Controlled Time of Arrival (CTA) Feasibility Analysis

David De Smedt Eurocontrol Greg McDonald, Jesper Bronsvoort Airservices Australia

ATM Seminar 2013, Chicago U.S.A.

Drivers for RTA

The SESAR ATM Master Plan states that “Step 1, Time-based Operations, is the building block for the implementation of the SESAR Concept and is focused on flight efficiency, predictability and the environment”. NextGen Implementation Plan 2012 states that “Enhancements to the navigation capabilities of aircraft, RNAV/RNP with Time of Arrival Control (TOAC) in the descent phase, will begin to increase benefits of trajectory operations through the adaptability of the aircraft trajectory to enable operational predictability and arrival accuracy of aircraft”

Context of the Paper? • The aircraft can accurately achieve a time • Aircraft separation infringement risk at 5% • But does RTA approach work for a sequence?

Stockholm RTA trials 2006 et al.

Controlled Time of Arrival Spacing Analysis 2011.

Standard Arrivals to Melbourne Structured Terminal Area Each of the arrival paths to Melbourne is a published procedure issued by ATC and entered to the FMS prior to Top Of Descent If the cruise sequencing has been done correctly, the aircraft flies the STAR path to the threshold uninterrupted.

No. of operations per hour YMML R34 - 08 August 2012

0

5

10

15

20

25

30

35

40

45

07-08-1214:00

07-08-1218:00

07-08-1222:00

08-08-1202:00

08-08-1206:00

08-08-1210:00

08-08-1214:00

UTC

No. o

f ope

ratio

ns /

hour

Arrivals Departures All

Normally Ops are Multiple Runway Strong Northerly on August 8th 2012

Demanded Single Runway Ops

Enroute Autonomously Achieve the AMAN Delay

00:18:03

20

WENDY

All Runways

ARBEY

All Runways

3 20 VOZ310 27 40

0 0 VHTJJ 34 36

1 3 VHOGL 34 34

1 3 VHZXA 16 30

-2 0 VHTJF 16 28

25

42 27 EA363 10 7

35 27 VHMZU 2 1

33 27 KD566 4 2

31 27 KD452 3 3

29 27 EA056 0 0

•Sequence Number

•Landing Runway

•Callsign

•Total Delay

•Delay Achieved

HORIZONTAL VIEW

WENDY

ARBEY

WAREN

LIZZI

BADGR

-41

-40

-39

-38

-37

-36

-35

-34

139 140 141 142 143 144 145 146 147 148 149 150

Longitude

Latit

ude

VOZ866

QFA451

VOZ278

VOZ868

JST971

JST451

VOZ1377

VOZ1331

QFA476

JST949

QFA457

VOZ870

MAS129

QFA692

QFA631

UAE407

VOZ874

QFA459

QFA833

VOZ342

QFA694

TGW623

RXA3683

VERTICAL VIEW

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250 300

Distance to Go (NM)

Flig

ht L

evel

VOZ866

QFA451

VOZ278

VOZ868

JST971

JST451

VOZ1377

VOZ1331

QFA476

JST949

QFA457

VOZ870

MAS129

QFA692

QFA631

UAE407

VOZ874

QFA459

QFA833

VOZ342

QFA694

TGW623

RXA3683

HORIZONTAL VIEW

WENDY

ARBEY

WAREN

LIZZI

BADGR

-41

-40

-39

-38

-37

-36

-35

-34

139 140 141 142 143 144 145 146 147 148 149 150

Longitude

Latit

ude

RXA3683

JST479

TFX152

VOZ236

QFA455

QFA463

VOZ878

QFA635

JST525

SQC7297

JST712

VOZ746

QFA483

CSN343

VOZ882

RBA53

TGW631

QFA465

VOZ346

QFA768

QFA134

QFA467

QTR030

VERTICAL VIEW

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250 300

Distance to Go (NM)

Flig

ht L

evel

RXA3683

JST479

TFX152

VOZ236

QFA455

QFA463

VOZ878

QFA635

JST525

SQC7297

JST712

VOZ746

QFA483

CSN343

VOZ882

RBA53

TGW631

QFA465

VOZ346

QFA768

QFA134

QFA467

QTR030

First Hour Traffic Actual Trajectories

Second Hour Traffic Actual Trajectories

Would the RTA Solution Work? Assumptions • Same traffic but different profiles • Aircraft to meet actual landing times • No lateral delay • 200nm sequencing horizon

Hand to David to explain his magic

Research Questions 1. Does the assumed 200NM sequence horizon provide

enough control authority for the FMS to use the RTA function?

2. What is the impact of airborne RTA control on legacy arrival manager systems on the ground?

3. Can the traditional “first-come-first-served” methodology still be applied?

4. How many conflicts do occur when CTAs are used in an arrival flow?

5. Can the application of CTA successfully resolve a sequence for an actual traffic scenario without controller intervention?

Fast-time simulation model • BADA 3.7 aerodynamic data

• Enhanced Trajectory Predictor

• Modeling of wind gradient • Modeling of turns • Modeling of non-ISA temperature profiles • Altitude based wind and temp. model • Modeling of Vertical Speed and/or Flight Path Angle • Modeling of Altitude and Speed Constraints

• Using real speed envelopes from Flight Crew Operating manuals

Simulation scenarios 1. Baseline scenario • recorded arrival flows into Melbourne airport within

200NM during 2 hour medium to high density operation 2. CTA scenario • initial conditions from baseline scenario • landing times of baseline applied as CTA • no lateral patch stretching

3. CTA + modified sequence scenario: • same as CTA scenario • freely allocation of landing slots to arriving aircraft

Linear holding 1/3

Step descent at low speed

Cruise

Path stretching

Linear holding 2/3 Additional time compared to 1h of cruise at FL370

0

50

100

150

200

250

300

350

400

200 250 300 350 400 450 500

TAS (kts)

FL

1h+30'

+5'

Linear holding 3/3

% fuel flow increase compared to minimum fuel flow for flight at green dot speed

Source: “Getting to grips with fuel economy”, Issue 3, July 2004, Airbus

HORIZONTAL VIEW

WENDY

ARBEY

WAREN

LIZZI

BADGR

-41

-40

-39

-38

-37

-36

-35

-34

139 140 141 142 143 144 145 146 147 148 149 150

Longitude

Latit

ude

VOZ866

QFA451

VOZ278

VOZ868

JST971

JST451

VOZ1377

VOZ1331

QFA476

JST949

QFA457

VOZ870

MAS129

QFA692

QFA631

UAE407

VOZ874

QFA459

QFA833

VOZ342

QFA694

TGW623

RXA3683

Results baseline 1

VERTICAL VIEW

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250 300

Distance to Go (NM)

Flig

ht L

evel

VOZ866

QFA451

VOZ278

VOZ868

JST971

JST451

VOZ1377

VOZ1331

QFA476

JST949

QFA457

VOZ870

MAS129

QFA692

QFA631

UAE407

VOZ874

QFA459

QFA833

VOZ342

QFA694

TGW623

RXA3683

Results baseline 1

HORIZONTAL VIEW

WENDY

ARBEY

WAREN

LIZZI

BADGR

-41

-40

-39

-38

-37

-36

-35

-34

139 140 141 142 143 144 145 146 147 148 149 150

Longitude

Latit

ude

VOZ866

QFA451

VOZ278

VOZ868

JST971

JST451

VOZ1377

VOZ1331

QFA476

JST949

QFA457

VOZ870

MAS129

QFA692

QFA631

UAE407

VOZ874

QFA459

QFA833

VOZ342

QFA694

TGW623

RXA3683

Results CTA 1

VERTICAL VIEW

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250 300

Distance to Go (NM)

Flig

ht L

evel

VOZ866

QFA451

VOZ278

VOZ868

JST971

JST451

VOZ1377

VOZ1331

QFA476

JST949

QFA457

VOZ870

MAS129

QFA692

QFA631

UAE407

VOZ874

QFA459

QFA833

VOZ342

QFA694

TGW623

RXA3683

Results CTA 1

HORIZONTAL VIEW

WENDY

ARBEY

WAREN

LIZZI

BADGR

-41

-40

-39

-38

-37

-36

-35

-34

139 140 141 142 143 144 145 146 147 148 149 150

Longitude

Latit

ude

VOZ866

VOZ868

VOZ278

QFA451

JST971

VOZ1377

VOZ1331

QFA476

JST451

JST949

MAS129

VOZ870

QFA692

UAE407

QFA457

QFA631

QFA459

VOZ874

QFA833

QFA694

VOZ342

TGW623

RXA3683

Results CTA + mod. seq. 1

VERTICAL VIEW

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250 300

Distance to Go (NM)

Flig

ht L

evel

VOZ866

VOZ868

VOZ278

QFA451

JST971

VOZ1377

VOZ1331

QFA476

JST451

JST949

MAS129

VOZ870

QFA692

UAE407

QFA457

QFA631

QFA459

VOZ874

QFA833

QFA694

VOZ342

TGW623

RXA3683

Results CTA + mod. seq. 1

HORIZONTAL VIEW

WENDY

ARBEY

WAREN

LIZZI

BADGR

-41

-40

-39

-38

-37

-36

-35

-34

139 140 141 142 143 144 145 146 147 148 149 150

Longitude

Latit

ude

RXA3683

JST479

TFX152

VOZ236

QFA455

QFA463

VOZ878

QFA635

JST525

SQC7297

JST712

VOZ746

QFA483

CSN343

VOZ882

RBA53

TGW631

QFA465

VOZ346

QFA768

QFA134

QFA467

QTR030

Results baseline 2

VERTICAL VIEW

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250 300

Distance to Go (NM)

Flig

ht L

evel

RXA3683

JST479

TFX152

VOZ236

QFA455

QFA463

VOZ878

QFA635

JST525

SQC7297

JST712

VOZ746

QFA483

CSN343

VOZ882

RBA53

TGW631

QFA465

VOZ346

QFA768

QFA134

QFA467

QTR030

Results baseline 2

HORIZONTAL VIEW

WENDY

ARBEY

WAREN

LIZZI

BADGR

-41

-40

-39

-38

-37

-36

-35

-34

139 140 141 142 143 144 145 146 147 148 149 150

Longitude

Latit

ude

RXA3683

JST479

TFX152

VOZ236

QFA455

QFA463

VOZ878

QFA635

JST525

SQC7297

JST712

VOZ746

QFA483

CSN343

VOZ882

RBA53

TGW631

QFA465

VOZ346

QFA768

QFA134

QFA467

QTR030

Results CTA 2

VERTICAL VIEW

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250 300

Distance to Go (NM)

Flig

ht L

evel

RXA3683

JST479

TFX152

VOZ236

QFA455

QFA463

VOZ878

QFA635

JST525

SQC7297

JST712

VOZ746

QFA483

CSN343

VOZ882

RBA53

TGW631

QFA465

VOZ346

QFA768

QFA134

QFA467

QTR030

Results CTA 2

HORIZONTAL VIEW

WENDY

ARBEY

WAREN

LIZZI

BADGR

-41

-40

-39

-38

-37

-36

-35

-34

139 140 141 142 143 144 145 146 147 148 149 150

Longitude

Latit

ude

RXA3683

VOZ236

JST479

QFA455

TFX152

QFA463

VOZ878

SQC7297

QFA635

JST525

VOZ746

JST712

CSN343

RBA53

VOZ882

QFA483

TGW631

QFA465

VOZ346

QFA768

QFA134

QFA467

QTR030

Results CTA + mod. seq. 2

VERTICAL VIEW

0

50

100

150

200

250

300

350

400

450

0 50 100 150 200 250 300

Distance to Go (NM)

Flig

ht L

evel

RXA3683

VOZ236

JST479

QFA455

TFX152

QFA463

VOZ878

SQC7297

QFA635

JST525

VOZ746

JST712

CSN343

RBA53

VOZ882

QFA483

TGW631

QFA465

VOZ346

QFA768

QFA134

QFA467

QTR030

Results CTA + mod. seq. 2

Video baseline 1

Video CTA + mod. seq. 1

Effect of ETA window

Reduced speed window ⇒ defining reliable ETAmin-max

Full speed window ⇒ defining real earliest-latest time window or real ETAmin-max

Quantification of results 1/2

Quantification of results 2/2

CTA reliable ETA window

CTA real ETA window

CTA + mod. seq. real ETA window

Dev 01:19:45 00:39:16 00:10:12

AVG X 1.21 0.94 0.82

STD X 0.71 0.48 0.21

minmax

min

ETAETAETACTAX−

−=)ETACTA,0(MaxDev max−=

Conclusions 1/3 Simulation conditions:

• Single RWY operation in Melbourne • Real traffic sequence (45 aircraft during 2 hours) • Recorded positions and times at 200NM from Melbourne

during 2 hours

Using CTA and a modified sequence yielded: • Distance reduction of 484 NM (5%) • Fuel consumption reduction of 1317 kg (3%) • Fuel consumption reduction of 29 kg per aircraft

Conclusions 2/3 Operational implications:

• Application of CTA with modified arrival sequence produced

a more efficient and orderly flow of traffic, BUT… • RTA based speed control is unlikely to be sufficient to solve

a sequence of arriving aircraft in a high density scenario • Horizon of 200NM did not provide enough speed control

authority for all aircraft • Preconditioning (extended horizon) ⇒ ATC coordination! • Alternatively combined measures (speed control and linear

holding or path stretching) • “first-come, first-serve” ⇒ optimized CTA sequence • Reduced ETA window aggravated situation

Conclusions 3/3 Overall:

• Airborne RTA is one building block in the total solution to

Trajectory Based Ops • Combined Air and Ground systems approach • Mixed mode environment

Questions