Flight Operations Support & Line Assistance
getting to grips with
fuel economy
Issue 3 - July 2004
Flight Operations Support & Line Assistance
Customer Services
1, rond-point Maurice Bellonte, BP 33
31707 BLAGNAC Cedex FRANCE
Telephone (+33) 5 61 93 33 33
Telefax (+33) 5 61 93 29 68
Telex AIRBU 530526F
SITA TLSBI7X
Getting to grips with Fuel Economy Table of contents
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TABLE OF CONTENTS
TABLE OF CONTENTS 1
1. SUMMARY 4
2. PREAMBLE 5
3. INTRODUCTION 6
4. PRE-FLIGHT PROCEDURES 7
4.1 CENTER OF GRAVITY POSITION 8
4.1.1 INTRODUCTION 8
4.1.2 AUTOMATIC CENTER OF GRAVITY MANAGEMENT 8
4.1.3 INFLUENCE ON FUEL CONSUMPTION 9
4.2 TAKEOFF WEIGHT 11
4.2.1 INTRODUCTION 11
4.2.2 OVERLOAD EFFECT 11
4.2.3 AIRCRAFT OPERATING WEIGHT 12
4.2.4 PAYLOAD 13
4.2.5 EMBARKED FUEL 13
4.3 FLIGHT PLANNING 14
4.4 TAXIING 17
4.5 FUEL FOR TRANSPORTATION 19
4.6 AUXILIARY POWER UNIT 21
4.7 AERODYNAMIC DETERIORATION 23
5. IN FLIGHT PROCEDURES 24
5.1 Take-off and Initial Climb 25
5.1.1 INTRODUCTION 25
5.1.2 BLEEDS 25
5.1.3 CONFIGURATION 25
5.1.4 SPEEDS 26
5.1.5 FLEX THRUST 26
5.1.6 NOISE FLIGHT PATHS 26
5.1.7 COURSE REVERSAL 26
1 - Summary Getting to Grips with Fuel economy
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5.2 CLIMB 27
5.2.1 INTRODUCTION 27
5.2.2 THE EFFECT OF CLIMB TECHNIQUE ON FUEL BURN 28
5.2.3 CORRELATION OF FUEL BURN & TIME WITH CLIMB TECHNIQUE 31
5.2.4 CLIMB TECHNIQUE COMPARISON TABLES 34
5.2.5 DERATED CLIMB 35
5.3 CRUISE 36
5.3.1 INTRODUCTION 36
5.3.2 CRUISE ALTITUDE OPTIMISATION 37
5.3.3 CRUISE SPEED OPTIMISATION 47
5.3.4 WIND INFLUENCE 49
5.3.5 MANAGED MODE 52
5.3.6 EFFECT OF SPEED INCREASE ON MANAGED MODE 56
5.4 DESCENT 57
5.4.1 INTRODUCTION 57
5.4.2 THE EFFECT OF DESCENT TECHNIQUES ON FUEL BURN 58
5.4.3 MANAGED MODE DESCENT 60
5.4.4 EARLY DESCENT 60
5.5 HOLDING 62
5.5.1 INTRODUCTION 62
5.5.2 VARIOUS CONFIGURATION / SPEED COMBINATIONS 63
5.5.3 LINEAR HOLDING 68
5.6 APPROACH 70
5.6.1 FLIGHT PATH PRIOR TO GLIDE SLOPE INTERCEPTION 70
5.6.2 LANDING GEAR EXTENSION 70
6. DETAILED SUMMARY 71
6.1 INTRODUCTION 71
6.2 General guidelines 71
6.2.1 PRE-FLIGHT PROCEDURES 71
6.2.2 TAKE-FF AND INITIAL CLIMB 72
6.2.3 CLIMB 72
6.2.4 CRUISE 72
6.2.5 DESCENT 72
6.2.6 HOLDING 73
6.2.7 APPROACH 73
6.3 FUEL SAVINGS 73
6.4 ECONOMIC BENEFITS 75
7. CONCLUSIONS 76
Getting to grips with Fuel Economy Table of contents
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8. APPENDICES 77
APPENDIX A (Climb Charts) 78
APPENDIX B (Descent Charts) 80
1 - Summary Getting to Grips with Fuel economy
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1. SUMMARY
Fuel Consumption is a major cost to any airline, and airlines need to focus
their attention on this in order to maintain their profitability. This brochure looks
at all the significant operating variables that affect fuel economy for the current
Airbus range of aircraft.
This brochure shows that there are many factors that affect fuel consumption
and that the potential gains and losses are huge. Most of these factors are directly
controlled by the airlines own employees (flight crew, operations/dispatch,
maintenance, etc.).
It can be also seen that what is good for one type of aircraft is not
necessarily good for another, and that certain conceptions regarding best
techniques for fuel economy are wrong.
Finally for a fuel and cost economic airline, the following are the main
features:
• Good flight planning based on good data.
• Correct aircraft loading (fuel weight and CG).
• An aerodynamically clean aircraft.
• Optimal use of systems (APU, Bleed, Flaps/Slats, Gear, etc).
• Flight Procedures using speeds and altitudes appropriate to the
companies economic priorities.
• Use of the FMGS in the managed mode.
• Use of performance factors in flight planning and in the FMGS derived
from an ongoing aircraft performance monitoring program.
Getting to grips with Fuel Economy 2 - Preamble
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2. PREAMBLE
The very competitive and deregulated aviation market as well as the fear of
a fuel price rise have made airlines understand how important it is to work on the
fuel consumption of their fleet. Indeed airlines try to reduce their operational
costs in every facet of their business, and fuel conservation has become one of
the major preoccupations for all airlines, as well as aircraft manufacturers. That’s
why all ways and means to reduce fuel costs have to be envisaged, safety being
　
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