Fuel Efficient Air Traffic Control
Maryam Kamgarpour, PhD Student
Claire Tomlin, Research Adviser
John Robinson, NASA Ames Research Center
December 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 of
Air 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
Improvement in Aircraft Design
Fuel burn at design range
Average fuel burn for new jet aircraft, 1960-2008
2009
100
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%
1960s
1970s
seat-km
1980s
75
1990s
ton-km
post-2000
50
25
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005 08
Year
ICCT (2009). "Efficiency Trends for New Commercial Jet Aircraft, 1960 to 2008."
Source: The International Council of Clean Transportation
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)
Continuous Descent (Optimized Profile) Approach
is assumed to reduce fuel burn and noise
Figure 3a - Continuous
Descent Approach path
Figure 3b - Today’s
typical descent path
Fuel Consumption Rate
In 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 Routes
19000
18000
8000
7000
Figure 5 - MOD3 STAR for SFO Airport
Analyzing Benefits of
Continuous Descent Approach (CDA)
Objective: Study fuel benefits of implementing
CDA in the current airspace structure
Analysis Approach
1 Take current aircraft
arrival trajectories
2 Move the constant
altitude (Level) section to a
high altitude
Results on Airport Savings
Airport
ATL
DFW
SFO
LAX
JFK
Average Maximum Type Annual
(kg)
(kg)
Savings $$
33
317B763
1.18E+07
38
88
20
40
721MD11
1623B744
507B741
479B744
7.75E+06
1.39E+07
1.92E+06
7.57E+06
Scope of the Study
5 days of data for ATL, SFO, LAX airports
4 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
Path extensions for separation result in constant
altitude segments of arrival flight
Figure 7 – Atlanta ATL airport constant altitude level
sections from four arrival posts
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
ERLIN
FLCON
Fuel Savings based on the
Standard Arrival Route
STAR
HONIE
CANUK
avg fuel avg time number of
(kg)
(min)
aircraft
FLCON
28
1.62
328
CANUK
29
1.40
186
HONIE
18
1.41
66
ERLIN
13
0.81
249
Arrivals from the East result in more fuel savings
when arriving on the Westerly runways
Fuel Analysis Based on Routes
and Runways
ERLIN
HONIE
Arrival towards East
FLCON
CANUK
Arrival towards West