ECLECTIC: What is it?

CENTRE D'ETUDESDE LA NAVIGATIONAERIENNE

ASAS-TN, 2nd workshop - Malmö 6 ~ 8 october 2003 page 1

Electronic separation Clearance Enabling the Crossing of Traffic under Instrument meteorological

Conditions



ECLECTIC: What is it? To assess operational feasibility and acceptability

of ASAS Crossing Procedures (ACP) Procedures which allow the flight crew to provide separation

with respect to one aircraft designated by ATC The controller remains responsible for separation of other

aircraft Airborne separation Minima

A CENA Project : prospective study for Package 2 European context : EEC, NUP II, MFF, MA-AFAS



ECLECTIC: How? First step

A demonstrator running on PC unit Several scenarios of crossing

Different crossing angles Different altitudes and speeds Different horizontal separation at CPA before ASAS manoeuvre

Controller radar display Flight deck MMI example (CDTI + control unit) Automatic or manual initiation of ACP and piloting (through

pseudo A/P)

Further steps Experimentations with traffic simulator and real controllers Traffic scenarios with several aircraft



ECLECTIC: An example of ACP ASAS « lateral crossing procedure »:

Aircraft cleared for ACP

Crossed (« designated »)

aircraft

Manoeuvring envelope

« Clear of Traffic »

New « ACP » trajectory

Initial planned trajectory

New waypoints introduced by ASAS

algorithms



Considerations & assumptions ACP considered as a « standard » procedure

Proposed by ATC If impossible, flight crew will advise ATC immediately

No monitoring by ATC ACP is considered as safe as today’s procedures

Airborne separation value may be different from the radar one

Radar separation minima are not the same everywhere The airborne value may depend on the equipment

Contingency in case of « ASAS unavailability » The ACP abortion does not mean immediate risk of collision ATC should be able to recover ATC may use half vertical separation as a last resort ACAS



Scenarios Different crossing angles:

« Head-on » « crossing » « Same route »



Different solutions Pass behind…

Or in front



Issues The phraseology must remain simple and robust The « other aircraft » designation is still an open

issue Unambiguous Must not generate confusion with traffic not involved

The need to lock the navigation of the other aircraft and to advise it about the ASAS crossing, to be discussed

End of procedure: At « Clear of Traffic », or After resuming navigation?



Example of phraseology Atc: ABC123, for ASAS separation, identify traffic <other

a/c id *, position> Pil : Traffic <other a/c id> identified, ABC123 Atc: ABC123, pass behind traffic, maintain airborne

separation, report clear of traffic (or : resuming navigation)

Pil : Passing behind traffic, maintaining airborne separation, ABC123

… ( the controller is NOT required to monitor the crossing)

Pil : ABC123, clear of traffic (or: resuming navigation) Atc: ABC123, roger.

* note : the unambiguous identification of the other aircraft is still an open issue, which may be solved through data-link communication



How does it work ?

Traffic scenario Simplified aircraft simulator

ASAS algorithm + parameters computes alternative routes for separation

The aircraft is piloted in real time though A/P commands

The HMI (ND) is for demo and experimentations purpose, not a proposal for implementation



Crossing at 120° angle (1/6)The other aircraft has been identified

Its flight path is displayed (magenta track)

Current distance between aircraft: 153NM

(display range 320NM)



Crossing at 120° angle (2/6) The ASAS system

has been switched on: an alternative route (with offset solution) is proposed to the pilot (yellow dotted line)




Crossing at 120° angle (3/6) The alternate route is

activated : its colour is changed to green

The separation is assured at the required value (here: 8NM)




Crossing at 120° angle (4/6) The aircraft is

following the new route




Crossing at 120° angle (5/6) (display range

40NM)



Crossing at 120° angle (6/6) Aircraft have passed

the CPA at (slightly less than) the required separation value…

Own aircraft can resume its navigation (here, « direct to »)




First results of achieved separation Parameters:

Offset solution Required separation value : 8NM Angle of deviation :

60° (crossings at 23°) 30° (crossings at other angles)

Crossings : 23° : 60° : 120°:

Head-on



Further work Other parameter values

5NM, 3NM as examples for separation Other angles of deviation « Pass in front »

Other algorithms One waypoint solution Open angle of deviation

Manoeuvring Envelope

Simulations

ECLECTIC: What is it?

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