aircraft operations environmental assessment: cruise
TRANSCRIPT
Aircraft Operations Environmental Assessment: Cruise Altitude and Speed Optimization
ASCENT Project 15
Project managers: Chris Dorbian, FAAStephen Merlin, FAA
Principal investigators: R. John Hansman, MITTom Reynolds (Lincoln Laboratory)
This work is funded by the US Federal Aviation Administration (FAA) Office of Environment and Energy as a part of ASCENT Project 15. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the FAA or other ASCENT
Sponsors.
Project Overview
• Funding: FAA Office of Environment & Energy (FAA/AEE)
• High-Level objective: Identify & evaluate operational mitigations to reduce environmental impacts of aviation in the near/mid-termwith minimal implementation barriers
• Prior work: Identified/evaluatedover 60 mitigations
• Current research focus:Quantify benefits and barriersto implementation of:– Cruise Altitude and
Speed Optimization(CASO)
– Delayed DecelerationApproach (DDA)
Surface (S):
16 mitigations
Departure (D):
11 mitigations
Approach (A)
& Landing (L)
9 mitigations
Cruise (C):
14 mitigations
Miscellaneous (M): 11 mitigations
ORIGIN
AIRPORT
DESTINATION
AIRPORT
Cruise Altitude and Speed Optimization: Overview
• Fuel burn reduction important for airlines, regulators, and society
− Economics
− Environmental impact
• 2012 Radar analysis shows 56% of domestic flight time spent in high-altitude cruise
• Efficiency Metric: “Specific Ground Range”
− Maximizes ground distance per unit of fuel consumption
− Accounts for wind and temperature
• Typical airliner cruise conditions are not fuel-optimal with respect to speed and altitude
− Opportunities in flight planning, dispatch, and cockpit procedures
− Potential applications in the NextGen ATM framework
Typical Narrow Body JetEfficiency Contours
Typical Operating
Regime(fast,
off-optimal alt)Optimal Mach/Alt
CASO High-Level Approach
Radar Tracks
Aircraft Fuel Burn Model
Lissys PianoXor
EurocontrolBADA 3.11
WeightEstimation
As-Flown Fuel Burn
Improved Fuel Burn
(from changed speed/alt)
CASO Benefits
Baseline (As-Flown) Trajectory
Weather CorrectionWind/Temp
Speed/Altitude
Optimizer
Modified Trajectory(Speed/Altitude)
Altitude Optimization
Joint Altitude and Speed Optimization
More Efficient
Less Efficient
Data from 2012 (18 days)
Mainline 3
Relative Speed Efficiency
More Efficient
Less Efficient
Data from 2012 (18 days)
Mainline 3
Relative Speed Efficiency
More Efficient
Less Efficient
Data from 2015 (2 days)PianoX Model
Mainline 3
Prototype Electronic Flight Bag Decision Support Tool
Step 1K Current Wt 320000 lbs ETA 06:02:30 ETE
Mod ETA 06:03:45 ETEFOD 10000 lbs
CurrentMach
0.810Change 1.25 mins
Mod FOD 10500 lbs
Cost Index
42.3 Init Climb In 01:03:20FOD Change +500 lbs
Mach Commanded. Highlighted Magenta
Calculated Cost Index from commanded Mach
Flight Plan VSDCASO Settings
Delayed Deceleration Approach (DDA) Concept
• Keep aircraft “clean” for longer on approach when appropriate without impacting terminal area entry or final approach stabilization criteria
– Between thesespeed gates, opportunity for encouraging moreefficient approachspeed profiles
Distance to touchdown
Airs
pe
ed
Typical
Conventional
Terminal area
entry speed
Final approach
speed
Sample flap 1
Sample flap 2
Runway
Delayed Decel.
=> Low Power/
Low Drag
“Clean” configuration
“Dirty”configuration
DDA Fuel Burn Reduction Potential
n = 61 flights on a 3
vertical profile
Fu
el b
urn
(lb
s)
Distance to touchdown (nm)
Distance to touchdown (nm)
Air
sp
ee
d (
kts
)P
ow
er
(%N
1)
0
0
0
0Distance to touchdown (nm)
Distance to touchdown (nm)
Fla
p a
ng
le (
de
gs)
A320 performanceprofiles
n = 61 flights on a 3
vertical profile
Fu
el b
urn
(lb
s)
Distance to touchdown (nm)
Distance to touchdown (nm)
Air
sp
eed
(kts)
Po
wer (
%N
1)
0
0
0
0Distance to touchdown (nm)
Distance to touchdown (nm)
Fla
p a
ng
le (
deg
s)
European A320 Flight Data Recorder Analysis
(similar results for B757 & B777)
30-50% fuel burn reduction potential from DDAs, 10,000 ft to touchdown
• Lowest fuel burn flights (green profiles) associated with delayed deceleration
DDA Speed Profile Analysis:NYC Metroplex
• Earlier decelerations generally observed under IMC compared to VMC
• LGA under IMC has earliest decelerations
EWR
JFK
LGA
EWR█ <= 210KIAS█ <= 180KIAS
LGA█ <= 210KIAS█ <= 180KIAS
JFK█ <= 210KIAS█ <= 180KIAS
15 nm
1 3 5 7 9 11 13 150
20
40
60
80
100
Time Flown Below 180 kt (min)
Perc
en
tag
e o
f A
ll L
an
din
gs
LGA VMC n = 10,530
LGA IMC n = 1,600
JFK VMC n = 9,070
JFK IMC n = 1,048
EWR VMC n = 4,435
EWR IMC n = 775
“Large” arrivals from ZDCJAN – SEP 2011
“Large” arrivals from ZDC, 8 sample days
0
1
2
3
4
5
6
7
VMC IMC Weighted
DDA Airport Comparison
•Significant variability between airports & operating conditions
• In general, best performance from less constrained airports
•Worst performance from constrained metroplexairports
• Large difference between VMC and IMC for many airports
• In process of extending to more airports & updating with 2015 data
* Relatively small sample size
Tim
e F
low
n B
elo
w 1
80
kts
fo
r 5
0%
of
Flig
hts
(m
ins)
“Large” arrivals from ZDC, JAN – SEP 2011
* *
Outreach Meetings
1. Meeting with airlines and ATC to discuss results and operational implications– Airline flight planning, dispatch, and operations departments– Procedures used for flight planning with respect to efficiency (i.e.
cost index policy, altitude selection, cockpit and ground weather sources)
– Initial meetings• Delta• American • United
– Additional meetings being scheduled