1. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 ASAS-SEP Applications Airborne Implementation Overall Architectural Considerations

2. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Context Main purposes –elaborate a more optimal or efficient manoeuvre (than the one the ATCO would have used) defined by the on-board ASAS algorithm –reduce the ATCO workload (by withdrawing separation monitoring during the manoeuvre) Principle of solution –To delegate the separation manoeuvre execution from ATCO to flight crew

3. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Fundamental principles ASAS-SEP manoeuvre involves –the clearance aircraft –and only one single designated target aircraft, having a steady trajectory, the crew of which has no involvement in the manoeuvre –ATCO remains responsible for separation with respect to the other aircraft in the sector Once the separation is delegated, ATCO does not monitor the manoeuvre Regulatory separation is maintained –NB : separation standards could be changed (reduced)

4. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Actors & equipments during ASAS- SEP manoeuvre Clearance A/C Target A/C ATC ADS-B Out Nav Data ADS-B In ASAS Function Trajectory management ATC Communication

5. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Constraints on Navigation Data Clearance A/C Target A/C ATC ADS-B Out Nav Data ADS-B In ASAS Function Trajectory management ATC Communication

6. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Constraints on Navigation Data Manoeuvre elaboration and execution rely strongly on clearance aircraft and target aircraft positionning integrity and continuity (quality) Since the ATC does not monitor the separation between clearance and target aircraft during the ASAS manoeuvre, the entire safety case relies on the ASAS on-board implementation As a consequence (hypothesis) : –either intrinsic high quality positionning systems (both clearance aircraft and target aircraft) –or capability to monitor position data against an independent source (at clearance aircraft) –robust ADS-B datalink for ensuring continuity of ADS-B transmission

7. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Constraints on ASAS Function Clearance A/C Target A/C ATC ADS-B Out Nav Data ADS-B In ASAS Function Trajectory management ATC Communication

8. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Constraints on ASAS-SEP function Crew interface & ASAS function –Crew shall be provided with traffic situation display with capability to designate a target capability to initiate and manage the manoeuvre –ASAS function shall elaborate a manoeuvre that guarantees the separation with target aircraft during the entire manoeuvre (at initial conditions) –ASAS function shall update the manoeuvre continuously taken into account current conditions As a consequence –Such features are safety critical and shall be integrated into cockpit and avionics design with features compatible with other functions having similar criticality

9. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Constraints on Trajectory Management Clearance A/C Target A/C ATC ADS-B Out Nav Data ADS-B In ASAS Function Trajectory management ATC Communication

10. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Trajectory management Execution of manoeuvre –Trajectory management should be predictible (standardisation required ?) for ATC in order to rely on for separation management with surrounding traffic and for responsibility reversion to ATC in case of aborted manoeuvre simple, probably automated, for the crew => manual intervention for corrective actions only if compatible with safety and performance requirements within a well-defined ASAS procedure volume that ATC can rely on As a consequence –manoeuvre should be managed by airborne trajectory management means or by interfacing to such means which satisfies appropriate safety requirements

11. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Constraints on ATC Communication Clearance A/C Target A/C ATC ADS-B Out Nav Data ADS-B In ASAS Function Trajectory management ATC Communication

12. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 ATC Communication ATC dialog during ASAS manoeuvre initiation phase requires –several information elements to be exchanged –integrity of communicated data shall be ensured As a consequence –CPDLC datalink should be preferred against voice –implementation of new ASAS messages would then be necessary (id voice phraseology)

13. 4 th Workshop, Amsterdam, 23 rd -25 th April 2007 Conclusions Airborne implementation requires further study in the following areas : Integrity / Continuity of position at both target aircraft and clearance aircraft level (no identified current activities in this area for ASAS-SEP) High continuity of broadcast datalink Standardisation of ASAS-SEP procedures and operation