1. European Organisation for the Safety of Air Navigation RFG ASPA-S&M Requirements Determination ASAS-TN2 26-28 th September Malmo, Sweden

2. 2 The operational requirements Objectives: more predictable spacing, reduced controller workload, more efficient flight profiles, increase runway capacity The controller gives an aircraft a spacing value to acquire and maintain behind another aircraft Two main variants of the procedure: remain behind (same route) and merge behind (converging routes)

3. 3 Progress so far: operational requirements Mature Operational Service and Environment Description (OSED) available Convergence on almost all main issues Work continuing on clarifying operational requirements, incl: Unambiguous measurement of spacing value Relationship of ASAS with surrounding environment Current update to incorporate initial OSA and OPA findings Operational Requirements OSED

4. 4 Progress so far: safety requirements Entire ED-78A / DO-264 process applied to an airborne ASAS application Full collaboration between US and Europe OSA proposes safety objectives and safety requirements for the S&M procedure Operational Hazards workshops held in March 2005 and September 2005 with pilots and controllers Safety Requirements OSA

5. 5 Progress so far: safety requirements ED-78A severity risk table was used New row added… “Example of ASAS operational effect” to aid further safety assessment work on ASAS Safety assessment proposed new mitigation procedures (to be included in OSED as exceptions) OHA almost complete – validation by operational personnel on-going ASOR work on-going Safety Requirements OSA

6. 6 Progress so far: performance requirements OPA process carried out as per ED78A Focused on technical performance requirements (i.e. ADS-B datalink specific) Assumes ground-based performances, and voice R/T communications performances, are AS TODAY (therefore, no specific parameters were derived) Collaboration in validation from EEC and MITRE – sharing databases, calculations and results Performance Requirements OPA

7. 7 Fast-time simulation / validation ACL ADV1 ACL ADV2 From MITRE fast-time simulations Initial spacing = 110 seconds Required spacing = 110 seconds Level altitude, constant CAS for lead aircraft

8. 8 Progress so far: performance requirements Issues Operational assumptions Link between performance objectives and performance parameters The operational performance / behaviour of the aircraft in the scenario - not something previously considered in ED78A Second iteration of OPA currently underway Performance parameters include ‘maximum/minimum closure rate’; ‘spacing tolerance’; ‘stability of aircraft speeds’ etc… Definition of validation inputs to follow Performance Requirements OPA

9. 9 Lessons learnt ED78A is a good basis for assessment, but needs: To consider behaviour of aircraft for performance assessment Careful use by experts to apply various risk tables to ASAS Understanding of inter-relationship between C, N and S Some differences between US and Europe in applying methodologies have been resolved This process of learning was the purpose of choosing ASPA- S&M as a fast-track application

10. 10 The way ahead OSA to be completed and validated as soon as possible OPA is being re-drafted – materially complete by late 2005 (awaiting validation results) Further simulations to be planned through 2006, in US and Europe INTEROP work to start on completion of mature OSED and SPR