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Airborne Separation Assistance Systems(ASAS) - Summary of simulations
Joint ASAS-TN2/IATA/AEA workshopNLR, Amsterdam, 8th October 2007
Chris ShawEUROCONTROL Experimental Centre, France
European Organisation for the Safety of Air Navigation
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Contents of presentation
Introduction Radar airspace
Simulations of airborne spacing merge and remain behind in TMA
Non-radar airspace Simulations of air traffic situational
awareness for oceanic step climbs
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Introduction (1/2)
Secondary surveillance radar coverage 10,000 feet - green quadruple
Automatic Dependent Surveillance - Broadcast (ADS-B) invented 1980s.
74% of flights in Europe equipped with ADS-B Mode S extended squitter of which 79% broadcasting position (Eurocontrol, August 2007)
Benefits: Surveillance cost 1/10 of ground
based radar -> reduced navigation service charges ~30%
Wider coverage – niche areas too expensive for ground radar
Increased efficiency of flight operations enabled by airborne separation assistance system
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Introduction (2/2)
Airborne Separation Assistance System (ASAS) 1983: “Analysis of in-trail following
dynamics of Cockpit Display of Traffic Information (CDTI)”, Sorensen & Goka, NASA
2007: > 80 ASAS applications identified (Eurocontrol/FAA)
Example ASAS applications with early benefits:
Airborne spacing merge and remain behind in TMA
Airborne traffic situational awareness for oceanic step climb
© EUROCONTROL Experimental Centre
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Merge and remain behind in TMA (1/6)
Motivation Improve the sequencing of arrival flows
through a new allocation of spacing tasks between air and ground
Neither “transfer problems” nor “give more freedom” to pilots … shall be beneficial to all parties
Assumptions Air-air surveillance capabilities (ADS-B) Cockpit automation (ASAS)
Constraints Human: consider current roles and working
methods System: keep things as simple as possible
Paris Orly, 2002, source: ADP
To achieve spacing at waypoint
Merge
spacing at waypoint
Merge
To maintain spacing
Remain
To maintain spacing
Remain
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Merge and remain behind in TMA (2/6)
Development and refinement of spacing instructions and working methods
Identification of required functional evolutions (air and ground) and route structure
Aircraft under spacing
Aircraft with target selected
© EUROCONTROL Experimental Centre
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Merge and remain behind in TMA (3/6)
Assessment of feasibility, benefits and limits Representative environment
with very high traffic From cruise to final approach Nominal and non nominal
conditions (mixed equipage, go-around, emergency, radio failure, airborne spacing error, …)
Controller, pilot and system perspectives
Large panel of participants Controllers from various
ANSP (AENA, DSNA, ENAV, IAA, LFV, NATS, NAV-EP)
Pilots from Airbus and various airlines (DLH, CTN, …)
BaselineWith spacing
Distribution of inter aircraft spacing at final approach fix
9060 120 150 180
Num
ber o
f airc
raft
22
23
24
25
26
27
Baseline
Number of aircraft passing final approach fix
(period 45min)
With spacing
Flown trajectoriesBaseline
Flown trajectoriesWith spacing
© EUROCONTROL Experimental Centre
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Merge and remain behind in TMA (4/6)
EUROCONTROL-DSNA Project, October 2005 – February 2007Evaluation of operational benefits of airborne spacing sequencing and merging for Paris Arrivals
Charles de Gaulle North – partial equipage – time gain
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A new RNAV route structure?
A preliminary step to prepare implementation of airborne spacing
A transition towards extensive use of P-RNAV
A sound foundation to support further developments such as CDA (continuous descent) and 4D (target time of arrival)
Merge and remain behind in TMA (5/6)
0
20
40
60
80
100
120
0 10 20 30 40 50 60
Altit
ude
(feet
x10
0)
Distance to final approach fix (NM)
Baseline
New route structure
0
20
40
60
80
100
FinalFr
eque
ncy
occu
panc
y (%
) New route structureBaseline
Approach
© EUROCONTROL Experimental Centre
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Merge and remain behind in TMA (6/6)
Point merge preliminary fast-time simulation results (RAMS platform)
4 Initial approach fixes 1 runway 1 hour traffic ~30 aircraft with
20% heavy/80% medium mix 2 controllers Continuous descent approach
from 12,000 -> 3,000 feet Distance range 60-90 NM
Point Merge Radar Vector 400
600
800
1000
1200
1400
1600
1800
2000
2200
2400
Tot
al f
uel c
onsu
mpt
ion
in T
MA
per
airc
raft
[kg
]
© EUROCONTROL Experimental Centre
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Oceanic step climbs (1/3)
FL340
FL360
FL350
> 10 mins > 10 mins
ATSA-ITP
Criteria
• Aircraft at FL340 would like to climb …..• But standard longitudinal separation does not exist at level above • Crew request a step climb with airborne traffic situation awareness
5 mins
ASSTAR step climb with airborne traffic situation awareness
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Oceanic step climbs (2/3)
Today over North Atlantic average 0.2 step climbs per flight recorded
Fast time simulations show with airborne traffic situation awareness number of step climbs
per flight could be 2 or more.
~75% of climb requests could be satisfied immediately and at least 93% satisfied eventually.
ASSTAR fast time simulations
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Oceanic step climbs (3/3)
Costs Implementation costs per aircraft
45,000 € retrofit 35,000 € forward fit
Maintenance costs per annum 1,200 € retro fit 1,500 € forward fit
Benefits 150 Kg fuel saved per single oceanic transition 54,000 € per aircraft per year 0.6% reduction in emissions
Payback period 0.9 years retro fit 0.7 years forward fit
(Assuming 2 transitions a day and 0.5 € per kilogram)
Cost benefit analysis by BAE Systems
D5.3 (http://www.asstar.org/)