4 cold fuel management

8/21/2019 4 Cold Fuel Management

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COCESNA March 2005

• Introduction/Opportunities

• FAA Guidance Material

• Operational Considerations

–

En Route Alternate Airports – Cold Fuel Management

– Navigation

– Communications

– Cosmic Radiation – Additional Considerations

• Route Development Status

•Summary



COCESNA March 2005

Why is a Cold Fuel ManagementProcess Needed?

Fuel freeze maybecome an issue when

Temperatures drop

below -65 deg. C

-45 to -49 C

-50 to -55 C

-55 to -59 C

-60 to -64 C

<-65 C



COCESNA March 2005

Cold Fuel ManagementA Planned Operational Capabil i ty

• FAA Guidance Material

• Fuel Properties

• Airplane Operation

• Fuel Temperature Prediction Program

• Freeze Point Measurement



COCESNA March 2005

FAA Guidance MaterialFuel Freeze Strategy and Monitor ing

• Fuel freeze analysis program may be used in lieuof standard minimum fuel freeze temperatures

• Monitoring program must be acceptable to theFAA

• Maintenance, dispatch, and flight crew proceduresmust be in place



COCESNA March 2005

FAA Guidance MaterialFuel Freeze Strategy and Monito ring

• The operator may wish to develop a fuel freezeanalysis program in lieu of using the standardminimum fuel freeze temperatures for specifictypes of fuel used.

• In such cases, the operator’s fuel freeze analysisand monitoring program for the airplane fuel loadmust be submitted and acceptable to the FAA.

• The operator should have procedures established

that require coordination between maintenance,dispatch, and assigned flightcrew of thedetermined fuel freeze temperature of the actualfuel load on board the airplane.



COCESNA March 2005

Fuel Properties

• Fuel freezing point is the temperature atwhich wax crystals, formed in the fuelas it is cooled, completely disappear

when warmed.

– Wax crystals can restrict the flow of fuelthrough filter screens to the engines


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Airplane Operation

• Airplane will provide advisory message “FUEL TEMPLOW” 3o C above fuel freeze point

• Default value for annunciation is -37o C (Freeze point forJet A is –400C)

• Actual freeze point may be entered into the 777 FMC(PERF INIT page)



• Fly around the cold air,

• **Descend to a lower, warmeraltitude, or

• Increase aircraft speed to increaseaerodynamic warming

**(to be revised)

Flight Crew Action Required for

Note: In extreme cases it may be necessary to do all three

FUEL TEMP LOW



Fuel Freeze Point Determination

• Measure freeze point of fuel actually loaded aboardaircraft

• Several airlines are using local Jet Fuel Quality Analyzers

• On average the delivered freezing point of Jet A has been4oC better than the specification maximum



Fuel Freeze Point Measurement Survey

The Phase Technology Program

Delivered fuel freezing point (

C), Jet A

Avg. Temp Temp range

Dallas-Ft. Worth -43 -40.2 to -47.0 New York -45 -41.5 to -47.5

Los Angeles -50 -46.8 to -58.2 Miami -47 -41.1 to -52.5 Chicago -43 -41.5 to -44.7 San Francisco -45 -44.0 to -56.1

Atlanta -43 -41.5 to -46.6



Fuel Temperature Prediction

• Boeing has developed a fuel temperatureprediction program (FTPP) for use on the 747

• Program can interface with airlines flight planningsystem

• The FTPP has not been calibrated with 747 flighttest data



FTPP Allows Airlines to Address ColdFuel in the Dispatch Process

Fuel Temperature PredictionProgram calculates fueltemperature based on flight

plan data

MAS 777 Flight Plan - m as6203kg

-40

-35

-30

-25

-20

-15

-10

200 300 400 500 600 700 800 900 1000 1100

Flight Time - Minutes

T e m p e r a t u r e - D e g r e e s C

TAT - C

Fuel T - C

PLAN 6203 MAS5405 KPAE TO WMKK 777C M84/F IFR 04 /25/01

NONSTOP COMPUTED 1737Z FOR ETD 1900Z PROGS 2512ADF WB173 KGS

FTPP - MAS V1.0 04/25/2001 AT 11:24:35



FTPP Output Plot

MAS 777 Flight Plan - mas6203kg

-70

-60

-50

-40

-30

-20

-10

0

10

20

0 200 400 600 800 1000 1200

Flight Time - Minutes

T e m p e r a t u r e - D e g r e e s C

SAT - C

TAT - C

Fuel T - C

Act Fuel T - C

PLAN 6203 MAS5405 KPAE TO WMKK 777C M84/F IFR 04/25/01

NONSTOP COMPUTED 1737Z FOR ETD 1900Z PROGS 2512ADF WB173 KGS

FTPP - MAS V1.0 04/25/2001 AT 11:24:35



Fuel Freeze Dispatch Process



Example Dispatch Process

• Prepare Flight Plan usingforecast winds andtemperatures.

• Predict fuel temperatures(Boeing FTPP) usingspecification fuel freeze pointand historical fueltemperature.

• Fuel Temp. > 3 deg. C. abovefreeze point, proceed with

current flight planning.

• If fuel temp is < 3 deg. Cabove freeze point, go to step2.

Cold Fuel Management Process Step 1




• Prepare new Flight Plan

• Predict fuel temperatures(Boeing FTPP) using historicalmeasured fuel freeze point and

historical fuel temp.

• Fuel Temp. > 3 deg. C. abovefreeze point, proceed withflight planning and notifyfuelers of special fuelingprocedures to validate

historical data.

• If fuel temp is < 3 deg. C abovefreeze point, go to step 3.

Cold Fuel Management Process Step 2




Cold Fuel Management Process Step 3(When required)

• Prepare New Flight Plan with:

– New Routing; or

– New Altitude Profile; or

– Higher Mach

• Repeat Steps 1 & 2 as

required

New Routing; or

New Altitude

Profile; or

Higher Mach



COCESNA March 2005

Special Fueling Procedure

Fuel Freeze Point Measurement(When required)

• Transfer fuel from wing tanksto center tank or use fuelcommingling charts in

cooperation with dispatch.

• Sample fuel uploaded toairplane.

• Analyze fuel samples todetermine actual freeze pointof fuel for each sample.



COCESNA March 2005

Special Fueling Process

• Determine highest

measured fuel freeze pointfor the uplifted fuel

• Forward fuel freezetemperature:

– Flight Planning

– Flight Crew

– Fuel Manifest, or

– Log Book

Cold Fuel Management Process Step 2.A(When required)

Flight XYZ

Truck 1 -44.8

Truck 2 -44.6

Truck 3 -44.9Truck 4 -44.5

Truck 5 -44.7



COCESNA March 2005

SummaryCold Fuel Management

• Fuel freeze strategy and monitoring is required byFAA

• Cold Fuel Management Process allows airlines toaddress fuel freeze issues during the dispatchprocess to prevent fueling delays

• Fuel freeze point measurement provides 3 to 18 deg.C additional margin

4 cold fuel management

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