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Fuel Efficient Air Traffic Control
Maryam Kamgarpour, PhD StudentClaire Tomlin, Research Adviser
John Robinson, NASA Ames Research CenterDecember 17, 2009
Outline
• Motivations for Improving Fuel Efficiency of Air Transportation
• Background on Air Traffic Control
• Study on Fuel Efficient Approach Procedure
• Conclusions and Future Work
Motivations
• Air transportation is responsible for about 25% of global warming contributions of the transportation sector in the United States[International Council for Clean Transportation, 2009]
• Air Traffic causes 4% of Radiative Forcing– This number has grown 45% since 1992 – It is predicted to grow by 150% in 2036
Improving Environmental Performance ofAir Transportation
• Use of bio fuels – Currently algae-based fuels being tested– Challenges such as energy efficiency
• Design of fuel efficient aircraft– Improving engine and aerodynamics design– Use of light weight composite material
• Design of fuel optimal routes
Average fuel burn for new jet aircraft, 1960-2008
25
50
75
100
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Year
Fu
el
bu
rn a
t d
esig
n r
an
ge
ton-km
seat-km
08
1960s
1970s
1980s
1990spost-2000
Annual Improvement Period Seat-km Ton-km 1960s 2.3% 3.6% 1970s 0.6% -0.1% 1980s 3.5% 2.5% 1990s 0.7% 0.9% post-2000 0.0% 0.3%
ICCT (2009). "Efficiency Trends for New Commercial Jet Aircraft, 1960 to 2008."
Improvement in Aircraft Design
Source: The International Council of Clean Transportation
2009
Design of Fuel Efficient Routes
• For each aircraft one can optimize: – Cruise altitude and speed– Routes based on wind and weather– Climb and descent profiles
• However, aircraft must operate within the constraints of the air traffic structure
Air Traffic - Highways in Space
Figure 1 – High-altitude jetways
Air Traffic Control
Figure 2a - Air Traffic Control Centers in the United States
Figure 2b - Northern California Terminal Radar Approach Control
Continuous Descent Approach (CDA)
Figure 3a - Continuous Descent Approach path
Figure 3b - Today’s typical descent path
Continuous Descent (Optimized Profile) Approach is assumed to reduce fuel burn and noise
Fuel Consumption RateIn Cruise Mode, fuel consumption rate decreases with increasing altitude
Figure 4 - Fuel rate in kg/nmi for B737
Standard Arrival Approach
• Heterogeneous arrivals must be separated enough to land safely
• Altitude and speed are chosen based on a common subset of aircraft
Standard Arrival Routes19000
18000
8000
7000
Figure 5 - MOD3 STAR for SFO Airport
Analyzing Benefits of Continuous Descent Approach (CDA)
Analysis Approach1 Take current aircraft arrival trajectories
2 Move the constant altitude (Level) section to a high altitude
Objective: Study fuel benefits of implementing CDA in the current airspace structure
Results on Airport Savings
AirportAverage (kg)
Maximum (kg)
Type Annual Savings $$
ATL 33 317B763 1.18E+07
DFW 38 721MD11 7.75E+06SFO 88 1623B744 1.39E+07LAX 20 507B741 1.92E+06JFK 40 479B744 7.57E+06
Scope of the Study 5 days of data for ATL, SFO, LAX airports4 days of data for DFW, 1 day of data for JFK
Constant Altitude Segments of a Standard Arrival Route
Figure 6 – Constant Altitude Segments for SFO MOD3 Arrival
Constant Altitude Segments
Figure 7 – Atlanta ATL airport constant altitude level sections from four arrival posts
Path extensions for separation result in constant altitude segments of arrival flight
Analysis of Results Implementing time-separation at higher
altitudes would not improve fuel efficiency
Figure 8 - Fuel rate kg/min for B737
Conclusions and Future Work• Continuous Descent Approach in the current
airspace restrictions will result on average savings of 50 kg fuel per flight
• Current descent approaches are based on air traffic needs for maintaining separation
• There is a trade-off between separation of aircraft and fuel savings that need to be analyzed
Current Research and Real-World
• Los Angeles LAX• Louisville • London Heathrow Airport
Atlanta ATL Airport Arrivals
STAR avg fuel (kg)
avg time (min)
number of aircraft
FLCON 28 1.62 328CANUK 29 1.40 186HONIE 18 1.41 66ERLIN 13 0.81 249
Arrivals from the East result in more fuel savings when arriving on the Westerly runways
ERLIN FLCON
HONIE CANUK
Fuel Savings based on the Standard Arrival Route
Fuel Analysis Based on Routes and Runways
Arrival towards East
FLCON
CANUKHONIE
ERLIN
Arrival towards West