Design of a Flight Planning System to Reduce Persistent Contrail Formation

Team: Jhonnattan Diaz David GauntlettHarris TanveerPo Cheng Yeh

Sponsors: Center for Air Transportation Systems Research (CATSR), Mr. Akshay BelleMetron Aviation, Dr. Terry Thompson

UV/Visible Sunlight

Infrared Radiation

Earth

(Non-persistent) ContrailPersistent Contrail

1

Agenda

• Context• Stakeholder Analysis• Problem, Need Statement, Mission

Requirements• Design Alternatives• Design of Experiment• Project Management• Questions

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3

Global Climate ChangeEnergy

Demand

Burning of Fossil

Fuels

Greenhouse Gas

Emissions

Global Temperature

Increase

Global Climate Change

Melting Ice Caps

Mean Sea Levels Rising Extreme Storms Droughts

Department of Ecology. State of Washingtonhttp://www.ecy.wa.gov/climatechange/whatis.htm

“Global Climate Change.” National Aeronautics and Space Administration. http://climate.nasa.gov/effects

Population Increase

4

U.S. CO2 Emissions• Increasing trend of CO2

emissions

• 1.7 billion metric tons CO2 from Transportation sector

• Air transportation:– 11 % of CO2 emissions

from transportation sources • 1.9 million metric tons CO2

from Air Transportationhttp://www.epa.gov/climatechange/ghgemissions/gases/co2.htmlhttp://epa.gov/climatechange/ghgemissions/global.html

Projected Passenger Increase

5

2010 2015 2020 2025 2030 20350.0

50.0

100.0

150.0

200.0

250.0

300.0

f(x) = 4.21153837664033 x − 8317.79509663502

Projected Passenger Increase

Year

Sche

dule

d Pa

ssen

ger T

raffi

c (M

illio

ns)

6

H2O

Air

Fuel

SOx

HC

Soot

H2O Aerosols

Contrails

NOx

CO2

CH4

O2

Jet A Fuel Combustion Process

Sridhar, Banavar & Chen, Neil. “Design of Aircraft Trajectories based on Trade-offs between Emission Sources.” 2011.

aCnH2n+2 + bO2 + 3.76bN2 → cH2O + dCO2 + 3.76bN2 + heat

Aircraft Engine

Chemical Reactions

Microphysical Processes

Climate ChangeRadiative Forcing

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The Issue• Studies suggest persistent contrails may have a three to four times

greater effect on the climate than carbon dioxide emissions.• Contrails inhibit the movement of incoming and outgoing radiation

Waitz, I., Townsend, J., Cutcher-Gershenfeld, J., Greitzer, E., and Kerrebrock, J. Report to the United States Congress:Aviation and the Environment, A National Vision, Framework for Goals and Recommended Actions. Partnership for Air Transportation Noise and Emissions Reduction, MIT, Cambridge, MA, 2004.

UV/Visible Sunlight

Infrared Radiation

Earth

8

The Issue

Gossling, Stefan, and Upham, Paul. Climate Change and Aviation- Issues, Challenges and Solutions. 2009.

-Contrails cause greater radiative forcing than CO2-Contrails create induced cirrus clouds-The understanding behind contrails and induced cirrus clouds is relatively low

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Contrail Types

Aerodynamic

Short Term

Formed by pressure of air moving over

the surface of aircraft

Exhaust

Long Term/Persistent

Formed by mixing of hot, humid exhaust

mixing with cold surrounding air

• Contrail duration varies with respect to wind conditions (wind shear) as well as temperature changes

• Contrail frequency varies with frequency of weather conditions

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Persistent Contrail Formation Conditions

• Schmidt-Appleman Criterion– Altitude: 29,000ft - 41,000ft – Temperature: below -40℃– Humidity: RHi > 100%

• Ice content/ice capacity (Similar to RHw)• RHi > 100% indicates Ice Super-Saturated Region (ISSR)

• Greater likelihood of persistency in colder months. Palikonda, Rabindra. “Contrail climatology over the USA from MODIS and AVHRR data.” 2002.

Contrail Mitigation Studies

• Technological Changes– Fuel Additives– Jet Engine Redesign– Jet Airframe Redesign

• Operational Changes– Flight Planning Changes: contrail avoidance flight

paths

Royal Commission on Environmental Pollution, “The Environmental Effects of Civil Aircraft in Flight,” London, UK, 2002. http://www.rcep.org.uk/avreport.htm.

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Contrail Avoidance Flight Path

Contrail Avoidance Flight Path

Tactical Maneuvering

Strategic Maneuvering

• Tactical Maneuvering– En-Route request to maneuver

around ISSR

• Strategic Maneuvering– Pre-flight plan filed with ATC with

built-in ISSR avoidance

• For this Project: Strategic Maneuvering– Reduces cognitive workload on

ATC– Does not change current flight

planning process

Flight Planning

http://www.faa.gov/air_traffic/publications/controller_staffing/media/cwp_2012.pdf

Airline Dispatcher Flight Service Stations

Proposed Flight Plan

Accepted/Rejected Flight Plan

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Agenda

• Context• Stakeholder Analysis• Problem, Need Statement, Mission

Requirements• Design Alternatives• Design of Experiment• Project Management• Questions

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Stakeholder Analysis

Who is affected if contrail avoidance flight planning is attempted?

What are their interests and goals?

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Stakeholder Desires Tensions

Federal Aviation

Administration

(FAA) – Air Traffic

Organization (ATO)

Safety NAS Efficiency

ATO regulations on airlines may increase operational costs

Airline

Management –

Airline Operations

Center (AOC) -

Dispatcher

Maximize profit Minimizing costs Safety

General Public Safety Minimize air transportation costs Minimize Environmental impact

Do not want climate change General public desires safe transportation at the lowest

costs. Airlines want to charge the general public higher

costs to make greater profits

ATC/ATC Union Protect interests of air traffic controllers

Pressure ATO for better working conditions and higher pay

Pilot/Pilots Union Protect interests of pilots Pressure airlines for better working conditions and higher pay

Other Regulatory

Agencies (DOE,

DOT, EPA)

Safety in their respective fields Regulations may increase costs

Congress Legislation promoting American

interests Regulations may increase costs

NOAA Provide weather information for

airline use

ICAO Create global cooperation to reduce aviation’s impact on climate change

 

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Stakeholder Interactions

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Ideal Solution/Win-Win

• Win-win would occur with an ideal solution that would:– Maintain ATO’s desired

level of safety– Reduce airline operational

costs– Reduce environmental

impact

ATO

Maintain level of safety

Reduce Fuel Consumption

Airlines

Low airfare and clean

environment

Public

Although out of the scope of this particular project, it should be noted there is also a need for education regarding the effects of contrails

Agenda

• Context• Stakeholder Analysis• Problem, Need Statement, Mission

Requirements• Design Alternatives• Design of Experiment• Project Management• Questions

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Problem Statement

• Contrails have a negative impact on the environment.

• Lack of system negotiating stakeholders’ needs in order to provide flight paths avoiding ISSR while accounting for tradeoffs between– fuel consumption– travel time– miles of contrails formed

Royal Commission on Environmental Pollution, “The Environmental Effects of Civil Aircraft in Flight,” London, UK, 2002. http://www.rcep.org.uk/avreport.htm.

1980 1990 2000 2010 2020 2030 2040 2050 206002468

10121416

7.063.5

9.4

14.8

Estimated Radiative Forcing by Con-trails

Contrail Neutral

Years

Radi

ative

For

cing

(m

W/m

^2)

Gap

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Contrail favorable weather conditions

# of jets

Miles of contrails Radiative Forcing

Contrail Neutral

Marquart et al., 2003: Future development of contrail cover, optical depth, and radiative forcing: Impacts of increasing air traffic and climate change.

% Contrail Coverage

IATA: “Reduce net CO2 emissions by 50% by 2050 compared to 2005.” IATA: “Global cap on our [CO2] emissions in 2020.”

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Need Statement• Need to provide FAA and AOC with a Decision Support System to

estimate– amount of fuel consumed

• CO2 emissions produced– miles of contrails formed– flight duration

• Need to analyze relationship between – amount of fuel consumed

• CO2 emissions produced– miles of contrails formed– flight duration– percentage of contrail avoidance attempted.

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Mission Requirements

• MR1: The system shall provide the ability by 2020 to reduce the radiative forcing due to contrails to the 2005 baseline of 7.06mW/m^2.

• MR2: The system shall provide the ability to maintain contrail neutrality after 2020 at the radiative forcing value of 7.06mW/m^2.

MR3: The system shall minimize CO2 emissions, miles of contrails formed, flight duration, fuel consumption.

MR4: The system shall maintain an equivalent level of safety standards for aircraft spacing.

Agenda

• Context• Stakeholder Analysis• Problem, Need Statement, Mission

Requirements• Design Alternatives• Design of Experiment• Project Management• Questions

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Design Alternatives

Design Alternatives

1. Contrail Avoidance Flight Path

1.1 Vertical Maneuvering

1.2 Horizontal Maneuvering

1.3 Combination Maneuvering

2. Airway Routes

3. Great Circle Distance

(GCD)

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Contrail Avoidance Methods

Z

XA B

RHi>100% Altitudes of Concern(29,000-41,000 ft.)

A

B

X

Y

A

B

X

Y Z RHi>100%

Horizontal Adjustment

Altitude Adjustment

Combination Adjustment

Red: Travel Through Contrail RegionsBlue: Contrail Avoidance

Value Hierarchy

Creating a Flight Plan

Aircraft SafetyAmount of

Fuel Consumed

Flight Duration

Total Miles of Contrails Formed

*Note: CO2 emissions are a linear factor of amount of fuel consumed27

Assume safety levels will be maintained

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Sample Use CaseAnticipated Users: --Airlines--Air Traffic Control

User System NOAA

Input Origin/Destination

Input AircraftRequest Weather Data

Send Weather Data

Contrail Avoidance Flight Path

Great Circle Distance Flight Path

Airway Routes

Fuel Consumption per path

Contrails Formed per path

Flight Duration per Path

Agenda

• Context• Stakeholder Analysis• Problem, Need Statement, Mission

Requirements• Design Alternatives• Design of Experiment• Project Management• Questions

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Design of Experiment• Control:

– Great Circle Distance (GCD) 0% Avoidance

• Independent Variables:– Flight Plans

• Airway Flight plan Actually filed plan• Contrail Avoidance Flight plan

– Altitude Adjustment– Horizontal Adjustment– Combination Adjustment

• Dependent Variables:– Fuel Consumption– Miles flown through contrail regions– Flight Duration– Carbon Dioxide Emissions

Design of Experiment

• Procedure– Each aircraft (≈ 22,000) will be flown with each of

the alternative flight routes– CO2 emissions and miles of contrails formed will

be summed for all flights for each alternative flight route to view total effect on NAS

– Tradeoff analysis will be completed between each of the dependent variables• Currently in the process of devising tradeoff analysis

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Scope and Assumptions

Scope

1 Day of Flights (24 hours)

Continental United States

US Domestic Passenger Jet aircrafts

Utilizing NOAA Weather Data (RAP)

Experimental Assumptions

Contrails will only form en-route

Constant en-route airspeed

Uniform Aviation Fuel – (Jet A)

ISSR will always produce contrail (binary regions)

Contrail albedo and optical density will not be considered

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System Requirements The system shall accept flight path data as an input. The system shall accept NOAA .grib2 weather data as an input.

The system shall identify the location and the dimension of the ISSR. The system shall perform vertical avoidance, horizontal avoidance,

and combination avoidance. The system shall output contrail distance formed, amount of

fuel used, CO2 emitted, and total flight time. The system shall be able to model contrail avoidance paths. The system shall be able to model airway routes. The system shall be able to model the great circle distance.

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High Level Simulation I/O

RAP Data From NOAA

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• Matrix obtained from .grib2 files

• .grib2 files obtained through publicly available FTP from NOAA

• ISSR Data

• Graphical representation of RHw weather data

• Temperature data is in similar format

• Lambert Projections

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Contrail Avoidance System

• Uses predicted weather data to avoid areas with a high chance to yield persistent contrails.

• The system shall be able to determine which weather cells must be avoided to reduce contrail formation.

• Inputs– Flight Object– Weather Object

• Outputs– Fuel Consumption– Miles Contrail Formed– Flight Time

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Physical Processes Modeled

• Velocity• Thrust • Drag• Fuel Consumption • CO2 Emissions• RHi for persistent contrail formation

Anticipated Results

• More contrail avoidance maneuvers will cause more fuel burn

• Each alternative will be weighed on value hierarchy weights

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Anticipated Recommendations

• Recommend flight plan with optimum tradeoff between– Miles of contrails produced– Amount of fuel burned– Amount of CO2 produced– Flight duration

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Project Management

Work Breakdown Structure• Project Management• Research• Problem Statement• Needs Statement• Context Analysis• Stakeholder Analysis• System Alternatives• Requirements• CONOPS• System Modeling and Design• Simulation• Results Analysis• Deliverable Preparation• Poster• Youtube Video• Conference Preparation

• 16 major topics decomposed into subtasks– 131 total tasks

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Scheduling

• Critical Path– Need Statement– Stakeholder Analysis– System Alternatives– Simulation– Results Analysis

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Budgeting• Cost/engineer

– Baseline cost: $45/hour/engineer– GMU overhead: $2.13 multiplier– Total cost/engineer: $95.74/hour/engineer

• Worst Case Plan:– Hours: 1,457– Cost: $139,500

• Best Case Plan:– Hours: 730– Cost: $69,750

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0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38$0.00

$20,000.00

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$160,000.00

Earned Value Management

AC

EV

Best Case PV

Worst Case PV

Weeks

Dolla

rs

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0 2 4 6 8 10 120.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

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5.00 CPI & SPI

CPISPIControl

Weeks

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Next Phase Plan

• Continue developing contrail avoidance algorithm• Begin Programming Simulation: 11/25/2013• Value Hierarchy Weights• Consider wind optimal routes• Working in Partial Contrail Avoidance• Devise tradeoff analysis• Analyze NOAA Rapid Refresh Data for patterns

and trends

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Risks

• High Risk, High Impact:– Contrail avoidance and flight path algorithms

complication may exceed comprehension• Mitigation: Request expert help

• Medium Risk, High Impact:– Simulation coding not being done on time

• Mitigation: more hours

• Medium Risk, Medium Impact:– Deliverables not completed on time

• Mitigation: more hours

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Questions?