performance retention and fuel saving a330 a340

Upload: lbrito01

Post on 24-Feb-2018




14 download


  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Airbus Flight OperationsJune 2015

    Getting to grips with

    performance retention

    and fuel saving

    A330/A340 Family

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340









    Industry Issues


    Fuel saving opportunitiesp.017

    Summary & Conclusions





  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Dear Operator,

    In spite of some recent stability in fuel prices this commodity continues to

    represent the single greatest cost for almost every commercial aircraft operator.

    The obvious economic issue is now being complemented by environmental

    issues. These are driving airlines to increasingly invest resources to optimise

    fuel and operational costs. The process is often complex but the mantra of

    "every kilo counts" can be increasingly heard.

    In support of this optimisation process, there is a multitude of information

    published by both the Aircraft Manufacturers and Industry bodies describing

    the mechanisms by which fuel can be economized.

    This document represents the latest contribution from Airbus. The document

    was designed to provide a holistic view of the subject from the manufacturers

    perspective. In producing the document we brought together specialists from

    the fields of aircraft performance, aerodynamics and engine and airframe

    engineering, and integrated their inputs that were born out of their wide

    experience with in-service aircraft. The aim was and is to share best practices

    by providing you with a guide to selected initiatives that can reduce both the fuel

    bill and the operating cost of your A330/A340 Family aircraft. You will find brief

    discussions of the various initiatives that highlight both their pros and cons.

    This is an update of the document published in september 2011, which

    includes a wide range of refinements.

    We wish to express our thanks to those within and outside Airbus who have

    contributed to this brochure.

    Should you need further information you will find contact details adjacent

    to each topic covered by this brochure.

    Best regards,

    Dominique DESCHAMPS

    Vice President Flight Operations

    and Training Support

    Customer Services

    Sabine KLAUKE

    Vice President

    A330/A340 Family Programme

    Customer Services

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    #1 ScopeThis document discusses the basicprinciples of fuel efficiency for in-serviceaircraft. It highlights measures thatcan reduce the fuel consumption ofAirbus A330/A340 family of aircraft.

    The documents objective is to con-

    tribute to the general awareness of

    fuel efficiency throughout the airline

    and beyond. It is a starting point and not

    a definitive guide to what an operator

    must do to minimize fuel consumption

    or, more precisely, minimize operational

    costs. It provides a basis for study.

    Implementation of initiatives described

    in this document should be evaluated

    in the context of the operators specific

    operation and in collaboration with all


    The document has been written prin-cipally from the perspective of the

    aircraft, its operation, maintenance

    and servicing. However, where

    appropriate, mention is made of

    other influencing factors, such as

    scheduling or passenger service level.

    Environmental issues are becoming

    increasingly important and these too

    have been outlined. References and

    points of contact within Airbus are pro-

    vided throughout for those wishing to

    explore any item more fully.

    003Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Introduction#2Elementary physics tell us that for an aircraft to fly it must

    generate lift to overcome its weight. Generating lift produces

    drag, (as does the movement of the airframe through the

    air). The engines generate the thrust necessary to overcome

    the drag. The greater the thrust required the more fuel is

    burnt. This document discusses methods of minimizing

    that fuel burn.

    Airbus Flight Operations04

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Like most commodities, the price of

    fuel increases with time. However,

    fuel prices can be volatile, tending to

    be highly influenced by crises of all

    kinds: economic, political and natural.

    In addition, the rate at which fuel price

    grows is greater than the rate at which

    the price of other goods and services on

    which airlines rely on to operate grows.

    Figure 2-1:

    Elementary forceson an airframe





    Airbus Flight Operations 005

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Figure 2-2 illustrates the long-term

    increasing trend of jet fuel price withits short-term high volatility. As an

    example, 2011 price has been influ-

    enced by Northern Africa / Middle East

    political instability and high demand in

    China and other developing countries.

    More recently the discovery of further

    reserves of fossil fuel in several regions

    of the world has had a stabalising effect

    on prices.

    Speculation also plays a key role in oil

    price variations. It is estimated that in

    2010 the quantity of crude oil traded

    in exchange markets represented

    20 times more than the physical world

    consumption it has become the most

    traded commodity in the world.

    Fuel hedging (agreeing a fixed price

    for a specified amount of fuel that will

    be purchased over a specified period)

    offers airlines the opportunity to

    maintain a degree of control over fuel

    price variations. Deciding when and

    how much fuel to "hedge" is typicallythe responsibility of the airlines fuel

    purchasing manager.

    The cost of fuel is the major contrib-

    utor to Cash Operating Cost (COC).

    Cash Operating Cost is the aircraft

    direct operating costs less the costs of

    insurance and ownership of the aircraft

    (e.g. finance, depreciation or lease fees)

    it may be thought of as the cost of flying.

    Figure 2-2:

    Monthly Jet Fuel Price Trend(Source: EIA, U.S. Gulf Coast

    Kerosene-Type Jet Fuel Spot Price)

    2001200220032004200520062007200820092010201120122013 2015(first 3 months)


















    per USGallon

    US$ perBarrel

    Airbus Flight Operations06

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    An aircraft of the A330/A340 Family

    will typically consume between 18 and45 tons of fuel (approximately 6 000 to

    15 000 US Gallons) per flight. Actual fuel

    consumption depends on a multitude

    of parameters including aircraft type,

    distance flown and payload. Many of

    these aspects are discussed in this

    document. Figure 2-5 below offers an

    insight in to the yearly fuel bill for A330/

    A340 aircraft in airline service on typical

    missions (described as Short, Medium

    and Long) and how it varies with fuel

    price. The chart serves to illustrate that

    even fuel efficiency measures that offer

    only tiny savings in percentage terms

    can still generate worthwhile cash


    Figure 2-3:Cost of Operation Breakdown 2004(Fuel at US $1.15 per US Gallon)

    Figure 2-4:

    Cost of Operation Breakdown 2013(Fuel at US $2.92 per US Gallon)

    Direct Operating CostBreakdown - 2004

    Direct Operating CostBreakdown - 2013

    Crew 18%24%






    Crew 14%







    007Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Fuel efficiency is not new. However,

    fuels increasing price and contribution

    to the operating cost pie means that

    initiatives that might previously have

    been assessed as marginal may merit

    re-examination as the cost breakdown

    evolves. It should also be borne in

    mind that implementing fuel efficiency

    measures often has a cost. Furthermore,

    the full extent of these costs may not

    immediately be visible. To minimize

    the risk of unwelcome surprises it is

    essential that possible initiatives be

    reviewed with all functions within the

    Airlines organization.

    Much has been written to support

    Airlines in wishing to minimize their

    fuel and operational costs. Industry

    bodies and manufacturers have both

    made contributions. Airbus principle

    contribution in this field has been thedevelopment of a number of documents

    under the generic title of "Getting to

    Grips". These documents provide an

    in-depth insight into topics such as

    cost index, aerodynamic deterioration

    and fuel economy (ref. table beside).

    This document is a compilation of best

    practices, derived from the in-service

    experience of Airbus and its Customers.

    The init iatives it describes cover

    operational, maintenance and servicing

    aspects that, in some cases may have

    implications for the service and comfort

    levels the airline offers its customers.

    The document provides, for a broad

    range of aircraft standards and a wide

    variety of operations, concise advice on

    operation and maintenance practices

    that have been shown to limit in-service

    performance degradation and facilitate

    efficient operations.


    10 000 000

    20 000 000

    30 000 000

    40 000 000

    50 000 000

    60 000 000

    70 000 000

    80 000 000

    Fuel Price (US$ per US Gallon)

    AnnualFuel Cost


    1.00 2.00 3.00 4.00 5.00

    Figure 2-5:Annual fuel consumptionper aircraft

    Table 2-2:

    Adjustment factors forcalculation of specific fuel costs

    Table 2-1:Reference mission profilesfor this document

    Calculating costs for a typenot covered in the costcharts:_Example: (refering to Chart 2-5)to estimate the Annual average fuel

    cost for an A330-300 with a "Short"

    average annual mission profile (asdefined in table 2-1 under A330-200

    / Short) take the annual fuel cost for

    a A330-200 "Short" mission andmultiply by the adjustment factor -106% in this case.



    to A330-300



    to A340-200



    to A340-500

    Long107% 96%



    Short 106%







    AverageSector Length (nm)

    3 520 3 740 4 200

    Annual Cycles 650 640 570

    Average Trip Time (hours) 7.6 8.1 9.1


    AverageSector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    Average Trip Time (hours) 5.6 5.2


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160

    Average Trip Time (hours) 3.4

    Airbus Flight Operations08

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Important Note:_None of the information contained in

    the Getting to Grips publications is

    intended to replace procedures or

    recommendations contained inthe Flight Crew Operating Manual(FCOM). The brochures havingdirect influence on fuel economyhighlight the areas where mainte-

    nance, operations and flight crewscan contribute significantly to fuelsavings.

    All these documents are available in Adobe PDF format on the Airbus World website: (please note that access to this site is restricted. It is managed by airlines IT administrator).Table 2-3:

    Other "Getting to Gripswith" brochures

    Getting to Grips brochures

    The following titles are available and cover all Airbus types:

    Point of contact:

    [email protected]

    Direct influence on Fuel Economy Issue N Issue Date Available in

    Getting to Grips with A330/A340 Family Performance

    Retention and Fuel Efficiency2 Apr-15 English

    Getting to Grips with A320 Family Performance

    Retention and Fuel savings3 Dec-14 English

    Getting to grips with Fuel Economy 4 Oct-04 English

    Getting hands-on experience with aerodynamic deterioration 2 Oct-01 English

    Indirect influence on Fuel Economy

    Getting to grips with the Cost Index 2 May-98 English

    Getting to grips with Aircraft Performance 1 Jan-02 English, Chinese, Russian

    Getting to grips with Aircraft Performance Monitoring 1 Jan-03 English

    Getting to grips with Weight and Balance 1 Feb-04 English

    Getting to grips with MMEL/MEL 1 Jul-05 English, Chinese, Russian

    Getting to grips with RNP AR 2 Feb-09 English

    Other titles

    Getting to grips with ETOPS Volume 1: Certification and Approval 1 Dec-14 English

    Getting to grips with ETOPS Volume 2: The Flight Operations view 1 Dec-14 English

    Getting to grips with Cold Weather Operations 1 Jan-00 English, Chinese

    Getting to grips with surveillance 1 May-09 English

    Getting to grips with Cat II / Cat III operations 3 Oct-01 English

    Getting to grips with FANS 4 May-14 English, Chinese

    Getting to grips with Aircraft noise 1 Dec-03 English

    Getting to grips with Datalink 1 Apr-04 English, Chinese

    Getting to grips with Fatigue and Alertness Management 3 Apr-04 English

    Getting to grips with Modern Navigation 5 Jun-04 English, Chinese

    Getting to grips with Cabin Safety 3 Dec-11 English, Chinese

    Getting to grips with Approach and Landing Accidents Reduction 1 Oct-00 English, Chinese, Russian

    009Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Optimizing fuel consumption is an issue

    for many groups in commercial avia-

    tion. Motivation to deal with the subject

    comes not only from the desire to min-

    imize fuel expenditure, but to increase

    overall efficiency and also from the wish

    to address environmental concerns. In

    simplistic terms, reducing fuel burn isthe best way to reduce emissions, and

    hence the environmental impact, and

    fuel expenditure.

    The market expects aircraft manufactur-

    ers such as Airbus, in cooperation with

    their suppliers, to design and deliver the

    most economically efficient aircraft with

    the best environmental performance

    possible. Airbus is indeed committed to

    improving the fuel burn and emissions

    performance of its aircraft through the

    implementation of new technologies

    once they reach maturity for airline use

    and through research programmes in

    emerging technologies. The launch of

    the A320 Family neo or New Engine

    Option is an excellent example of how

    this commitment drives aircraft perfor-

    mance development.

    The key role for the operator is to

    keep the aircraft in good condition and

    ensure that they are operated efficiently.

    Infrastructure providers and managers

    such as aviation authorities, air-traffic

    control (ATC), airport authorities and air

    navigation service providers (ANSPs)

    can all contribute by providing airlines

    with the means to use their aircraft in

    the most efficient way possible.

    Optimum operational conditions can

    be compromised by Air Traffic Control(ATC) requirements. For example,

    aircraft kept waiting on the taxiway,

    restricted to non-optimum flight altitude



    Airbus Flight Operations10

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    by an ATC requirement or simply not

    permitted to fly the most direct route do

    not optimize fuel consumption.

    Such constraints will always be a feature

    of commercial aircraft operations to a

    certain extent. However, ATC reformand modernization continues, driven

    principally by increasing air traffic.

    Airbus also contributed to the Atlantic

    Interoperability Initiative to Reduce

    Emissions (AIRE) programme launched

    by EC and FAA in 2007 to demonstrate

    and promote short term improvements

    through more efficient ATM proce-

    dures based on current technology.

    Activities include several initiatives that

    have been developed to allow the use

    of fuel efficient continuous descent

    approaches at various airports.

    Ai rbus and industry bodies such

    as the A4A and IATA offer support

    services such as training courses and

    consulting. For example, Airbus Fuel

    and Flight Efficiency Consulting Service

    (See section seeks to identify

    and implement fuel savings through a

    combination of route improvements,infrastructure enhancements, reduced

    flight times and operational efficiency


    Furthermore, Operators may find it ben-

    eficial to review their operation require-

    ments and capabilities with their local

    ATC authorities to both raise mutual

    awareness and identify opportunities

    for route and schedule optimization.

    Focus on Airbus ProSky:_

    Airbus ProSky, an Airbus subsidiary, is committed to shaping the future of

    global Air Traffic Management (ATM), working side-by-side with ANSPs,aircraft operators and airport authorities to build a truly collaborative system

    with greater capacity, better performance and environmental sustaina-bility for all stakeholders. More precisely, Airbus ProSky is comprised of:

    Recognised ATM experts providing a comprehensive set of ATMservices for a performance-based, benefit-driven approach to ATMmodernization and gate-to-gate optimization, which is addressedthrough operational, technical, financial and human issues.

    Metron Aviation offering an advanced, global Air Traffic FlowManagement (ATFM) solution, called Metron Harmony, for ANSPs,aircraft operators and airport authorities to improve efficiency,increase predictability and enhance safety for the entire air trafficsystem.

    Specialists in Performance Based Navigation technics, providingPerformance-Based Navigation techniques to enable aircraft tofly precisely along a pre-defined route by leveraging GPS-basedonboard navigation systems to reduce aircraft separation andoptimize arrival and departure procedures.

    ATRiCS offering a Surface Management (SMAN) system thatintelligently controls airfield ground lights, achieving a level ofautomated guidance and control, proven to reduce controllerworkload and improve common situational awareness for pilots.

    Airbus ProSky is not only dedicated to supporting overal l globalAir Traffic Management modernization and harmonization, but alsosupporting EUROCONTROLs Single European Sky ATM Research(SESAR) and the Federal Aviation Administrations (FAA) Next Generation

    Air Transportation System (NextGen). SESAR and NextGen are twomajor development programmes for ATM launched in 2008. They aimby 2020 to reduce the environmental impact by 10% per flight, triplethe air traffic capacity, halve ATM costs and improve safety. AirbusUpgrade Services team (e-Catalogue can be found on the Airbus Worldwebsite) can provide all the necessary information regarding theembodiment of the service bulletins that can bring aircraft up to thestandards required for operations in the evolving SESAR and NextGenenvironments.


    IATA Guidance Material and Best

    Practices for Fuel and

    Environmental Management,

    3rdEdition May 2008.





    Airbus ProSky:

    Metron Aviation:



    Airbus points of contact:

    Upgrade Services:

    [email protected]

    Airbus Fuel and Flight Efficiency

    Consulting Services:

    [email protected]

    011Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Like many human activities, aviation

    and the air transport industry have an

    impact on the earths environment.

    The consequences of aircraft operations

    that are typically of public concern areengine emissions and aircraft noise.

    A further source of concern is the

    use, handling and disposal of certain

    materials that are encountered when

    maintaining aircraft (e.g. asbestos,

    chromates). Like aircraft noise, these

    aspects are not directly related to

    fuel efficiency but they are mentioned

    in this section to give a more com-

    plete picture of environmental issues

    (the document and web sites refer-

    enced below offer further reading on

    these aspects).

    When any fossil fuel (gas, coal, oil)is burnt in air, the chemical reaction

    that takes place produces heat (that

    an engine will convert into power) and

    gaseous bi-products. These gases are

    principally water vapour (H2O), carbon

    dioxide (CO2) and various other oxides

    such as (NOx). While these gases are

    naturally present in the earths atmos-

    phere, it is the additional man-made

    contribution that is widely believed to

    have detrimental effects on the envi-ronment; known as Greenhouse Gases

    (GHG), they are indicated as being the

    cause of Global Warming.



    Focus on CO2:_Carbon Dioxide (CO2) is a

    product of the chemical re-action that takes place whenburning any mixture of air anda petroleum-based product.Jet turbine engines producearound 3.1 kg of CO2for everykg of jet fuel burnt. At this pointit is worth noting that today,aviation as a whole, accountsfor only 2% of man-made CO2emissions (this is forecast toreach 3% by 2050).

    Focus on NOx:_NOX, or nitrogen oxides, areanother bi-product of burningfuel in an engine. Like CO2,they are believed to have a det-rimental effect on the worldsenvironment.In recognition of this, the airports

    of some nations adjust theirlanding charges according to the

    amount of NOXproduced by theaircraft (as defined in the certifi-cation datasheet). Airbus aircraft

    have always been equipped with

    state-of-the-art engines offering

    among the lowest NOXlevels intheir class.








    Energy Industry Roadtraffic

    Aviation Othermeans oftransport



    Variation between studies

    Figure 3-1:

    Human activities contribution toCO2emissions. Sources: IPCC,

    UNFCCC, IEA and DLR.

    Airbus Flight Operations12

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    The Focus on CO2 text box with

    Figure 3-1 illustrates that the aviation

    industrys consumption of fossil fuel

    and the consequent production of CO2

    is relatively low. Notwithstanding thisfact, aviation has been in the spotlight

    and increasingly targeted by media

    and public opinion in general. There

    are many references to aviation having

    a greater effect than other industries

    because of the higher altitude at which

    the emissions are released.

    Even though the most prevalent green-

    house gas, CO2, spreads quickly in the

    atmosphere, it does not matter whereor at what altitude it is emitted (sea level

    or 39 000 ft), the impact is the same.

    However other emissions such as NOx

    are believed to have a higher effect at

    higher altitudes.


    Getting to grips with Aircraft noise Issue 1, December 03







    visit the website of the

    European Commission:



    Monitoring, reporting and

    verification plan see:

    Airbus OIT SE 999.0071/09

    Focus on the EU-ETS:_

    The European Union (EU), in its Directive (2003/87) on Greenhouse Gas(GHG) Emissions Trading Schemes defines a "cap and trade" system for

    CO2 emissions. The chargeable proportion of emissions is determinedby an assessment of fuel efficiency. For the period 2013-2016 only

    emissions from flights within the EEA fall under the EU ETS. Exemptionsfor operators with low emissions have also been introduced. Note thatthe International Civil Aviation Organization (ICAO) is currently develop-ing a global market-based mechanism addressing international aviationemissions with a target of application by 2020.

    013Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Until recently aircraft fuel consisted only

    of refined hydrocarbons derived from

    conventional fossil sources such as

    crude oil. However, fuel can be refined

    from other materials including naturalgas, coal and biomass.

    Jet fuels produced from alternative sources

    produce the same amount of CO2when

    they are burnt as their "traditional" equiva-

    lents. However, the production of sus-

    tainable biofuels (those produced from

    sustainable biomass sources, see

    next paragraph) contributes to CO2

    reduction. Figures 3-2 and 3-3 illus-

    trate the emissions produced during the"lifecycle" of fossil fuels and biofuels.

    All plants absorb CO2as they grow.

    The CO2absorbed by plants used to

    produce biofuel is roughly equivalent to

    the amount produced when the fuel is

    burnt as such sustainable biofuel is

    close to CO2neutral.

    Sustainable biofuels are those cre-

    ated from biomass that does not

    compete with food production, use of

    fresh water, causes deforestation orreduces biodiversity. A variety of plants

    if managed correctly can be grown sus-

    tainably e.g. sugar cane, corn, wheat,

    jaropha, camelina, halophytes, algae.

    As mentioned, fuel can also be pro-

    duced from natural gas and coal (both

    "fossil" fuels). A coal to fuel process

    that does not include CO2sequestra-

    tion (capture), results in the release of

    more CO2than the crude oil to fuel

    refining process. The natural gas to fuel

    process produces CO2at comparable

    levels to those from the crude oil refining

    process. However, burning natural gas

    derived fuels produces less particulate

    matter. This leads to improved local air

    quality at airports.

    Airbus strategy for the short to mid-

    term is to focus on alternative fuel

    sources that are drop-in and derived

    from sustainable sources. Drop-in fuels

    meet the already established require-ments for jet fuels. They are currently

    certified for use when mixed with fuel

    derived from traditional sources. This

    strategy allows continued use of existing

    aircraft and airport supply infrastructure.

    With the initial certification challenges

    met the use of aviation biofuel can now

    grow. The technologies for the pro-

    duction of fuels from biofuel sources

    are understood. The challenges todayare the sustainable commercialisation

    of these fuels and the need to con-

    tinue research on suitable feedstocks

    and to find the best solutions for local

    value chains around the world. Airbus

    is therefore partnering with airlines to

    connect farmers, refiners and end users

    (airlines) to form sustainable biofuel

    "value chains" in regions across the

    world working with the Round table on

    Sustainable Biofuels (RSB) to guarantee

    their sustainability-economic, social and

    environmental. Six such partnerships

    had been established at the time of

    writing: Australia (Virgin Australia), Brazil

    (TAM), Middle East (Qatar), Romania

    (TAROM), Spain (Iberia), China (China

    Southern) and research partnerships

    are in place in Malaysia, Canada and




    Airbus Flight Operations14

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Figure 3-2:

    Lifecycle emissions from fossil fuels

    At each stage in the distribution chain, CO2is emitted through energy use by extraction,transport, etc. (Source: Beginners Guide

    to Aviation Biofuels,

    Figure 3-3:

    Lifecycle emissions from sustainable biofuels

    CO2emitted will be reabsorbed as the nextgeneration of feedstock is grown. (Source:Beginners Guide to Aviation Bioduels,





    Airbus points of contact:

    Sustainable fuel value chain development:[email protected]

    Certification of sustainable jet fuel sources:[email protected]

    Fuel system engineering:[email protected]

    Distributionat airports

    Distributionat airports










    015Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    4.1 Introduction ..................... 17

    4.2 Operational Initiatives ..... 19

    4.2.1 Aircraft operations ........... 19

    4.2.2 Cost index ........................ 19

    4.2.3 Fuel economy ................... 20 Cruise speed...................... 20 Flight Level ......................... 22 Flight Plan accuracy ........... 23 Aircraft performancedegradation........................ 23 Fuel reserves...................... 24 Airbus OperationalSolutions ............................ 25

    4.2.4 Operational procedures .. 27 Fuel tankering .................... 27 APU use ............................. 28 Engine warm-upand cool-down periods ...... 29 Reduced Engine Taxiing .... 30 Increased power operationat low aircraft speeds ......... 32 Bleed Air Use ..................... 32 Use of Electrical Power ...... 34 Take-off Flap Setting .......... 354.2.4.9 Departure direction ............ 35 Take-off AccelerationAltitude............................... 36 Approach Procedures ........ 37 Landing Flap Configuration 37 Landing Lights ................... 39 Reverse Thrust ................... 39 Center of Gravity ................ 40 Take-off thrust reduction .... 40 Derated climb .................... 40

    4.3 Maintenance initiatives...41

    4.3.1 Implications of dispatchingunder MEL and CDL ........ 42

    4.3.2 Propulsion SystemsMaintenance .................... 44 Trend monitoring ................ 45 Routine EngineMaintenance ...................... 45


    16 Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340



    #4Efficient aircraft operations require

    the careful integration of many factors

    including regulatory restrictions,

    en-route and airport traffic controlrequirements, maintenance, crew

    scheduling and fuel costs.

    Systematic, effective flight planning

    and careful operation and mainte-

    nance of the aircraft and its engines

    are essential to ensure that all

    requirements are properly addressed

    and that the aircraft is consistently

    being used in the most efficient way


    Like all complex machines, the

    aircraft, as it progresses through

    its operational life, will experience

    performance degradation. Careful

    operation and maintenance can limit

    this degradation and thus reduce

    operational cost.

    This section is the largest section of

    the document and provides advice

    on aircraft operations, operational

    procedures and aircraft maintenance.Initially, fundamental operational prin-

    ciples are reviewed. This is followed

    by discussions of specific proce-

    dures, applicable at various flight

    phases, which can be employed to

    optimize efficiency. The maintenance

    sections discuss timely resolution of

    specific defects that have a notable

    impact on fuel consumption. Finally,

    proposals for reducing aircraft weight

    can be found. It is important to note

    that the implementation of a given

    proposal may affect costs elsewhere

    in the operation: these aspects are

    also highlighted within the discussion

    of each fuel saving initiative.

    Charts provide an insight into the

    potential fuel savings a given initiative

    will bring. The savings are presented

    in terms of kilograms of fuel per

    sector, and for convenience, these

    are subsequently converted to dollarvalues for a wide range of jet fuel

    prices. As mentioned in chapter 2

    the quoted savings are calculated

    for typical mission profiles.



    4.3.3 Airframe Maintenance ..... 46 General .............................. 47 Flight Controls .................... 484.3.3.3 Wing root fairing

    panel seals ......................... 50 Moving surface seals ..........514.3.3.5 Landing Gear Doors .......... 544.3.3.6 Door and Window Seals .... 544.3.3.7 Paint Condition .................. 554.3.3.8 Aircraft exterior cleaning .... 584.3.4 Weight reduction ............. 584.3.4.1 Aircraft INTERIOR cleaning 594.3.4.2 Condensation .................... 594.3.4.3 Cabin Equipment ............... 604.3.4.4 Potable water upload

    reduction ............................ 60 Waste Tank Emptying ........ 60 Other initiatives .................. 61 Air data system accuracy .. 61

    017Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Focus on Airline Fuel Efficiency Teams:_

    As mentioned in the introduction, this document offersa starting point for airlines wishing to optimise their fuelconsumption, emissions and operating costs.

    Fuel saving initiatives are often trade-offs. The fuel saved

    through the implementation of a given initiative usuallyneeds to be assessed in the context of global airlinecost breakdown and business model.

    For example, the choice of flying at a non-optimumspeed (e.g. flying faster to reduce crew costs or recover

    a delay) must balance fuel consumption against bothcrew cost and the cost of reduced aircraft availability(either for flights or maintenance).

    These examples serve to illustrate the value of amulti-function team of airline personnel whose role is to

    weigh the relative costs and other pros and cons of agiven initiative before it is implemented. The same team

    should also co-ordinate the deployment and maintenance

    of initiatives. This approach allows achievable objectives

    to be first established and then implemented whileassuring that all consequences are understood acrossthe airlines organisation. Equally, given the challengesthat will be faced by the airlines fuel efficiency team, it is

    essential that their activities are followed and supported

    by the airlines senior management.

    When is fuel consumed

    during a flight?

    A typical flight includes 6 phases: taxi,take-off and initial climb, climb to cruise

    altitude, cruise, descent, and approach

    & landing.

    The longer the flight, the longer the

    cruise. The following graphs show the

    percentage of the total fuel consumption

    for each flight phase for the three typical

    mission profiles.

    Figure 4-1:

    Fuel consumptionper flight phase




    short sector






    medium sector






    long sector



    Airbus Flight Operations18

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Efficient flight planning that accurately

    and systematically predicts and opti-mizes overall performance for all flights,

    is a key contributor to minimizing costs.

    The flight planning process produces

    Computerized Flight Plans (CFP). CFPs

    are produced, as the name suggests,

    using commercially available software

    or they may be obtained directly from

    a specialist sub-contractor.

    Carefully produced CFPs need to be

    executed with equal care. Following

    a CFP and setting the appropriateparameters in the Flight Management

    and Guidance System (FMGS), will

    contribute to:

    Minimizing direct operating costs,

    Building Flight Crew confidence that

    fuel reserves will be intact on arrival

    thus reducing tendencies to load

    extra fuel.

    Two simple ways of reducing fuel con-

    sumption during flight are given by theoptimization of airspeed and altitude.

    However, these two conditions may

    be difficult to achieve in an operational

    environment. Usually ATC constraints

    prevail. In any case, these aspects must

    be considered from the start and kept

    in mind throughout.

    The Cost Index represents the trade-off

    between the cost of time (crew costs,

    aircraft utilization and other parameters

    that are influenced by flight time) and

    the cost of fuel. It is used to minimize

    the total cost of a flight by optimizing

    speed to obtain the best overall oper-

    ating cost. Although fuel represents ahigh cost per flight it can still be more

    cost effective overall to fly faster, burn-

    ing more fuel, because of a high "cost

    of time".

    A cost index of zero will have the

    aircraft fly at its maximum range capa-

    bility (i.e. most fuel efficient speed), con-

    versely a maximum cost index will have

    the aircraft flying at maximum speed

    (i.e. minimum flight time).

    The Cost Index parameter is entered

    into the aircrafts Flight Management

    System (FMS) and may be varied to

    reflect the specific constraints of a given

    flight. Operators wishing to optimize

    their Cost Index, either for their global

    operation, or for specific sectors, will

    need to make assessments of all rel-

    evant operating costs. Only when this

    has been done can an appropriate

    Cost Index (or Indices) be determined.The Cost Index may be yet further

    optimized in case of departure delays,

    variations in on-route conditions or flight


    An operator who has completed a Cost

    Index review may find that the revised

    figures cannot be fully implemented

    within the current schedule because

    flight times may have increased.



    4.2.2 Cost index

    Notes:_In the interest of clarity 3 cost axes

    are used in the charts accompa-

    nying the operational initiativesdiscussed

    Reference documents:

    Getting to Grips with the Cost Index

    Issue 2 May 1998

    Point of contact:

    [email protected]

    4.2.1 Aircraft operations

    019Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    The fo llow ing factors af fect fuel


    Cruise speed

    (see below for further details)

    Flight level (see section on page 22

    for further details)

    Flight Plan accuracy (see section on

    page 22 for further details)

    Aircraft performance degradation (see

    section on page 23 for further details)

    Fuel reserves (see section on page 23

    for further details)

    Accurate tuning of the flight planning

    system to the aircrafts performance

    and, wherever possible, accurately

    flying the aircraft in accordance withthe Flight Plan may only bring a small

    gain on each flight, but these small

    gains can add up to a measurable and

    valuable gain at the end of the year.

    One important objective that is worth

    repeating is the building of pilot

    confidence in the Computerized

    Flight Planning (CFP).The production

    of an accurate flight plan that precisely

    predicts actual fuel usage will help to

    remove a pilots tendency, which is

    driven by accumulated experience, to

    add some extra fuel reserves on top of

    those already calculated. The subject

    of Fuel Reserves is discussed further

    on page 24.

    Realistic fuel consumption predic-

    tions can be obtained using Airbus

    Performance Engineering Program

    (PEP) software (refer to the followingtext below), for speeds and flight-levels

    as a function of a given cost index,

    aircraft weight, and wind conditions.

    The cost index selected for a given flight

    will determine the speeds and hence

    the time needed to cover the journeys

    distance. The speed must be optimized

    for the flight conditions to minimize the

    overall operating cost.

    Figure 4-2 provides an indication of how

    much additional fuel per flight would be

    consumed if there was a deviation from

    optimum cruise speed of Mach 0.01

    (in this case a cruise speed of Mach

    0.83 instead of 0.82).

    4.2.3 Fuel economy Cruise speed

    Reference documents:

    Getting to Grips with Fuel Economy

    Issue 4 October 2004

    Point of contact:

    [email protected]

    Reference documents:

    Getting to Grips with Fuel Economy

    Issue 4 October 2004Getting to Grips with Aircraft Performance

    Issue 1 January 2002


    500 000

    1 000 000

    1 500 000

    2 000 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00


    Fuel Cost(US$)

    Figure 4-2:

    Increase of 0.01Mach number (0.82 to 0.83)







    AverageSector Length (nm)

    3 520 3 740 4 200

    Annual Cycles 650 640 570

    AdditionalFuel per Sector (kg)

    1 400 1 870 1 150


    AverageSector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    AdditionalFuel per Sector (kg)

    795 945


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160

    AdditionalFuel per Sector (kg)


    Airbus Flight Operations20

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Point of contact:

    [email protected]



    Several references to this software package are made throughout this

    document. Similar software packages are available from other aircraft

    manufacturers but the proprietary nature of the data makes the pack-

    age applicable to the suppliers products only. As such, Airbus PEP soft-ware provides unrivalled degree of precision in the optimization of efficient

    operations of its aircraft.

    The Airbus PEP is composed of several modules:

    Flight Manual (FM): the FM module of PEP represents the performance

    section of the Flight Manual in a digital format for all aircraft (not available

    for A300).

    Take-off and Landing Optimization (TLO): take-off (landing) calcula-

    tion gives the maximum take-off (landing) weight and associated speeds

    for a given aircraft, runway and atmospheric conditions. The performance

    computation is specific to one airframe/engine/brakes combination.

    TLO computes take-off and landing performance on dry, wet and contaminated

    runways (except A300 B2/B2K/B4), taking into account runway characteris-

    tics, atmospheric conditions, aircraft configuration (flap setting) and some

    system failures (Runway and obstacle data are not provided by Airbus).

    Flight Planning (FLIP): produces fuel predictions for a given air distance

    under simplified meteorological conditions. The fuel prediction accounts

    for operational fuel rules (diversion fuel, fuel contingency, etc.), for airline

    fuel policy for reserves and for the aircraft performance level. Typical

    fields of application are technical and economic feasibility studiesbefore opening operations on a route.

    In Flight Performance (IFP): computes general aircraft in-flight perfor-

    mance for specific flight phases: climb, cruise, descent and holding.

    The IFP works from the aircraft performance database for the appropriate

    airframe/engine combination. The IFP can be used to extract digital

    aircraft performance data to be fed into programs specifically

    devoted to flight planning computation.

    Aircraft Performance Monitoring (APM): evaluates the aircraft performance

    level with respect to the manufacturers book level. Based on a statisticalapproach, it allows the operator to follow performance degradation over

    time and trigger maintenance actions when required to recover in-flight

    performance. This tool measures a monitored fuel factor which is used

    to update the aircraft FMS "PERF FACTOR" as well as the fuel

    consumption factor for the computerized flight plan.

    Operational Flight Path (OFP): this module is designed to compute

    the aircraft operational performance. It provides details on all engine

    performance and also on engine out performance. This engineering

    tool gives the actual aircraft behaviour from brake release point or

    from any point in flight. It allows the operations department to check the

    aircraft capabilities for flying from or to a given airport, based onoperational constraints (Noise abatement procedures, standard

    instrument departure, etc.) (Not available for A300).

    021Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Modern commercial jet engines,

    including those fitted to Airbus A330/

    A340 Family are most efficient at high

    altitude. The Optimum Flight Level is

    the altitude that will enable the aircraft,

    at a given weight, to burn the lowest

    amount of fuel over a given distance. It

    can be accurately computed for given

    flight conditions using the In-Flight

    Performance (IFP) module of the Airbus

    Performance Engineering Program

    (PEP) software package (see section

    on page 21 for more information). This

    information should systematically be

    incorporated into the Flight Plan.

    ATC constraints may prevent flight at

    this optimum altitude, but the principle

    should be accurately followed whenever

    possible. Nonetheless, the Flight Plan

    should always be an accurate rep-

    resentation of the actual flight being

    undertaken and include all known ATC

    constraints. Flight Level

    Figure 4-3:

    2000 ft below optimumflight level

    Reference documents:

    Getting to Grips with Fuel EconomyIssue 4 - October 2004

    Getting to Grips with Aircraft PerformanceIssue 1 - January 2002

    FCOM Performance PER-CRZ-ALT-10

    Point of contact:

    [email protected]


    200 000

    600 000

    400 000

    800 000

    10 000 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00


    Fuel Cost(US$)







    AverageSector Length (nm)

    3 520 3 740 4 200

    Annual Cycles 650 640 570

    AdditionalFuel per Sector (kg)

    840 520 370


    AverageSector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    AdditionalFuel per Sector (kg)

    600 310


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160

    AdditionalFuel per Sector (kg)


    Airbus Flight Operations22

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    With time the airframe and engine deteri-

    orate such that the aircraft requires more

    fuel for a given mission. These deterio-

    rations can be partially or fully recovered

    through scheduled maintenance actions.Deterioration will begin from the moment

    the aircraft enters service and the rate

    will be influenced by the utilization andoperation of the aircraft.

    The Aircraft Performance Monitoring(APM) module of the Airbus Performance

    Engineering Program (PEP) softwarepackage (see section on page 21 formore information) allows calculation ofaircraft degradation over time. It canalso be used as a means of triggering

    maintenance actions to recover some

    of the degradation.

    The implementation of an AircraftPerformance Monitoring programrequires the processing of data through

    the APM software. The required data,

    known as "cruise points", are automati-

    cally recorded by the aircraft. Depending

    on the aircrafts configuration, the trans-

    fer of these data can be achieved viaeither printouts from the cockpit printer,

    a PCMCIA card or diskette, or via theACARS system.

    The performance degradation foreach individual aircraft is an important

    parameter. Accurate interpretation ofthis factor will enable the fuel usage

    predictions of the Flight ManagementSystem (FMS) to better match those of

    the CFP system.

    Knowledge of performance levels can

    also facilitate an operators discussions

    with their local Airworthiness Authority

    regarding the decrease of fuel reserves

    from a general 5% of the trip fuel to 3%

    (see also Airbus Consulting Services on

    page 25).

    In terms of aircraft operation, an accu-

    rate, Computerized Flight Plan (CFP) is

    one of the most important means ofreducing fuel burn.

    As is the case with most computersystems, the accuracy of the data pro-vided to a CFP system will influencethe accuracy of the CFPs it produces.

    However, the nature of some of theparameters can bring a certain degree

    of inaccuracy.

    For example:

    Weather conditions: particularlytemperatures and wind strengths/directions.

    Fuel specification (lower heating value):

    defines the heat capacity of the fuel.Engine thrust depends on the amountof heat energy coming from the fuel

    it is burning. The aircraft databasemay contain a standard or averagevalue that may not correspond to the

    actual fuel used. A fuel analysis or data

    from the fuel provider can provide the

    necessary clarification. Inclusion of actual ATC constraints.

    Up-to-date aircraft weight: aircraftweighing is a scheduled maintenance

    action and the latest data should be

    systematically transferred to the CFP

    system. Payload estimation: assessment

    of passenger baggage and cargovariations with route and season.

    Aircraft performance degradation:refer to following section.

    Fuel reserves: refer to section

    below. Aircraft performancedegradation Flight Plan accuracy

    Reference documents:

    Getting to Grips with Aircraft Performance

    Monitoring Issue 1, January 2003

    Point of contact:

    [email protected]

    023Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Part of any extra fuel transported to a

    destination is just burnt off in carryingitself. It is not uncommon for flight crew

    to uplift additional "discretionary" fuelbeyond that called for by the Flight Plan.

    These discretionary reserves represent

    additional weight that must be trans-ported to the destination.

    The practice of adding discretionary

    reserves may be the result of accumu-

    lated experience that produces a lack of

    faith in the fuel usage predictions made

    by the flight planning system (sources

    of inaccuracy in flight plans were listed

    in the previous page). Of course, when

    reserves beyond those described in the

    flight plan are added, the flight plan pre-

    dictions automatically become invalid.

    Equally if the flight plan is not or cannot

    be precisely followed its predictions will

    also be no longer valid. Consequently

    all fuel reserves including discretionary

    reserves, should be included in the Flight

    Plan as should all expected flight restric-

    tions (flight level, holding time, etc.).

    Reserve requirements vary between

    aviation authorities. Some Aviation

    Authorities allow a procedure known as

    "Reclearance in Flight" on some routes.

    This procedure can reduce the reserves

    required for a given route and should be

    considered when appropriate. Fuel reserves

    Figure 4-4:

    Per additional1000 kg fuel reserve


    50 000

    150 000

    100 000

    200 000

    250 000

    300 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00


    Fuel Cost(US$)







    AverageSector Length (nm)

    3 520 3 740 4 200

    Annual Cycles 650 640 570

    AdditionalFuel per Sector (kg)

    210 270 265


    AverageSector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    AdditionalFuel per Sector (kg)

    155 155


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160


    Fuel per Sector (kg)85

    Airbus Flight Operations24

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    2ndPhase1stPhaseDiagnosis Monitoring

    Data & process analysis,

    Indentification of initiatives,

    Define areas of improvement

    & establish recommendations,

    quick wins and KPIs


    Operational analysis

    per flight phase


    Follow, control & report

    the implementationof initiatives


    Ensure correct use of adopted



    Continuous monitoring to ensure

    promotion of fuel and flight

    efficiency measures

    , Airbus Operational Solutions



    In 2009 Airbus launched a new service for operators wishing to optimise

    their Fuel and Flight Efficiency.

    Airbus is able to provide its customers with assistance on the identification

    and implementation of best practices in the operational domains of flight

    preparations, flight operations and maintenance & engineering. Thanks to its

    position of OEM Airbus is able to identify the latest recommendations and

    tailor them to the airlines specific operations by performing detailed trade-

    offs to fine-tune and measure all fuel, time and maintenance related costs.

    A dedicated team of Airbus specialists will work in close contact with the

    airline, following a modular approach consisting of two main phases that are

    customized to each customers context and objectives.

    The objective of the Fuel & Flight Efficiency Diagnostics service

    is to help operators improve fuel usage and more globally to reduce costs.This service includes an analysis of each flight phase and the relevant

    flight parameters, a pre/post flight assessment and where necessary an

    evaluation of the cost index.

    Recommendations will be made in the Flight Operations, Flight planning

    and maintenance and engineering domains.

    Airbus has assisted airlines to monitor and track various initiatives

    and developed KPIs to measure fuel and flight efficiency as well

    as providing benchmark data for comparative purposes.

    A typical Fuel & Flight Efficiency service consists of:

    Data collection and data analysis (where applicable)

    Analysis of current procedures to find areas of improvement Interviews with key departments and flight observation

    Identification of initiatives and assessment of expected benefits

    Tracking and monitoring with KPIs and benchmark elements

    025Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Aircraft operations fuel optimization action overview:_The following actions have been described in the preceding sectionsand should be implemented to ensure a systematic reduction in fuelconsumption on each flight:

    Calculate Computerized Flight Plan (CFP) with Cost Index of flight,

    Accurately follow the speed and altitude schedules defined by the CFP,

    Regularly monitor aircraft performance to determine performancefactors to be used by Flight Management System (FMS) and CFPsystem and to identify aircraft performance trends,

    Use Airbus PEP software to validate optimum speeds and altitudes

    used in CFP, Optimize and regularly validate all other CFP system parameters,

    Review fuel reserve requirements with local authorities andoptimize for each flight,

    Minimize discretionary fuel reserves and include all reserves in CFP.

    Such a service has already assisted many airlines to improve their costs

    and even those airlines which already have considerable experience in

    the fuel and flight efficiency domain have benefited.

    The Monitoring Service will provide regular reports with information and

    advice on the use of current initiatives employed by the operator. This service

    will help keep track of the use of current initiatives and the benefits they

    bring whilst more detailed reporting will provide further recommendationsand summarise cost savings.

    In addition, Airbus can compare your data with benchmarking elements

    and current best industry practices and also identify further areas for


    Such a service is ideal for an airline which already has fuel and flight

    efficiency initiatives in place but is unable to monitor them fully.

    Both services complement each other very well.

    Airbus Fuel and Flight Efficiency Consulting Services guarantees operators

    a rapid return-on-investment thanks to substantial savings in Direct Operating

    Costs, without ever compromising safety. Airbus is fully committed toproviding the best-in-class solutions to its Customers; this is why an array

    of specific elements has been developed for the fuel and Flight Efficiency

    services, including:

    Definition of best practices developed with different Airbus Customers

    Benchmarking elements comparison with industry standards

    Use of dedicated tools

    Airbus Consulting Services offer a customized approach that is adapted

    to the context and environment of the Customer. Airlines may request full

    guidance for identification of potential savings and implementation of fuel

    initiatives. On the other hand, airlines with more advanced fuel efficiency

    management processes may prefer to request Airbus support to validate

    their current initiatives with a quantified status on fuel efficiency and identify

    new opportunities for improvement.

    Airbus Fuel and Flight Efficiency Consulting Services are a part of

    a comprehensive portfolio of services covering the whole array of airline

    activities (maintenance and engineering, flight operations, material and

    logistics, training) and range from "organizational assessment" up to

    "capability assistance".

    Airbus point of contact:

    Airbus Flight Operations26

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Having considered the main factors that can influence fuel consumption we

    now consider operating procedures that can also play a part in reducing either

    the fuel bill or the operational cost.

    4.2.4 Operational procedures

    Usually the message is, to minimize fuel

    burn it is most economical to carry the

    minimum required for the sector. Onthe other hand, there are occasionswhen it is, in fact, more cost effectiveto carry more fuel. This can occur when

    the price of fuel at the destination issignificantly higher than the price at the

    point of departure. However, since the

    extra fuel on board leads to an increase

    in fuel consumption the breakeven point

    must be carefully determined.The PEP FLIP module (see section on

    page 21 for details) assist in determining

    the optimum fuel quantity to be carried

    as a function of initial take-off weight(without additional fuel), stage length,cruise flight level and fuel price ratio. Fuel tankering

    Reference documents:

    Getting to Grips with Fuel Economy

    Issue 4 October 2004

    Point of contact:

    [email protected]

    027Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Ground power and air are usually

    significantly cheaper per hour than theAPU (when considering both fuel and

    maintenance costs). Consequently

    the moment of APU and engine start

    should be carefully optimized with

    neither being switched on prematurely.

    Monitoring average APU usage per

    sector can be a useful tool.

    The availabil ity and use of ground

    equipment for the provision of both

    air and electrical power should be

    re-evaluated at all destinations and thepossibility of obtaining and operating

    additional ground equipment where

    necessary should not be dismissedwithout evaluation.On ground, the APU burns 140 kg/h

    (A330 and A340-200/300) to 210 kg/h

    (A340-500/600) if used only for elec-trical power and 215 kg/h (A330 and

    A340-200/300) to 290 kg/h (A340-500/600) if used for both electricalpower and air conditioning.

    The following example illustrates the

    cost of jet fuel for 10 minutes of APUuse. It is worth noting that in addi-tion to the fuel saved by this initiative,

    CO2emissions would also be reduced(10 to 15 kg of CO2saved per minute

    of APU operation). APU use

    Reference documents:

    Getting to Grips with Fuel Economy

    Issue 4 October 2004

    Figure 4-5:

    Ten minutes less APU use per flight


    10 000

    20 000

    50 000

    40 000

    30 000

    60 000

    70 000

    80 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00

    AnnualFuel Saving








    AverageSector Length (nm)

    3 520 3 740 4 200

    Annual Cycles 650 640 570

    Fuel Saved

    per Sector (kg)

    35 50 50


    AverageSector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    Fuel Savedper Sector (kg)

    35 50


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160

    Fuel Savedper Sector (kg)


    Airbus Flight Operations28

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    An engine needs time for all com-

    ponents to reach their operatingtemperature. Furthermore the various

    components will expand and contract

    with temperature at different rates.

    Minimum warm-up and cool-down peri-

    ods have been determined to minimize

    heavy or asymmetrical rubbing at take-

    off or rotor seizure after shutdown.

    Such rubbing would increase running

    clearance that in turn would lead tolosses in efficiency and increased fuel

    consumption. Engine warm-up and cool-down periods

    Reference documents:


    Point of contact:

    [email protected]

    Table 4-1:

    Overview of engine warm-up

    and cool-down times(reference only)


    Engine Start(from cold followingprolonged shutdown

    or for warm Engine)

    At or near Idle for between3 to 5 minutes (depending uponengine type) before advancing

    to higher power thrust*

    At or near Idle for between2 to 5 minutes (depending uponengine type) before advancing

    to higher power thrust*

    Standard OperatingProcedures (After Start)PRO-NOR-SOP-09


    Engine Shutdown(after Landing)

    At or near Idle or low powerfor between 1 to 5 minutes(depending upon engine type)before engine shut down**

    At or near Idle or low powerfor between 3 to 5 minutes(depending upon engine type)before engine shut down**

    Standard OperatingProcedures (Parking)PRO-NOR-SOP-22


    FCOM ReferenceA330 A340

    * Taxi time at idle may be included in the warm up period **Taxi time at idle may be included in the cool down period

    029Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    At large or busy airports where the

    taxi time to and from the runway can

    often exceed 15 minutes single engine

    taxi can bring considerable benefits.

    This procedure would also be benefi-cial to brake units consumption costs

    (brake wear and brake oxidation).

    For single engine taxi we must con-

    sider two different cases with different

    constraints: taxi in and taxi out.

    Taxi out:the aircraft is heavy and

    it may be more difficult to taxi and

    perform turns. In addition, in case of

    frequents stops, the required thrust

    to make the aircraft move again maybe excessive with associated possible

    FOD or jet blast damage.

    For taxi out, it is also recommended

    keeping the APU running for sec-

    ond engine start (to avoid X BLEED

    start with thrust increase on sup-

    plying engine), which reduces

    the fuel economy by 150 kg / hr.

    Last but not least, late detection of

    some failure is also to be considered.

    This is mainly applicable to HYD and

    F/CTL failures.

    Taxi in: Single engine taxi in is

    easier to perform (lighter aircraft).

    There is no issue with engine start,

    no failure to be detected late.

    Only controllability (turns on running

    engine side), operation on contam-

    inated taxiway, situation requiring

    excessive thrust (uphill slope) or in

    case of probable FOD (taxiway andshoulders in bad condition) may pre-

    vent single engine taxi-in. Reduced Engine Taxiing

    Focus on Flight CrewDocumentation for FuelEfficiency:_

    A clear airline demand for procedural

    documentation to support thedeployment in daily operations ofthe fuel saving techniques outlined

    in this document has now been met

    with the introduction of the "GreenOperating Procedures" (GOPs).

    They can be found in the supple-mentary procedures sections ofthe Flight Crew Operating Manuals

    (FCOM PRO-SUP-93) and FlightCrew Training Manuals (FCTM SI-100).

    The GOPs provide detailed guidance

    to flight crews for procedures thatcan contribute to fuel savings.Theguidance includes advice on thefactors that should be consideredbefore using a specific procedurebut it remains the responsibilityof each airline to adapt theseprocedures to their operations.

    As is the case with all flight crewdocumentation the GOPs will evolve

    as new technologies, environmental

    changes, regulation evolutions, new

    fuel saving opportunities, etc. areintroduced.

    Airbus Flight Operations30

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    In any case, various factors need to

    be considered before such a policy is


    Engine start-up, warm up and cool

    down times must be respected. Not suitable for crowded ramps:

    due to reduct ion in a i rcraf t


    Increased thrust setting on operational

    engine may increase ingestion of dust

    particles (refer to following section).

    As is the case with reduced APU use,

    this initiative can also contribute to

    reduce CO2emissions in and around

    the airport terminal area. Reduced

    engine taxi can reduce CO2emissions

    by 25 to 55kgs per minute (refer to the

    text box "Focus on CO2" on page 12 for

    additional information).

    Reference documents:

    Getting to Grips with Fuel Economy

    Issue 4 October 2004

    FCOM Procedures PRO-SUP-93-20

    Point of contact:

    [email protected]

    Figure 4-6:

    Reduced engine taxiingfor 10 minutes per flight


    50 000

    100 000

    150 000

    200 000

    250 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00

    AnnualFuel Saving








    AverageSector Length (nm)

    3 520 3 740 4 200

    Annual Cycles 650 640 570

    Fuel Savedper Sector (kg)

    80 100 180


    AverageSector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    Fuel Savedper Sector (kg)

    80 100


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160

    Fuel Savedper Sector (kg)


    031Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Operating an engine at increased power

    whilst the aircraft is stationary or taxiing

    at low speed increases suction and the

    likelihood of ingesting:

    Particles that will erode airfoils orblock High Pressure Turbine (HPT)

    blade cooling holes,

    Foreign objects that could cause aero

    foil damage.

    Once again these effects will lead to

    losses in engine efficiency and increase

    in fuel consumption. To minimize these

    effects the following measures should

    be considered: Early de-selection of MAX reverse

    thrust to IDLE reverse (refer also to

    Thrust Reverse section on page 34),

    Avoiding high thrust excursions

    during taxi,

    Progressive thrust increase with

    ground speed during take-off


    Use of the Environmental Control

    System (ECS) will increase engine

    or APU fuel consumption. Air for the

    ECS packs is taken, or bled, directly

    from the engine or APU compressors.

    Generation of this additional hot, com-

    pressed air requires more work to be

    done by the engines or APU and to

    achieve this, more fuel must be burnt. Increased power operation at low aircraft speeds Bleed Air Use

    Point of contact:

    [email protected]

    Figure 4-7:

    Take-off without bleed


    2 000

    6 000

    4 000

    8 000

    10 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00

    AnnualFuel Saving









    Sector Length (nm)3 520 3 740 4 200

    Annual Cycles 650 640 570

    Fuel Savedper Sector (kg)

    5 5 10


    AverageSector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    Fuel Savedper Sector (kg)

    5 5


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160

    Fuel Savedper Sector (kg)


    Airbus Flight Operations32

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Single pack operation on ground can

    save some fuel, however it highly

    depends on environmental conditions.

    For operations with air conditioning

    pack on ground under APU BLEED,

    the APU BLEED supplies more air than

    required in standard conditions to cool

    the cabin. In standard stabilized condi-

    tions, even with full passenger load, the

    APU demand is already minimal with 2Packs running, and switching 1 Pack

    off will result in dumping air out of the

    system, but will not change the bleed

    demand on the APU.

    Economy on fuel burn will be obtained

    in cases where the APU demand is

    high, for example in non-stabilized sit-

    uations where the cabin is hot, and the

    requested temperature is lower:

    Having 2 Packs running will burn

    more fuel but improve the coolingefficiency

    Switching off 1 Pack will result in fuel


    However, it is extremely difficult, if not

    impossible, to predict the exact bleed

    demand, as too many variables will

    affect the cooling demand, including

    cabin layout/density, daytime, ambient

    temperature, weather conditions, cargo

    cooling selection, selected cabin tem-

    perature, installed/activated IFE/lights,

    other heat loads like galley etc., win-

    dow blinds shaded. Normal lifetime

    deterioration like e.g. pack heat-ex-

    changer contamination also has to be


    On the contrary, in standard stabilized

    conditions, switching off 1 Pack with

    APU BLEED ON will not result in fuelburn reduction. The difference on APU

    demand is too low to see significant

    savings in APU fuel consumption.

    When air conditioning is provided by the

    engines, single pack operation is notto be considered on A340 and A330equipped with GE and PW engines, asin this case the minimum ground idlethrust is automatically increased, lead-ing to an increase in fuel consumption.

    This is not the case on A330 equippedwith RR engines, and the fuel savingexpected from single pack operation

    highly depends on environmental con-

    ditions(OAT, desired cabin temperature,

    passengers number, airport elevation...)

    Take-off with the air conditioning packs

    switched off can reduce fuel consumption

    or allow take-off thrust to be optimized

    (Packs would be selected ON during

    initial climb).

    Reference documents:

    Getting to Grips with Fuel Economy

    Issue 4 October 2004

    Getting to Grips with Aircraft Performance

    Issue 1 January 2002

    Point of contact:

    Aircraft performance:

    [email protected]

    033Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    When assessing this option, the actual

    cabin temperature and its effect on pas-

    senger comfort should be considered.

    The economic mode (select "LO" or

    "ECON" Pack Flow) reduces pack

    flow rate by 20% (with an equivalent

    reduction in the amount of air takenfrom the engines). This mode can be

    used on flights with reduced load fac-

    tors: less than 60% of the seats in the

    economy class but not more than 200

    passengers in all classes for A330 and

    A340-200/300. For A340 500/600, the

    pack flow is automatically adjusted to

    the number of passengers entered in

    the MCDU.

    However, single pack operation is gen-

    erally not recommended.

    Electrical power is generated by the

    IDGs, led by the engines. It seems then

    obvious that the use of electrical power

    increases the fuel consumption.

    However, this increase in fuel con-

    sumption is low, approximately 0.1%

    per 10 kW, not worth trying to imple-

    ment any measure in this area, which

    moreover would be at the expense of

    passengers comfort for interior lighting,

    or of safety for exterior lighting. Use of Electrical Power


    50 000

    200 000

    150 000

    100 000

    250 000

    300 000

    350 000

    400 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00

    AnnualFuel Saving


    Figure 4-8:

    Pack Flow selection(LO versus NORM)







    AverageSector Length (nm)

    3 520 3 740 4 200

    Annual Cycles 650 640 570

    Fuel Savedper Sector (kg)

    210 260 370


    AverageSector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    Fuel Savedper Sector (kg)

    150 160


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160

    Fuel Savedper Sector (kg)


    Airbus Flight Operations34

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Ideally departure should be in direc-

    tion of the flight. Most airports have

    Standard Instrument Departure (SID)

    routes that ensure terrain clearance or

    noise abatement requirements are met.

    The main departure route will usually be

    the least demanding in terms of aircraft

    performance. Certain combinations

    of destination/wind direction/depar-

    ture direction can lead to a departure

    route that adds several miles to the

    flight distance. At many airports, alter-

    nate departure routes are available for

    use when conditions allow. However,

    their use may require a greater climb


    The lowest flap setting for a given

    departure will produce the least drag

    and so give the lowest fuel burn, lowest

    aircraft generated noise and best flight

    profile. However other priorities such as

    maximizing take-off weight, maximizing

    flex temperature, maximizing passenger

    comfort, minimizing take-off speeds,

    minimizing ground noise, etc will often

    require higher flap settings.

    The most appropriate flap setting

    should be selected for each departure

    rather than systematic use of the same

    configuration. Departure direction Take-Off Flap Setting

    Point of contact:

    [email protected]

    Reference documents:

    Getting to Grips with Fuel EconomyIssue 4 October 2004

    Getting to Grips with Aircraft PerformanceIssue 1 January 2002

    Point of contact:

    [email protected]


    10 000

    40 000

    30 000

    20 000

    50 000

    60 000

    70 000

    80 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00

    AnnualFuel Saving


    Figure 4-9:

    Take-off with CONF 1+Fcompared with CONF 3







    AverageSector Length (nm)

    3 520 3 740 4 200

    Annual Cycles 650 640 570

    Fuel Savedper Sector (kg)

    25 50 50


    AverageSector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    Fuel Savedper Sector (kg)

    25 50


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160

    Fuel Savedper Sector (kg)


    035Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Figure 4-10:

    Using 800 ft accelerationaltitude instead of 1 500 ft

    The aircrafts climb to its cruising alti-

    tude is typically achieved in three basic

    steps. Following take-off, the aircraft will

    climb to what is known as the "accel-

    eration altitude". Once at acceleration

    altitude, the aircrafts climb rate is

    temporarily reduced while its speed is

    increased to the normal climb speed.

    Once this speed is reached, the climb

    rate is increased so that the chosen

    cruising altitude can be achieved quickly

    and efficiently.

    In many places, ATC restricts the speed

    below 10000 ft to 250 kt, while the opti-

    mum climb speed is around 300 kt.

    It is however possible to ask for a higher

    climb speed in particular in case of low

    traffic in the area.

    A low acceleration altitude will minimize

    fuel burn because arrival at the acceler-

    ation altitude also implies that the flaps

    and slats are retracted. These devices

    are used to optimize the initial climb

    but they have the effect of increasing

    drag, so, the earlier they are retracted

    the sooner the aircraft enters a more

    efficient aerodynamic configuration.

    However, ATC constraints or noise

    abatement requirements may often

    preclude the use of a lower acceleration

    altitude. Take-off Acceleration Altitude

    Reference documents:

    Getting to Grips with Fuel EconomyIssue 4 October 2004

    Getting to Grips with Aircraft PerformanceIssue 1 January 2002

    Point of contact:

    [email protected]


    25 000

    20 000

    15 000

    10 000

    5 000

    30 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00

    AnnualFuel Saving








    AverageSector Length (nm)

    3 520 3 740 4 200

    Annual Cycles 650 640 570

    Fuel Savedper Sector (kg)

    10 20 25



    Sector Length (nm)

    2 550 2 400

    Annual Cycles 790 820

    Fuel Savedper Sector (kg)

    10 20


    AverageSector Length (nm)

    1 530

    Annual Cycles 1 160

    Fuel Savedper Sector (kg)


    Airbus Flight Operations36

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    A number of fuel saving measures

    should be considered for the aircrafts


    The aircraft should be kept in an aer-

    odynamically clean configuration as

    long as possible with landing gear

    and flaps only being deployed at the

    required moment.

    A continuous descent will minimize

    the time the aircraft spends at a

    non-optimum altitude and projects

    to study how this can be achieved

    with increased regularity within a

    congested air traffic environment are

    underway (ref. section 3, Industry

    Issues, page 10).

    Airbus aircraft include equipment

    providing a high navigation accu-

    racy. Specific procedures, called RNP

    (Required Navigation Performance)

    can be developed and implemented,

    allowing to reduce the distance flown

    during take-off and/or approach.

    A RNP approach procedure can save

    up to 300 kg fuel per approach com-

    pared with the traditionally published

    instrument approach.

    Visual approaches should also be

    considered, as airport instrument

    approach paths do not always offer

    the most direct route to the runway.

    Where conditions enable its use,

    "CONF 3" flap configuration will allow

    fuel to be saved because it is more aer-

    odynamically efficient than the "CONF

    FULL" flap configuration which allows

    lower approach and landing speeds,

    thus shorter landing distances. It isto be noted however that low visibil-

    ity landings of categories CAT II and

    CAT III nominally require "Conf FULL"

    flap configuration.

    Furthermore, the following operational

    and economic constraints should be

    considered when adopting a "Conf 3"

    flap configuration at landing:

    Aircraft landing weight,

    Available runway length,

    Suitability of "LOW" automatic brak-ing (reduced deceleration, increased

    landing distance),

    Preferred runway exit point (potential

    increase in runway occupancy and

    block times),

    Runway surface conditions (effect on

    brake efficiency),

    Tailwinds (effect on landing ground

    speed and distance). CONF3 willincrease energy absorbed by the

    brakes, as a consequence the fol-

    lowing should be monitored:

    - Additional brake cooling time

    (increase in Turn-Around-Time),

    - Potential increase in brake and tire


    - Potential risk of damage to brakes

    due to high brakes temperatures. Approach Procedures Landing Flap Configuration

    Point of contact:

    [email protected]

    Point of contact:

    [email protected]

    Reference documents:

    Getting to Grips with Fuel Economy

    Issue 4 October 2004

    Reference documents:

    Getting to Grips with Fuel EconomyIssue 4 October 2004

    Getting to Grips with Aircraft PerformanceIssue 1 January 2002

    Point of contact:

    [email protected]

    Reference documents:

    Getting to Grips with Required Navigation

    Performance with Authorization Required

    Issue 2 February 2009

    Important Note:_In order to maximize safety margins the Airbus FCOM (Flight CrewOperating Manual) recommends the use of the FULL configuration forall landings. Nonetheless, where runway length and conditions arefavorable configuration 3 may be considered.

    037Airbus Flight Operations

  • 7/24/2019 Performance Retention and Fuel Saving A330 A340


    Figure 4-11:

    Landing in Conf 3instead of Conf FULL

    Focus on Balancing Costs:_Sections and (Landing Flap Configuration and Reverse

    Thrust) both discuss initiatives that can bring worthwhile fuel savings. How-

    ever, the potential cost of achieving these savings must not be ignored.

    A normal consequence of applying either of the referenced initiatives willbe an increase in landing distance. An increase in landing distance couldmean that the normal runway exit cannot be used and possibly increasethe block time for the flight. For many airlines an increase in block time willmean an increase in flight crew pay for the flight in question. This additional

    cost must be weighed against the saving made in fuel cost.

    Use of conf 3 and idle reverse will lead to an increase of the brake tem-perature and wear.

    An increased brake temperature may lead to departure delays (brakesmust be allowed to cool down to acceptable levels before departure) and/or increased thermal oxidation of the brake carbon (leading to possibleunscheduled, premature brake removal and even brake disc rupture).Increased brake and tire wear would be expected to increase the "perlanding" cost of these components and, once again, the additional costmust be weighed against the saving made in fuel cost.

    Reference documents:

    ISI 32.42.00002 Carbon Brakes Thermal Oxidation

    Operational Procedures Impact

    Point of contact:

    (Brake System Engineering)

    [email protected]


    25 000

    20 000

    15 000

    10 000

    5 000

    30 000

    Fuel Price (US$ per US Gallon)

    1.00 2.00 3.00 4.00 5.00

    AnnualFuel Saving