performance retention and fuel saving a330 a340

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

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Airbus Flight OperationsJune 2015

Getting to grips with

performance retention

and fuel saving

A330/A340 Family


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#1#2

#3

#4#5

Scope

p.003

Introduction

p.004

Industry Issues

p.010

Fuel saving opportunitiesp.017

Summary & Conclusions

p.062

Appendices

p.064

Contents


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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


4/68


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#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

stakeholders.

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


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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


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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

Thrust

Weight

Drag

Lift

Airbus Flight Operations 005


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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)

20140

0.5

1

1.5

2

2.5

3

3.5

0

20

40

60

80

100

120

140

US$

per USGallon

US$ perBarrel



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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

economies.

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%

25%

28%

Nav./Landing

Maintenance

Fuel

Crew 14%

19%

19%

43%

Nav./Landing

Maintenance

Fuel



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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.

0

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

(US$)

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.

from

A330-200

to A330-300

from

A340-300

to A340-200

from

A340-600

to A340-500

Long107% 96%

93%

Medium

Short 106%

LongA330

200

A340

300

A340

600

AverageSector Length (nm)

3 520 3 740 4 200

Annual Cycles 650 640 570

Average Trip Time (hours) 7.6 8.1 9.1

Medium


2 550 2 400

Annual Cycles 790 820

Average Trip Time (hours) 5.6 5.2

Short


1 530

Annual Cycles 1 160

Average Trip Time (hours) 3.4



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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:

www.airbusworld.com (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



12/68

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

Industry

issues#3



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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 4.2.3.6) seeks to identify

and implement fuel savings through a

combination of route improvements,infrastructure enhancements, reduced

flight times and operational efficiency

recommendations.

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.

FURTHER READING

IATA Guidance Material and Best

Practices for Fuel and

Environmental Management,

3rdEdition May 2008.

WEB SITES

Cleansky:www.cleansky.eu

SESAR: www.sesarju.eu

NextGen: www.faa.gov/nextgen

AIRE: www.sesarju.eu/environment/aire

Airbus ProSky:

www.airbusprosky.com

Metron Aviation:

www.metronaviation.com

IATA: www.iata.org

A4A: www.airlines.org

Airbus points of contact:

Upgrade Services:

[email protected]

Airbus Fuel and Flight Efficiency

Consulting Services:

[email protected]



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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.

3.1 ENVIRONMENTAL ISSUES

_

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.

0

10

20

30

40

50

60

Energy Industry Roadtraffic

Aviation Othermeans oftransport

Othersources

%

Variation between studies

Figure 3-1:

Human activities contribution toCO2emissions. Sources: IPCC,

UNFCCC, IEA and DLR.



15/68

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.

FURTHER READING

Getting to grips with Aircraft noise Issue 1, December 03

WEB SITES

Airbus: www.airbus.com/en/corporate/ethics/environment/index.html

ICAO: www.icao.int/env

Other: www.enviro.aero

FOR FURTHER

INFORMATION on EU-ETS

visit the website of the

European Commission:

http://ec.europa.eu/clima/policies/transport/aviation/

index_en.htm

FOR AIRBUS INPUT on ETS

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.



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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

China.

3.2 ALTERNATIVE SOURCES FOR JET FUELS

_



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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, www.enviro.aero)

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,

www.enviro.aero)

FOR FURTHER INFORMATION ON ALTERNATIVE FUELS

VISIT THE FOLLOWING WEBSITES:

Airbus: www.airbus.com/company/environment/

Industry:www.enviro.aero

IATA:www.iata.org/whatwedo/environment/Pages/alternative-fuels.aspx

ICAO: www.icao.int/icao/en/Env2010/ClimateChange/AlternativeFuels.htm

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

Feedstockgrowth

Flight

Flight

Transport

Transport

Processing

Extraction

Refining

Refining



18/68

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

4.2.3.1 Cruise speed...................... 20

4.2.3.2 Flight Level ......................... 22

4.2.3.3 Flight Plan accuracy ........... 23

4.2.3.4 Aircraft performancedegradation........................ 23

4.2.3.5 Fuel reserves...................... 24

4.2.3.6 Airbus OperationalSolutions ............................ 25

4.2.4 Operational procedures .. 27

4.2.4.1 Fuel tankering .................... 27

4.2.4.2 APU use ............................. 28

4.2.4.3 Engine warm-upand cool-down periods ...... 29

4.2.4.4 Reduced Engine Taxiing .... 30

4.2.4.5 Increased power operationat low aircraft speeds ......... 32

4.2.4.6 Bleed Air Use ..................... 32

4.2.4.7 Use of Electrical Power ...... 34

4.2.4.8 Take-off Flap Setting .......... 354.2.4.9 Departure direction ............ 35

4.2.4.10 Take-off AccelerationAltitude............................... 36

4.2.4.11 Approach Procedures ........ 37

4.2.4.12 Landing Flap Configuration 37

4.2.4.13 Landing Lights ................... 39

4.2.4.14 Reverse Thrust ................... 39

4.2.4.15 Center of Gravity ................ 40

4.2.4.16 Take-off thrust reduction .... 40

4.2.4.17 Derated climb .................... 40

4.3 Maintenance initiatives...41

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

4.3.2 Propulsion SystemsMaintenance .................... 44

4.3.2.1 Trend monitoring ................ 45

4.3.2.2 Routine EngineMaintenance ...................... 45

Content

16 Airbus Flight Operations


19/68

FUEL SAVINGOPPORTUNITIES

#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

possible.

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.

4.1 INTRODUCTION

_

4.3.3 Airframe Maintenance ..... 46

4.3.3.1 General .............................. 47

4.3.3.2 Flight Controls .................... 484.3.3.3 Wing root fairing

panel seals ......................... 50

4.3.3.4 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

4.3.4.5 Waste Tank Emptying ........ 60

4.3.4.6 Other initiatives .................. 61

4.3.4.7 Air data system accuracy .. 61



20/68

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

2%Taxi3%Descent

Cruise

Climb

short sector

72%

23%

1%Taxi2%Descent

Cruise

Climb

medium sector

81%

16%

1%Taxi1%Descent

Cruise

Climb

long sector

88%

10%



21/68

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

profile/route.

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 OPERATIONAL INITIATIVES

_

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



22/68

The fo llow ing factors af fect fuel

consumption:

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

4.2.3.1 Cruise speed


Getting to Grips with Fuel Economy

Issue 4 October 2004

Point of contact:

[email protected]



Issue 4 October 2004Getting to Grips with Aircraft Performance

Issue 1 January 2002

0

500 000

1 000 000

1 500 000

2 000 000


1.00 2.00 3.00 4.00 5.00

AnnualAdditional

Fuel Cost(US$)

Figure 4-2:

Increase of 0.01Mach number (0.82 to 0.83)

LongA330

200

A340

300

A340

600


3 520 3 740 4 200


AdditionalFuel per Sector (kg)

1 400 1 870 1 150

Medium


2 550 2 400



795 945

Short


1 530

Annual Cycles 1 160


335



23/68

Point of contact:

[email protected]

AIRBUS PERFORMANCE

ENGINEERS PROGRAM (PEP) SOFTWARE PACKAGE:

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).



24/68

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.

4.2.3.2 Flight Level

Figure 4-3:

2000 ft below optimumflight level


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]

0

200 000

600 000

400 000

800 000

10 000 000


1.00 2.00 3.00 4.00 5.00

AnnualAdditional

Fuel Cost(US$)

LongA330

200

A340

300

A340

600


3 520 3 740 4 200



840 520 370

Medium


2 550 2 400



600 310

Short


1 530

Annual Cycles 1 160


360



25/68

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 4.2.3.5

below.

4.2.3.4 Aircraft performancedegradation

4.2.3.3 Flight Plan accuracy


Getting to Grips with Aircraft Performance

Monitoring Issue 1, January 2003

Point of contact:

[email protected]



26/68

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.

4.2.3.5 Fuel reserves

Figure 4-4:

Per additional1000 kg fuel reserve

0

50 000

150 000

100 000

200 000

250 000

300 000


1.00 2.00 3.00 4.00 5.00

AnnualAdditional

Fuel Cost(US$)

LongA330

200

A340

300

A340

600


3 520 3 740 4 200



210 270 265

Medium


2 550 2 400



155 155

Short


1 530

Annual Cycles 1 160

Additional

Fuel per Sector (kg)85



27/68

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

initiatives

,

Continuous monitoring to ensure

promotion of fuel and flight

efficiency measures

,

4.2.3.6 Airbus Operational Solutions

AIRBUS FUEL AND FLIGHT EFFICIENCY

CONSULTING SERVICES

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



28/68

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

improvement.

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:

customerservices.consulting

@airbus.com



29/68

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.

4.2.4.1 Fuel tankering




Point of contact:

[email protected]



30/68

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).

4.2.4.2 APU use




Figure 4-5:

Ten minutes less APU use per flight

0

10 000

20 000

50 000

40 000

30 000

60 000

70 000

80 000


1.00 2.00 3.00 4.00 5.00

AnnualFuel Saving

(US$)

LongA330

200

A340

300

A340

600


3 520 3 740 4 200


Fuel Saved

per Sector (kg)

35 50 50

Medium


2 550 2 400


Fuel Savedper Sector (kg)

35 50

Short


1 530

Annual Cycles 1 160


35



31/68

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.

4.2.4.3 Engine warm-up and cool-down periods


FCOM

Point of contact:

[email protected]

Table 4-1:

Overview of engine warm-up

and cool-down times(reference only)

WARMUP

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

COOLDOWN

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

ConditionProcedure

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



32/68

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.

4.2.4.4 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.



33/68

In any case, various factors need to

be considered before such a policy is

implemented:

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

manoeuvrability.

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).




FCOM Procedures PRO-SUP-93-20

Point of contact:

[email protected]

Figure 4-6:

Reduced engine taxiingfor 10 minutes per flight

0

50 000

100 000

150 000

200 000

250 000


1.00 2.00 3.00 4.00 5.00

AnnualFuel Saving

(US$)

LongA330

200

A340

300

A340

600


3 520 3 740 4 200



80 100 180

Medium


2 550 2 400



80 100

Short


1 530

Annual Cycles 1 160


80



34/68

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

procedure.

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.

4.2.4.5 Increased power operation at low aircraft speeds

4.2.4.6 Bleed Air Use

Point of contact:

[email protected]

Figure 4-7:

Take-off without bleed

0

2 000

6 000

4 000

8 000

10 000


1.00 2.00 3.00 4.00 5.00

AnnualFuel Saving

(US$)

LongA330

200

A340

300

A340

600

Average

Sector Length (nm)3 520 3 740 4 200



5 5 10

Medium


2 550 2 400



5 5

Short


1 530

Annual Cycles 1 160


5



35/68

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

economy.

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

considered.

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).




Getting to Grips with Aircraft Performance

Issue 1 January 2002

Point of contact:

Aircraft performance:

[email protected]



36/68

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.

4.2.4.7 Use of Electrical Power

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Figure 4-8:

Pack Flow selection(LO versus NORM)

LongA330

200

A340

300

A340

600


3 520 3 740 4 200



210 260 370

Medium


2 550 2 400



150 160

Short


1 530

Annual Cycles 1 160


90



37/68

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

performance.

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.

4.2.4.9 Departure direction

4.2.4.8 Take-Off Flap Setting

Point of contact:

[email protected]


Getting to Grips with Fuel EconomyIssue 4 October 2004

Getting to Grips with Aircraft PerformanceIssue 1 January 2002

Point of contact:

[email protected]

0

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Figure 4-9:

Take-off with CONF 1+Fcompared with CONF 3

LongA330

200

A340

300

A340

600


3 520 3 740 4 200



25 50 50

Medium


2 550 2 400



25 50

Short


1 530

Annual Cycles 1 160


25



38/68

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.

4.2.4.10 Take-off Acceleration Altitude




Point of contact:

[email protected]

0

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LongA330

200

A340

300

A340

600


3 520 3 740 4 200



10 20 25

Medium

Average

Sector Length (nm)

2 550 2 400



10 20

Short


1 530

Annual Cycles 1 160


10



39/68

A number of fuel saving measures

should be considered for the aircrafts

approach:

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

wear,

- Potential risk of damage to brakes

due to high brakes temperatures.

4.2.4.11 Approach Procedures

4.2.4.12 Landing Flap Configuration

Point of contact:

[email protected]

Point of contact:

[email protected]







Point of contact:

[email protected]


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.



40/68

Figure 4-11:

Landing in Conf 3instead of Conf FULL

Focus on Balancing Costs:_Sections 4.2.4.11 and 4.2.4.12 (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.


ISI 32.42.00002 Carbon Brakes Thermal Oxidation

Operational Procedures Impact

Point of contact:

(Brake System Engineering)

[email protected]

0

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1.00 2.00 3.00 4.00 5.00

AnnualFuel Saving

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LongA330

200

A340

300

A340

600

Avera

performance retention and fuel saving a330 a340

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