RFG ASPA-S

1
RFG ASPA-SM Requirements Determination

• ASAS-TN2
• 26-28th September
• Malmo, Sweden

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
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
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 SM procedure
• Operational Hazards workshops held in March 2005
  and September 2005 with pilots and controllers

Safety Requirements
OSA
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
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
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
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
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-SM as a fast-track application

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