a320 performance retention and fuel savings v3

Airbus Flight OperationsDecember 2014

Getting to grips withPerformance retentionand fuel SavingA320 Family

#1 Scope p.003

#2 Introduction p.004

CONTENTS

Airbus Flight Operations002

#3 Industry Issues p.010

#4 Fuel saving opportunitiesp.017

#5 Summary & Conclusions p.056

Appendicesp.058

003Airbus Flight Operations

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 A320 Family aircraft. You will find brief discussions of the various initiatives that highlight both their pros and cons.

This is the third update of this document which was first published in October 2006.

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.

Dominique DESCHAMPSVice President Flight Operations and Training SupportCustomer Services

Gilles DE CEVINSVice President A320 Family Programme Customer Services

#1 ScopeThis document discusses the basic principles of fuel efficiency for in-service aircraft. It highlights measures that can reduce the fuel consumption of Airbus A320 family of aircraft. The documents objective is to contribute 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 sched-uling or passenger service level. Environmental issues are becoming increasingly important and these too have been outlined. References and points of contact within Airbus are provided throughout for those wishing to explore any item more fully.


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.


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 forces on an airframe

Thrust

Weight

Drag

Lift

Airbus Flight Operations 005

Figure 2-2 illustrates the long-term increasing trend of jet fuel price with its 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 typically the responsibility of the airlines fuel purchasing manager.The cost of fuel is the major contributor 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 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)2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 20130

0.5

1

1.5

2

2.5

3

3.5

0

20

40

60

80

100

120

140

US$per USGallon

US$ perBarrel


An aircraft of the A320 Family will typically consume between 3.5 and 8 tons of fuel (approximately 1200 to 2700 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 A320 aircraft in airline service on typical missions (described in the adjacent table) and how it varies with fuel price. A second table indicates the factors

that should be applied to determine the costs for other members of the A320 Family. 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 Cost Breakdown - 2004

Direct Operating Cost Breakdown - 2013

Crew 18% 24%

25%28%

Nav./ Landing

Maintenance

Fuel

Crew 14% 19%

19%

43%

Nav./ Landing

Maintenance

Fuel

Focus on sharklets:_

In December 2012, Airbus launched its new Sharklet large wingtip devices, specially designed to enhance the efficiency and payload-range performance of A320 Family aircraft.

The aerodynamic efficiency of an aircraft wing depends on its drag, which is made up of:

Profile drag-driven by surface area of the total airframe,

Wave drag-driven by transonic shocks, mostly on the wing,

Vortex drag-driven by lift creation.

The vortex drag component for transport aircraft flying at transonic speeds represents around 50% of the total aircraft drag. Since engine thrust is required to overcome this drag, it is clearly essential to achieve the lowest drag level possible in order to minimise its fuel burn. Sharklets are an enhancement of wing tip fences and further reduce the vortex drag by significantly changing the loading of the wing and effective span. They can dramatically reduce the fuel burn during cruise and offer significant improvements in climb performance.

Due to the reduced overall aircraft drag, a retrofitted aircraft needs lower engine thrust in cruise and in some cases, at take-off and during climb which reduces engine direct maintenance costs by extending the time between maintenance visits.

Offered as a linefit option since 2012, Sharklets have exceeded expectations and are already reducing fuel burn by 4% on longer sectors, corresponding to an annual CO2 reduction of around 900 tonnes per aircraft per year. In addition to the economic and environmental advantages of reduced fuel burn there are several operational benefits including an increased payload/range of up to 100 nm or 1.8 tonnes additional payload. Sharklets can also reduce the aircraft TOW (Take-Off Weight) limitation at many airports, especially those at high altitude or with obstacles. For these airports where the TOW is restricted by the second segment, Sharklets can further improve the payload by up to 3 tonnes. The improved lift also has a positive impact on direct engine maintenance cost, offering a saving of approximately 2% due to the reduced thrust at take-off.

As of today all A320 family aircraft delivered after MSN5514 are eligible for Production retrofit. These aircraft were delivered with the wing structure provisions for Sharklets and the retrofit is a straightforward task which can be managed by the airline or operator in around one day.

For older A319 and A320 variants Airbus offer the In-service retrofit which is applicable for aircraft built after MSN1200. As these aircraft were not originally designed for Sharklets they require an additional wing reinforcement kit. This prepares them for the increased static and fatigue loads and includes the new Sharklet attachment. The full modification takes around 10 days and will be managed by the MRO.


Figure 2-5:Annual fuel consumption per aircraft - A320

Data - Mission A

Annual cycles 1 800

Annual Flight Hours 2 700

Average sector length (Hours) 1.5

Data - Mission B

Annual cycles 1 500

Annual Flight Hours 3 000

Average sector length (Hours) 2

Data - Mission C

Annual cycles 1 100

Annual Flight (Hours) 3 300

Average sector length (Hours) 3

Annual Fuel Consumption

Average% Variation

from A320

A318 90%

A319 91%A320A320neo

100%85%

A321 111%

2.50 3.00 3.50 4.00 4.50 5.000

2 000 000

4 000 000

6 000 000

8 000 000

10 000 000

12 000 000

14 000 000

Fuel Price (US$ per US Gallon)

Annual Cost(US$)

Fuel efficiency is not new. However, f u e l s i n c r e a s i n g p r i c e a n d 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 born 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 the

development 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.

Table 2-2:Fuel consumption

equivalence

Table 2-1: Types of missions for A320 aircraft


Table 2-6:Other Getting to Grips with brochures

Direct influence on Fuel Economy Issue N Issue Date Available in

Getting to Grips with A330/A340 Family Performance Retention and Fuel Efficiency 1 Sep-11 English

Getting to Grips with A320 Family Performance Retention and Fuel savings 3 Sep-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, RussianGetting 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, RussianGetting to grips with RNP AR 2 Feb-09 English

Other titles

Getting to grips with ETOPS 5 Oct-98 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, ChineseGetting to grips with Approach and Landing Accidents Reduction 1 Oct-00

English, Chinese, Russian

Getting to Grips brochuresThe following titles are available and cover all Airbus types:

Important Note:_

None of the information contained in the Getting to Grips publications is intended to replace procedures or recommendations contained in the Flight Crew Operating Manual (FCOM), but rather to highlight the areas where maintenance, oper-ations and flight crews can con-tribute significantly to fuel savings.

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 managedby airlines IT administrator).

Point of contact: [email protected]


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 con-cerns. In simplistic terms, reducing fuel burn is the best way to reduce emis-sions, and hence the environmental impact, and fuel expenditure.

The market expects aircraft manufac-turers 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 air-craft 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 com-mitment drives aircraft performance 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 authori-ties and air navigation service providers (ANSPs) can all contribute by providing airlines with the means to use their air-craft in the most efficient way possible.

Optimum operational conditions can be compromised by Air Traffic Con-trol (ATC) requirements. For example, aircraft kept waiting on the taxiway,

Industry issues#3

Focus on A320neo:_

The A320neo (new engine option) is the new -efficient option offered by Airbus for the A320 Family that offers significant benefits for fuel consumption and environmental performance. These benefits are derived from the introduction of the latest engine and aerodynamic technologies. Together they deliver around 15% reductions in both fuel consumption and CO2 emissions compared with the previous generation of A320 Family aircraft. The neos main aerodynamic improvement is derived from the introduction of new wingtip devices called Sharklets. These devices can be retrofitted to most in-service A320 Family aircraft (see page 7 for further details).

The extra performance of the neo aircraft means that over 1100 tons of fuel saved per year per aircraft, (equivalent to the consumption of 1000 mid-size cars). The neo will also reduce CO2 emissions by more than 3600 tons a year.Neos NOx emissions are 50% below CAEP/6, and neo will be an airport-friendly aircraft: very quiet, up to 15 dB below ICAO chapter 4 limit.


restricted to non-optimum flight altitude 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 reform and 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.

Airbus 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 beneficial to review their operation requirements and capabilities with their local ATC authorities to both raise mutual awareness and identify opportunities for route and schedule optimization.

Industry issues

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 ATM services for a performance-based, benefit-driven approach to ATM modernization and gate-to-gate optimization, which is addressed through operational, technical, financial and human issues.

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

Specialists in Performance Based Navigation technics, providing Performance-Based Navigation techniques to enable aircraft to fly precisely along a pre-defined route by leveraging GPS-based onboard navigation systems to reduce aircraft separation and optimize arrival and departure procedures.

ATRiCS offering a Surface Management (SMAN) system that intelligently controls airfield ground lights, achieving a level of automated guidance and control, proven to reduce controller workload and improve common situational awareness for pilots.

Airbus ProSky is not only dedicated to support ing overall global Air Traffic Management modernization and harmonization, but also supporting EUROCONTROLs Single European Sky ATM Research (SESAR) and the Federal Aviation Administrations (FAA) Next Generation Air Transportation System (NextGen). SESAR and NextGen are two major development programmes for ATM launched in 2008. They aim by 2020 to reduce the environmental impact by 10% per flight, triple the air traffic capacity, halve ATM costs and improve safety. Airbus Upgrade Services team (e-Catalogue can be found on the Airbus World website) can provide all the necessary information regarding the embodiment of the service bulletins that can bring aircraft up to the standards required for operations in the evolving SESAR and NextGen environments.

FURTHER READINGIATA Guidance Material and Best Practices for Fuel and Environmental Management, 3rd Edition May 2008.

WEB SITESCleansky: www.cleansky.eu

SESAR: www.sesarju.eu

NextGen: www.faa/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]


Like many human activities, aviation and the air transport industry have an impact on the earths environment.The consequences of aircraft opera-tions that are typically of public con-cern are engine emissions and aircraft noise. A further source of concern is the use, handling and disposal of cer-tain materials that are encountered when maintaining aircraft (e.g. asbes-tos, 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 environ-ment; 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 when burning any mixture of air and a petroleum-based product. Jet turbine engines produce around 3.1 kg of CO2 for every kg of jet fuel burnt. At this point it is worth noting that today, aviation as a whole, accounts for only 2% of man-made CO2 emissions (this is forecast to reach 3% by 2050).

Focus on NOx:_

NOX, or nitrogen oxides, are an-other bi-product of burning fuel in an engine. Like CO2, they are believed to have a detrimental effect on the worlds environ-ment.In recognition of this, the airports of some nations adjust their landing charges according to the amount of NOX produced by the aircraft (as defined in the certifi-cation datasheet). Airbus aircraft have always been equipped with state-of-the-art engines offering among the lowest NOX levels in their class.

0

10

20

30

40

50

60

Energy Industry Roadtrafc

Aviation Other means oftransport

Othersources

%

Variation between studies

Figure 3-1:Human activities contribution to CO2 emissions. Sources: IPCC,

UNFCCC, IEA and DLR.


The Focus on CO2 text box with Fig-ure 3-1 illustrates that the aviation industrys consumption of fossil fuel and the consequent production of CO2 is relatively low. Notwithstanding this fact, 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.Though, the most prevalent green-house gas, CO2, spreads quickly in the atmosphere. It does not matter where or 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 READINGGetting to grips with Aircraft noise Issue 1, December 03

WEB SITESAirbus: 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 emis sions. The chargeable proportion of emissions is determined by an assessment of fuel efficiency. For the period 2013-2016 only emissions from flights within the EEA fall under the EU ETS. Exemptions for operators with low emissions have also been introduced. Note that the International Civil Aviation Organization (ICAO) is currently develop-ing a global market-based mechanism addressing international aviation emissions with a target of application by 2020.

Point of contact:Engine & Maintenance : [email protected]


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 natural gas, coal and biomass.

Jet fuels produced from alternative sources produce the same amount of CO2 when they are burnt as their traditional equiva lents. How-ever, the production of sustaina-ble biofuels (those produced from sustainable biomass sources, see next paragraph) contributes to CO2 reduction. Figures 3-2 and 3-3 illustrate the emissions produced during the lifecycle of fossil fuels and biofuels. All plants absorb CO2 as they grow. The CO2 absorbed 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 CO2 neutral.

sustainable biofuels are those created from biomass that does not compete with food production, use of fresh water, causes deforestation or reduces biodiversity. A variety of plants if man-aged correctly can be grown sustain-ably 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 CO2 sequestra-tion (capture), results in the release of more CO2 than the crude oil to fuel refining process. The natural gas to fuel process produces CO2 at com-parable 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 produc-tion of fuels from biofuel sources are understood. The challenges today are the sustainable commercialisation of these fuels and the need to continue 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 bio-fuel value chains in regions across the world working with the Round table on Sustainable Biofuels (RSB) to guarantee their sustainability-eco-nomic, social and environmental. Six such partnerships had been estab-lished 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 JET SOURCE FUELS _


Figure 3-2:Lifecycle emissions from fossil fuelsAt each stage in the distribution chain, CO2 is emitted through energy use by extraction, transport, etc. (Source: Beginners Guide to Aviation Biofuels, www.enviro.aero)

Figure 3-3:Lifecycle emissions from sustainable biofuelsCO2 emitted will be reabsorbed as the next generation 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]

Distribution at airports

Distribution at airports

Feedstock growth

FlightFlight

Transport

Transport

Processing

Extraction

Refining

Refining


FUEL SAVING OPPORTUNITIES

#4Efficient aircraft operations require the careful integration of many factors including regulatory restrictions, en-route and airport traffic control requirements, maintenance, crew scheduling and fuel costs.

Systematic, effective flight plan-ning and careful operation and maintenance 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 principles are reviewed. This is followed by discussions of specific procedures, 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 dollar values 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 _

4.3.3.1 General ...............................414.3.3.2 Flight Controls .....................414.3.3.3 Wing root fairing

panel seals ......................... 444.3.3.4 Moving surface seals ......... 454.3.3.5 Thrust Reverser Seals ........ 474.3.3.6 Landing Gear Doors .......... 474.3.3.7 Door and Window Seals .... 484.3.3.8 Paint Condition .................. 484.3.3.9 Aircraft exterior cleaning .... 494.3.4 Weight reduction ............. 504.3.4.1 Aircraft INTERIOR cleaning .514.3.4.2 Condensation .................... 524.3.4.3 Cabin Equipment ............... 524.3.4.4 Removal of galley

components ....................... 524.3.4.5 Safety Equipment ............... 534.3.4.5 Potable water upload

reduction ............................ 534.3.4.6 Waste Tank Emptying ........ 534.3.4.8 Other initiatives .................. 544.3.4.8 Air data system accuracy .. 55


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

4.2 Operational Initiatives ..... 194.2.1 Aircraft operations ........... 194.2.2 Cost index ........................ 194.2.3 Fuel economy ................... 204.2.3.1 Cruise speed...................... 204.2.3.2 Flight Level ......................... 224.2.3.3 Flight Plan accuracy ........... 224.2.3.4 Aircraft performance

degradation........................ 234.2.3.5 Fuel reserves ...................... 234.2.3.6 Airbus Operational

Solutions ............................ 244.2.4 Operational procedures .. 264.2.4.1 Fuel tankering .................... 264.2.4.2 APU use ............................. 264.2.4.3 Engine warm-up

and cool-down periods ...... 274.2.4.4 Single Engine Taxiing ......... 274.2.4.5 Increased power operation

at low aircraft speeds ......... 28

4.2.4.6 Bleed Air Use ..................... 294.2.4.7 Use of Electrical Power ...... 304.2.4.8 Take-off Flap Setting .......... 304.2.4.9 Departure direction ............ 314.2.4.10 Take-off Acceleration

Altitude............................... 314.2.4.11 Approach Procedures ........ 324.2.4.12 Landing Flap Configuration 324.2.4.13 Landing Lights ................... 344.2.4.14 Reverse Thrust ................... 344.2.4.15 Center of Gravity ................ 354.2.4.14 Take-off thrust reduction .... 35

4.3 Maintenance initiatives .. 364.3.1 Implications of dispatching

under MEL and CDL ........ 364.3.2 Propulsion Systems

Maintenance .................... 384.3.2.1 Trend monitoring ................ 394.3.2.2 Routine Engine

Maintenance ...................... 394.3.3 Airframe Maintenance ..... 40

Content

016 Airbus Flight Operations

Focus on Airline Fuel Efficiency Teams:_

As mentioned in the introduction, this document offers a starting point for airlines wishing to optimise their fuel consumption, emissions and operating costs.

Fuel saving initiatives are often the trade-offs. The fuel saved through the implementation of a given initiative usually needs to be assessed in the context of global airline cost breakdown and business model.

For example, the choice of flying at a non-optimum speed (e.g. flying faster to reduce crew costs or recover a delay) must balance fuel consumption against both crew cost and the cost of reduced aircraft availability (either for flights or maintenance).

These examples serve to illustrate the value of a multi-function team of airline personnel whose role is to weigh the relative costs and other pros and cons of a given 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 while assuring that all consequences are understood across the airlines organisation. Equally, given the challenges that 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 consumption

per flight phase

1h30

3% Taxi4% Descent

CruiseClimb

50%43%

2h00

3% Taxi3% Descent

Cruise

Climb

60%

34%

3h00

2% Taxi2% Descent

Cruise

Climb

72%

24%


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 appropriate parameters 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 the optimization of airspeed and altitude. However, these two conditions may be difficult to achieve in an opera-tional environment. Usually a trade-off must be made between fuel burn and flight time on one hand and ATC con-straints on the other. 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 a high 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), conversely 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 assess-ments of all relevant 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 condi-tions 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 initiatives discussed

Reference documents:Getting to Grips with the Cost Index Issue 2 May 1998


4.2.1 Aircraft operations


The following factors affect 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 with the 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 23.

Realistic fuel consumption predictions can be obtained using Airbus Perfor-mance Engineering Program (PEP) software (refer to the following text 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 0.79 instead of 0.78).

4.2.3 Fuel economy

4.2.3.1 Cruise speed

Reference documents:Getting to Grips with Fuel Economy

Issue 4 October 2004


2.50 3.00 3.50 4.00 4.50 5.000

50 000

100 000

150 000

200 000


AnnualAdditionalCost (US$)

Data - Mission A

Annual cycles 1 800Annual Flight Hours 2 700Average sector length (Hours) 1.5Additional fuel per sector (KGs) 27

Data - Mission B

Annual cycles 1 500Annual Flight Hours 3 000Average sector length (Hours) 2Additional fuel per sector (KGs) 46

Data - Mission C


Figure 4-2:Increase of 0.01 Mach number (0.78 to 0.79)


Issue 4 October 2004Getting to Grips with Aircraft Performance

Issue 1 January 2002



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 package applicable to the suppliers products only. As such, Airbus PEP software provides unrivalled degree of precision in the optimization of efficient operations of its aircraft.

The Airbus PEP is comprised 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) calculation gives the maximum take-off (landing) weight and associated speeds for a given aircraft, runway and airport 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 characteristics, 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 studies before opening operations on a route.

In Flight Performance (IFP): computes general aircraft in-flight performance 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 statistical approach, 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 on operational constraints (Noise abatement procedures, standard instrument departure, etc.) (Not available for A300).


Modern commercial jet engines, includ-ing those fitted to Airbus A320 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 Per-formance (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 when-ever possible. Nonetheless, the Flight Plan should always be an accurate representation of the actual flight being undertaken and include all known ATC constraints.

In terms of aircraft operation, an accu-rate, Computerized Flight Plan (CFP) is one of the most important means of reducing fuel burn.

As is the case with most computer systems, the accuracy of the data pro-vided to a CFP system will influence the accuracy of the CFPs it produces. However, the nature of some of the parameters can bring a certain degree of inaccuracy.

For example:

Weather conditions: particularly temperatures and wind strengths/directions.

Fuel specification (lower heating value): defines the heat capacity of the fuel. Engine thrust depends on the amount of heat energy coming

from the fuel it is burning. The aircraft database may contain a standard or average value that may not corre-spond to the actual fuel used. A fuel analysis or data from the fuel provider can provide the necessary clarifica-tion.

Inclusion of actual ATC constraints. Up-to-date aircraft weight: aircraft

weighing is a scheduled maintenance action and the latest data should be systematically transferred to the CFP system.

Payload estimation: assessment of passenger baggage and cargo variations with route and season.

Aircraft performance degradation: refer to following section.

Fuel reserves: refer to section 4.2.3.5 below.

4.2.3.2 Flight Level

4.2.3.3 Flight Plan accuracy

2.50 3.00 3.50 4.00 4.50 5.000

50 000

100 000

150 000

200 000

250 000

200 000



Data - Mission A


Data - Mission B


Data - Mission C


Figure 4-3:2000 ft below optimum flight level


Issue 4 - October 2004Getting to Grips with Aircraft Performance

Issue 1 - January 2002FCOM Performance PER-CRZ-ALT-10



With time the airframe and engine deteriorate such that the aircraft requires more fuel for a given mission. These deteriorations can be partially or fully recovered through scheduled maintenance actions. Deterioration will begin from the moment the air-craft enters service and the rate will be influenced by the utilization and operation of the aircraft.

The Aircraft Performance Monitoring (APM) module of the Airbus Perfor-mance Engineering Program (PEP) software package (see section on page 21 for more information) allows calculation of aircraft degradation over time. It can also be used as a means

of triggering maintenance actions to recover some of the degradation.

The implementation of an Aircraft Per-formance Monitoring program requires the processing of data through the APM software. The required data, known as cruise points, are auto-matically recorded by the aircraft. Depending on the aircrafts configu-ration, the transfer of these data can be achieved via either printouts from the cockpit printer, a PCMCIA card or diskette, or via the ACARS system.

The performance degradation for each individual aircraft is an important parameter. Accurate interpretation of this factor will enable the fuel usage

predictions of the Flight Management System (FMS) to better match those of the CFP system.

Knowledge of performance levels can also facilitate an operators dis-cussions 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 24).

Part of any extra fuel transported to a destination is just burnt off in carrying itself. It is not uncommon for flight crew to uplift additional discretionary fuel beyond 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 predictions 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 restrictions (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 appropri-ate.

4.2.3.4 Aircraft performance degradation

4.2.3.5 Fuel reserves

2.50 3.00 3.50 4.00 4.50 5.000

50 000

100 000

150 000

200 000



Figure 4-4:Additional 1000 kg

per fuel reserve

Reference documents:Getting to Grips with Aircraft Performance Monitoring Issue 1, January 2003


Misson A

Misson B

Misson C

Data - Mission A


Data - Mission B


Data - Mission C



1st Phase 2nd Phase

Diagnosis Monitoring

Data & process analysis,

Indentication of initiatives,

Dene areas of improvement & establish recommendations, quick wins and KPIs

,

Operational analysis per ight phase

,

Follow, control & report the implementation of initiatives

,

Ensure correct use of adoptedinitiatives

,

Continuous monitoring to ensure promotion of fuel and ight efciency 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 identifi-cation 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

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 which will provide regular reports with information


Aircraft operations fuel optimization action overview:_

The following actions have been described in the preceding sections and should be implemented to ensure a systematic reduction in fuel consumption 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 performance factors to be used by Flight Management System (FMS) and CFP system 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 and optimize for each flight,

Minimize discretionary fuel reserves and include all reserves in CFP.

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 recommendations and 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 to providing 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


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. On the other hand, there are occasions when it is, in fact, more cost effective to carry more fuel. This can occur when the price of fuel at the destination is significantly 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.Graphs in the FCOM and 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.

Ground power and air are usually sig-nificantly cheaper per hour than the APU (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 availability and use of ground equipment for the provision of both air and electrical power should be re-evaluated at all destinations and the possibility of obtaining and operating additional ground equipment where

necessary should not be dismissed without evaluation.On ground, the APU burns 95 to 100 kg/h fuel if used only for electrical power and 120 to 130 kg/h if used for both electrical power and air condition-ing (depending on APU manufacturer).The following example illustrates the cost of jet fuel for 5 minutes of APU use. It is worth noting that in addition to the fuel saved by this initiative, CO2 emissions would also be reduced (6 to 7 kg of CO2 saved per minute of APU operation).

4.2.4.1 Fuel tankering

4.2.4.2 APU use







2.50 3.00 3.50 4.00 4.50 5.000

10 000

20 000

40 000

30 000

50 000


AnnualSaving (US$)

Data - Mission A

Annual cycles 1 800Annual Flight Hours 2 700Average sector length Hours 1.5Fuel economy per sector (KGs) 11

Data - Mission B

Annual cycles 1 500Annual Flight Hours 3 000Average sector length (Hours) 2Fuel economy per sector (KGs) 11

Data - Mission C


Figure 4-5:Five minutes less APU use per flight


An engine from on an A320 Family aircraft weighs approximately 1 ton and consequently it takes time for all components to reach their operating temperature. Furthermore the various

components will expand and contract with temperature at different rates.

Minimum warm-up and cool-down periods 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 to losses in efficiency and increased fuel consumption.

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 beneficial 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 may be excessive with associated possi-ble FOD or jet blast damage.

For taxi out, it is also recom-mended keeping the APU running for second engine start (to avoid X BLEED start with thrust increase on supplying engine), which reduces the fuel economy by 150 kg / hr. Last but not least, late detection of some failure is also to be con-sidered. This is mainly applica-ble 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 and shoulders in bad condition) may pre-vent single engine taxi-in.

4.2.4.3 Engine warm-up and cool-down periods

4.2.4.4 Single Engine Taxiing

Reference documents:FCOM Volume 3


Table 4-6:Overview of engine warm-up and cool-down times (reference only)

WARMUP

Standard Engine StartAt or near idle for at least 2 minutes before advancing the thrust lever to high power.

Standard Operating Procedure PRO-NOR-SOP-09

Supplementary Techniques PRO-SUP-93-20

Engine Start after prolonged shutdown period (more than 2 hours - IAE or PW engine only)

At or near idle for at least 5 minutes before advancing the thrust lever to high power (taxi time at idle may be included in the warm-up period).



COOLDOWN

Engine Shutdown following high thrust operation (such as maximum reverse thrust during landing)

At idle for 3 minutes prior to shutdown (can include operating time at idle, such as taxiing).



ConditionProcedure

(for reference only this document does not replace or supercede the FCOM)

FCOM Reference

Focus on Flight Crew Documentation for Fuel Efficiency:_

A clear airline demand for procedural documentation to support the deployment in daily operations of the fuel saving techniques outlined in this document has now been met with the introduction of the Green Operating Procedures (GOPs).

They can be found in the supplementary procedures sections of the Flight Crew Operating Manuals (FCOM PRO-SUP-93) and Flight Crew Training Manuals (FCTM SI-100).

The GOPs provide detailed guidance to flight crews for procedures that can contribute to fuel savings. The guidance includes advice on the factors that should be considered before using a specific procedure but it remains the responsibility of each airline to adapt these procedures to their operations.

As is the case with all flight crew documentation the GOPs will evolve as new technologies, environmental changes, regulation evolutions, new fuel saving opportunities, etc. are introduced.


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 rc ra f t manoeuvrability.

I nc reased th rus t se t t i ng 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 CO2 emissions in and around the airport terminal area. Single engine

taxi can reduce CO2 emissions by around 17kgs per minute (refer to the text box Focus on CO2 on page 12 for additional information).


Issue 4 October 2004FCOM Procedures PRO-SUP-93-20


2.50 3.00 3.50 4.00 4.50 5.000

50 000

100 000

150 000

200 000


AnnualSaving (US$)

Data - Mission A

Annual cycles 1 800Annual Flight Hours 2 700Average sector length (Hours) 1.5Fuel economy per sector (KGs) 58

Data - Mission B


Data - Mission C


Figure 4-7:Single engine taxiing for 10 minutes per flight

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 or block 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.

4.2.4.5 Increased power operation at low aircraft speeds



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 2 Packs 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 situations where the cabin is hot, and the requested temperature is lower: Having 2 Packs running will burn

more fuel but improve the cooling efficiency

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 temperature, installed/activated IFE/lights, other heat loads like galley etc., window 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 fuel burn 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, the fuel saving expected from single pack operation highly depends on environmental conditions (OAT, desired cabin temperature, pas-sengers 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

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, compressed air requires more work to be done by the engines or APU and to achieve this, more fuel must be burnt.

4.2.4.6 Bleed Air Use

2.50 3.00 3.50 4.00 4.50 5.000

2 000

4 000

8 000

6 000

10 000


AnnualSaving (US$)

Data - Mission A


Data - Mission B


Data - Mission C


Figure 4-8:Take-off without bleed

Reference documents:Getting to Grips with Fuel Economy Issue 4 October 2004Getting to Grips with Aircraft Performance Issue 1 January 2002

Point of contact: Aircraft performance: [email protected]


initial climb). When assessing this option, the actual cabin temperature and its effect on passenger comfort should be considered.

The economic mode (select LO or ECON Pack Flow) reduces pack flow rate by 25% (with an equivalent reduc-

tion in the amount of air taken from the engines). This mode can be used on flights with reduced load factors: less than 115 passengers on A318/A319/A320 and less than 140 passengers on A321. However, single pack operation is generally 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.

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, max-imizing 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.

4.2.4.7 Use of Electrical Power

4.2.4.8 Take-Off Flap Setting

2.50 3.00 3.50 4.00 4.50 5.000

10 000

20 000

30 000

40 000


AnnualSaving (US$)

Data - Mission A


Data - Mission B


Data - Mission C


Figure 4-9:Take-off with CONF 1F compared with CONF 3






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 acceleration altitude. Once at accel-eration 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 optimum 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 acceler-ation altitude.

Ideally departure should be in direction of the flight. Most airports have Stand-ard 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.

4.2.4.10 Take-off Acceleration Altitude

4.2.4.9 Departure direction

Reference documents:Getting to Grips with Fuel Economy Issue 4 October 2004Getting to Grips with Aircraft Performance Issue 1 January 2002



2.50 3.00 3.50 4.00 4.50 5.000

10 000

20 000

30 000

40 000


AnnualSaving (US$)

Data - Mission A


Data - Mission B


Data - Mission C


Figure 4-10:Using 800 ft acceleration altitude

instead of 1500 ft


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 accuracy. 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 150 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 is to 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 will increase 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









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 Crew Op-erating Manual) recommends the use of the FULL configuration for all landings. Nonetheless, where runway length and conditions are favorable configuration 3 May be considered.


2.50 3.00 3.50 4.00 4.50 5.00

10 000

20 000

30 000


AnnualSaving (US$)

0

Data - Mission A


Data - Mission B


Data - Mission C


Figure 4-11:Landing in Conf 3

instead 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 will be an increase in landing distance. An increase in landing distance could mean that the normal runway exit cannot be used and possibly increase the block time for the flight. For many airlines an increase in block time will mean 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 (brakes must be allowed to cool down to acceptable levels before departure) and/or increased thermal oxidation of the brake carbon (leading to possible unscheduled, premature brake removal and even brake disc rupture). Increased brake and tire wear would be expected to increase the per landing cost of these components and, once again, the additional cost must 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]


Using idle reverse on landing instead of full reverse will reduce fuel consump-tion and may benefit the engine.

However, the aircrafts kinetic energy at landing must still be dissipated. It may be possible to achieve this over a longer landing distance and thereby limit any increases in brake and tire wear this procedure implies but, in all cases, the operational and economic aspects highlighted in the previous section (Landing Flap Configuration) should be considered for each landing (refer to Focus on Balancing Costs text box page 33 for further details).

4.2.4.14 Reverse Thrust


Reference documents:Getting to Grips with Aircraft Performance

Issue 1 January 2002Important Note:_

In order to maximize safe-ty margins the Airbus FCOM (Flight Crew Operating Man-ual) recommends the use of maximum thrust reverse for all landings. Nonetheless, where runway length and conditions are favorable reverse idle may be considered.

2.50 3.00 3.50 4.00 4.50 5.000

10 000

20 000

40 000

30 000

50 000


AnnualSaving (US$)

Figure 4-12:Using reverse idle

instead of reverse max

The effect of landing lights on the fuel consumption during approach is negligible:

Their drag is negligible with regard to the drag of the aircraft with slats/flaps extended and landing gear down.

Their electrical consumption during the few minutes of the approach is also negligible.

4.2.4.13 Landing Lights

Misson A

Misson B

Misson C

Data - Mission A


Data - Mission B


Data - Mission C



All commercial aircraft must have their centre of gravity (CG) forward of their centre of lift in order to remain stable in flight. Fuel and payload distribution determines the CG position and the allowable range of CG positions is defined in the Flight Manual. On many

aircraft a CG position towards the rear of the allowable range will allow a more aerodynamic configuration. However, for aircraft of the A320 Family CG position has a negligible effect on fuel consumption.

Take-off thrust reduction is a tech-nique to optimize the thrust produced at take-off. The thrust produced cor-responds to the aircraft weight and climatic conditions at take-off. It offers an alternative to max. take-off thrust.

A reduction from max. take-off thrust during the take-off phase will reduce fuel consumption. However, reduced thrust brings with it reduced climb per-formance. Consequently the aircraft requires longer time to achieve its opti-mum climb and cruise configurations.

As a result, the use of reduced thrust, either by de-rate or flex (flexible) take-off techniques will increase overall fuel consumption.

However, even in todays environment of elevated fuel prices, this is more than compensated by the reduction in engine wear and degradation that lead to increased fuel consumption and maintenance costs (refer to section 4.3.2, Propulsion Systems Maintenance, page 38 for further details).

4.2.4.15 Center of Gravity

4.2.4.16 Take-off thrust reduction

AIRCRAFT PROCEDURE FUEL OPTIMIZATION ACTION OVERVIEW

The following actions for operational cost reduction have been described in the preceding sections:

Fuel tankering,

Use of the APU on ground,

Adherence to minimum engine warm-up and cool-down periods,

Single engine taxi,

Reduced engine power operations on ground,

Reduction of bleed air use,

Take-off flap setting,

Departure route assessment,

Reduced take-off acceleration altitude,

Review of approach procedures,

Landing flap configuration,

Reduction of thrust reverse use on landing,

Reduced take-off thrust.

To conclude this section we review a couple of items that may be erroneously associated with fuel efficiency.


Operators are provided with a Master Minimum Equipment List (MMEL) that is the basis for their MEL (Minimum Equipment List). The MEL is a valuable tool for optimizing dispatch reliability because it defines the conditions under which the aircraft may be dispatched with specified equipment inoperative.The conditions include the period dur-ing which the aircraft can be operated with the system inoperative and, in some cases, requirements for addi-tional fuel load.The Configuration Deviation List (CDL) in the Flight Manual (FM) also allows the aircraft to be dispatched with specified components not fitted. All components must be re-installed at the earliest maintenance opportunity (nominally within 1 week, subject to

local airworthiness authority approval).

For items whose loss or failure will bring a fuel consumption penalty, it is beneficial to make special efforts to replace them as soon as possible.

The tables on the following page indi-cate the MMEL and CDL items that will have a noticeable negative impact on fuel cost. They indicate the penalty for typical sector lengths and also the cost of the additional fuel (calculated at a fixed price of US$3.00 per US Gallon) that would be burnt during the nominal period allowed for repairs (10 days for MMEL item and 1 week for a CDL item). The typical missions, used throughout this document, are defined in the adjacent table.

In this section, the value of careful aircraft maintenance is considered. Proactive measures include regular inspections and repair, when necessary. Before that is reviewed, the following section covers a document that allows aircraft opera-tions when specified components have failed. Its content is usually considered as being the responsibility of both the operational and maintenance domains.

4.3 MAINTENANCE INITIATIVES _

4.3.1 Implications of dispatching under MEL and CDL

Data - Mission A

Annual cycles 1 800Annual Flight Hours 2 700Average sector length (Hours) 1.5

Data - Mission B

Annual cycles 1 500Annual Flight Hours 3 000Average sector length (Hours) 2

Data - Mission C

Annual cycles 1 100Annual Flight Hours 3 300Average sector length (Hours) 3

Points of contact:MMEL and CDL (FM) content:

[email protected]

Aircraft performance: [email protected]


System/Component MMEL Condition

Maximum additional fuel required per sector - Kilograms

(Cost of additional fuel over 10 days - at US$3.00 / US gallon)

Mission A(1.5 hours)

Mission B

a320 performance retention and fuel savings v3

Documents

fuel prices

fuel bill

a320 family aircraft

aircraft manufacturers

inservice aircraft

commercial aircraft

scopethis document

outside airbus