulate an altitude error

Hold the correct altitude and cumulate a speed error

Average altitude and speed error

The AFMS tries to hold the time deviation at minimum.


ATTAS A330

LDLP auto. +/-5s, +/-100ft +/-3s, +/-100ft

LDLP man. +/-6s, +/-100ft +/-3s, +/-100ft

CDA auto. +/-5s, +/-100ft +/-2s, +/-100ft

CDA man. +/-5s, +/-100ft +/-4s, +/-100ft

SCDA auto. +/-8s, +/-150ft +/-4s, +/-100ft

SCDA man. +/-9s, +/-150ft +/-5s, +/-150ft

Two approaches differed (10 seconds time precision):

Constant downdraft in the lee of Harz mountains, but the weather forecast does not contain vertical wind components

A mini jet stream was encountered between 10000ft and 5000ft without a sampling point for the weather grid in-between.

Inaccurate weather is the main factor for deviations!

Results of automatic and manual ATTAS/A330 approaches (>30 NM)


LDLPACDA

Noise footprints of LDLP and ACDA (SIMUL)

Approaches with Airbus A320 to 25R in Frankfurt Main via Gedern

RW25R

REDGO (FAF)

GED

0 2 4 6 8 10 12 14 16 NM

0

2

4

6

8

10

NM


Two Aircraft landing in Frankfurt…

Capacity Driven Early Merging:

Same Lateral Route

Same Altitude Profile

Same Speed Profile

Assuming different types of aircraft, ACDAs are unsuitable in high traffic situations


Requirements to handle green trajectories in high traffic TMAs:

Trajectory-based handling to benefit from the described airborne capabilities User preferred Trajectory

Mixed traffic support for FMS-equipped and unequipped aircraft

Late merging to fly the aircraft’s optimum profile as long as possible

Time-based separation could even improve today’s capacity

Emergency handling and flexible planning for short term departures


E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12

Late Merging Point,Time-based separation to

threshold

StrategicPath-

Stretching

10

100

>5500ft for Trombone AC

Dynamic 4D Routes for

dynamic entries

NM

Extended TMA

Radius 80-120NM to allow time variation by speed changes

Strategic path stretching if speed variation is insufficient

DLR’s approach for a Trajectory Based TMAhandling


E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM

Late Merging Point

Merging just before final approach (e.g. G/S intercept)

Time based merging, time constraint for every approaching aircraft



E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM

RTAs for the Late Merging Point are assigned when entering the E-TMA



E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM

Static E-TMA entries

Aligned to the main traffic routes

Keep TMA structured and clearly arranged



E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM

Dynamic E-TMA entries

Are provided if possible

For aircraft entering between static entries



E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM

Procedural Separation before merging allows flying aircraft optimized vertical and speed profiles



E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM

FMS-equipped aircraft can fly their predicted trajectory on their own and fulfill the time constraint at the Late Merging Point

10:05:37 +/-5s



E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM

Unequipped aircraft are supposed to be integrated by means of a ground based guidance module.

A trombone path stretching area helps to improve accuracy.

10:07:20 +/-?s



E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM

Trombone also used for

Insertion of short term departures

Equipped aircraft violating their constraints

Insertion of emergency delays

E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM



DLR’s approach for a Trajectory Based TMA handling

E-TMA

Static (standard)

E-TMA entries

enroute

11

12

12


threshold

StrategicPath-

Stretching

10

100



dynamic entries

NM

Procedural separation between direct and trombone aircraft:

Equipped aircraft perform shallow descents

Trombone aircraft are forced to stay above at intersections

The proposed E-TMA structure is promising but not verified yet!


TP Air-Ground Synchronization: Requirements

Onboard:

Highly accurate 4D trajectory flyable fulfilling predefined constraints

High Mid-term reliability, no update necessary in most cases for last 100NM

On Ground:

4D trajectory needed

for Trajectory Based Conflict Detection and Resolution

for Conformance Monitoring

Required lateral and time accuracy is medium to high

Required vertical accuracy is low due to route structure


TP Air-Ground Synchronization: Prediction

No need for a high bandwidth data linkAir and Ground Trajectory predicted with preferably same input dataList of Waypoints exchanged by Route Name via R/TConstraints are defined by Route + one Time constraint at Late-Merging PointAircraft Performance Model from BADADescent Parameter via R/TSome inputs not available on ground: Same Weather, Aircraft’s Weight, Turn Radius, Airliner’s specific settings…

Altitude and Time

constraints

List of Waypoints

Weather Forecast

Aircraft Model

Descent Parameter

AFMS Cockpit

ATTAS

Gui

danc

e C

omm

ands


TP Air-Ground Synchronization: Assumptions

Lateral assumptions:

Route based on straights and curved segments

Bank-Angle: Speed & Bank Turn-Radius

Vertical assumptions:

Arriving aircraft do not climb in E-TMA

Aircraft descend as late as possible flying the descent profile

Speed assumptions:

Arriving aircraft do not accelerate in E-TMA

Arriving aircraft decelerate as late as possible to reach RTA at LMP

Learn from aircraft’s progress: when deviations occur, regenerate!

710

IAS


Conclusion

ACDA flight and simulation trials with ATTAS & A330 proved high accuracy of DLR’s AFMS in manual and automatic mode

Inaccurate weather forecast is main factor for deviations

Achieved precisions of 150ft altitude and 5 seconds time deviation for idle descents are good enough for trajectory based TMA-handling

A trajectory based TMAconcept was introducedproviding operationsfor mixed traffic and emergencies

No need for a high band-width data link, TP synchron-ization can be done viaR/T.


Thanks for your attention! Questions?

presented on react workshop, seville > june 24-25, 2008 slide 1 > future air ground...

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