ASSTAR Airborne Separation Operations in Oceanic Airspace Bob

ASSTAR Airborne Separation Operations in Oceanic Airspace Bob Mc. Pike, NATS ASAS-TN 2 Conference Glasgow, September 2006

Overview · Background to oceanic operations · ASAS operations to improve flight flexibility · ASAS operations to manage airspace congestion 2

Oceanic Communications · No VHF Radio or radar cover most of the North Atlantic Region (NAT) · Voice communications provided by High Frequency (HF) Radio · HF subject to weather effects · – Audibility can be limited – Sometimes communication is impossible So ATC issues strategic clearances – Issued prior to entering an oceanic Flight Information Region (FIR) – Extend from Oceanic Control Area (OCA) entry to landfall – Long-term conflict prediction used to ensure no separation loss over whole route 3

Oceanic Separation Standards · Separation standards governed by various uncertainties: – Communication unreliability – Navigational accuracy – Accuracy of forward estimates (driven by weather forecasts). . . so separation standards are very large 10 mins 1000 ft 15 mins 60 miles 4

ASAS in Oceanic Airspace · ASAS concepts under consideration by ASSTAR for oceanic airspace – In-Trail Procedure (ATSA-ITP and ASEP-ITP) – In-Trail Follow (ASEP-ITF) – Self-Separation on a Free-Flight Track (SSEP-FFT) · Status – Concepts and procedures defined – Simulations will be conducted in Amsterdam November 2006 to March 2007 5

In-Trail Procedure • Crew Aircraft But standard request at FL 340 longitudinal an ITP would Climb like separation to climb …. . does not exist at level above > 10 mins FL 360 FL 350 ATSA-ITP 5 mins Criteria FL 340 6

In-Trail Follow • Exit 5 minutes Airborne Climb Second In-Trail Oceanic Approved, Separation Follow climb Separation : No Airspace approved cancelled standard Maintaining maintained Established: –Maintaining longitudinal In-Trail over In-Trail extended separation Airborne ITF Follow Separation period Separation FL 360 FL 350 FL 340 5 mins ITF 7

Self-Separation on a Free-Flight Track · Concept still in the early stages of development · FFT is an OTS track reserved for ASAS-capable aircraft · Aircraft on the track can change speed and level at their own discretion . . . but no lateral flexibility allowed · Aircraft requires downstream clearance to re-enter managed airspace 8

Using ASAS to manage airspace congestion ·Oceanic/Domestic Interface - a Plumbing Problem? – Narrow ‘pipes’ in European/North American regions – European pipework highly complex (lots of crossing and converging traffic) 9

Traffic Concentration 24 May 2006 10

Traffic Streaming 11

Tactical re-routes in the NAT 4 minutes 15 minutes ITF 12

Thank you for listening bob. mcpike@nats. co. uk 13