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Aircraft Systems and 4D Trajectory Management

September 2012

David De SmedtEUROCONTROL

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• Share and synchronise airborne and ground trajectory• Flying to “time constraints” to optimize sequences as defined by ATC

i4D concept (SESAR)

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RTA example

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Avionics Requirements for i4D

• EUROCAE WG85 / SC227, defining the worldwide standard for aircraft requirements on RNP & 4D Navigation• Annex to DO-236B / ED-75B – Minimum Aviation System

Performance Standards (MASPS)

• EUROCAE WG78 / RTCA SC214 defining the worldwide standard for Advanced ATS Data Communication• OSED – Operational Services & Environment Definition• INTEROP - Interoperability Requirements Standard• SPR - Safety and Performance Requirements • OSA - Operational Safety Assessment

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Current requirements for ETA

• ETA = Estimate Time or Arrival• ETA is an optional functionality (but required for RTA)• ETA shall be available for each point in the flight plan• ETA computation updated periodically and at any flight plan or

forecast changeNote: no definition of periodically

• Maximum error of ETA at a fix shall be less than 1% of the time of flight remaining to that fix, for the entered conditions and flight plan.Note: means perfect conditions (no forecast errors)

• ETA display resolution: 1 minute

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ETA error versus time to go

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Time to go (min.)

ETA

err

or (s

econ

ds)

ETA error DO-236B requirement (no meteo error)ETA error (10kts wind error, average Groundspeed 300kts)

ETA error example

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Current requirements for RTA

• Optional functionality• Accuracy +/- 30 seconds, 95% of the time

Note: 95% undefined• At least 1 RTA point in the flight plan (single flight plan fix),

either on ground or flight• Available climb, cruise and descent• RTA entry and display resolution: 0.1 minute• Time source synchronized with UTC is required (preferred that

equipment is synchronised to UTC from external sources, such as GPS)

• Availability determined solely by the flight time to go to the RTA fix and aircraft performance

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New proposed ETA/RTA requirements

• After initial ETA calculation, the system shall refresh the ETA calculation at least once every 60 seconds

• If time constraint is within the corresponding ETA min/max interval at the time of entry, the system shall be able to meet the required time of arrival with a 95% accuracy of :

• 30 seconds for en-route operations;• 10 seconds for arrival operations in the terminal area

• “Standard meteorological uncertainty”• Wind error < 10kts with 95% probability• Temp. error < 2kts with 95% probability

• The system shall be able to compute an ETA min/max interval for any fix of the flight plan.

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ETAmin-max (FL370-8000ft, initially 250NM, M0.75/282/250kts)

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Time to Go (min.)

Tim

e (m

in.) ETA max real

ETA max reliableETAETA min reliableETA min real

Example of ETA min/max function

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New proposed ETA/RTA requirements

• Accuracy requirement is expected to be met when a time constraint is combined with “AT OR BELOW” speed constraint(s)

• Display resolution of RTA, ETA at RTA waypoint and ETA min/max: 1 second

• Display resolution of ETA at all other fixes: 1 minute• Control function shall give priority to the guidance to altitude

and speed constraints compared to the control of the time constraint.

• Update of acceptable means of compliance to demonstrate the ETA accuracy and the Time of Arrival Control performance

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Future datalink requirements

Safety and Performance Requirements (SPR – version I):• ADS-C ATN downlink of airborne trajectory via Extended Predicted

Profile (EPP) • Sequence of 1-128 (pseudo-) waypoints including:• Latitude longitude, Fix, Level, Time, Speed, Level constraint

value, RTA, Speed restriction value• General data (A/C gross mass, speed schedule)

• ADS-C contract can be on demand, periodic or event based (EPP event type and EPP change parameters)

• ADS-C contract to downlink ETA min – ETA max• ADS-C contract to downlink meteo data• New CPDLC messages

• CROSS [position] AT [RTAtimesec]• CLEARED TO [position] VIA [routeClearanceEnhanced]

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CASSIS RTA Flight Trials (2009)

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Current RTA capability

RTA capability is today available on:

• Airbus aircraft with 2nd generation FMS (Honeywell Pegasus or Thales-GE)

• Boeing B737NG (software U7.1 or later)• Boeing B757/767 with Honeywell Pegasus FMS• Boeing B777• Boeing 747-400 with FANS 1A (s/w load 15)• MD-90 / MD-11 with Honeywell Pegasus FMS

RTA currently not available on any other aircraft types (regional, general aviation)

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IATA – EUROCONTROL Avionics Survey

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Enhan

ced V

ision

System

(EVS)

LPV S

BASGBAS

FANS 1/A - V

DL Mod

e 2

FANS 1/A H

FDL

Headu

p Disp

lay (H

UD)

ATN - VDL M

ode 2

Electro

nic Flig

ht Bag

(EFB)

FMS WPR

ADS-C

FANS 1/A SatC

om

FANS 1/A - A

CARS VDL M

ode A

Other M

ulti-F

uncti

on D

isplay

(MFD) fi

tted

RNP AR A

pproa

chADS-B

OUT

Fixed R

adius

Transit

ion (F

RT)

APV Baro V

NAV (LNAV - V

NAV)

Requir

ed Tim

e of A

rrival

(RTA)

ARINC 62

3

RNP App

roach

(LNAV)

8kHz3

3 VHF ra

dios

Fixed R

adius

Turn (R

F)

Multi M

ode R

eceiv

er - M

MRRNAV 10

GNSSMODE S

ACARS

RNAV 1 / P

-RNAV

RNAV 5IN

S - IRS

DME - DME po

sition

upda

te

Autothr

ust (A

-THR)

Autopil

ot - F

light

Directo

r VNAVEFIS

Autopil

ot - F

light

Directo

r LNAVFMS

Deg

ree

of E

quip

age

Available Planned Not Available

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SESAR WP 9.1 Flight Test and Simulations

• i4D real Flight Trial Feb 2012: RTA + datalink tested• MUAC and NORACON coupled (with Airbus cockpit) and non-coupled

simulations with mixed traffic

• MUAC observations (March 2012):• Datalink (ADS-C) very useful• RTA increased workload of controllers• uncertainty related to speed changes in RTA mode• Mixed mode difficult to handle

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Questions