al Average sector length (Hours):  2 
nu Additional fuel per sector (KGs):  58 
$20,000 An Data - Mission C 
Annual cycles:  1100 
$0  Annual Flight Hours:  3300 
$1.50 $1.70 $1.90  Average sector length (Hours): $2.10 $2.30 $2.50  3 
Additional fuel per sector (KGs):  58 

Figure 3-7 Single engine taxiing for 10 minutes per flight
3.2.4.5. HIGH POWER OPERATION AT LOW AIRCRAFT SPEEDS
Operating an engine at high 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 aerofoil 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 24),

.  
Avoiding high thrust excursions during taxi,

.  
Progressive thrust increase with ground speed during take-off procedure.

Point of contact:
fltops.perfo@airbus.com

3.2.4.6. BLEED AIR USE
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.
Data - Mission A
Annual cycles: 1800
$40,000 Annual Flight Hours: 2700
$35,000
Average sector length (Hours): 1.5 $30,000
Additional fuel per sector (KGs): 3 Data - Mission B
$25,000 Annual cycles: 1500
$20,000
Annual Flight Hours: 3000 $15,000
Average sector length (Hours): 2 Additional fuel per sector (KGs): 3$10,000
Data - Mission C
$5,000
Annual cycles: 1100 $0
Annual Flight Hours: 3300 Average sector length (Hours): 3 Additional fuel per sector (KGs): 3
Figure 3-8
Take-off with bleed

Take-off without bleed can reduce fuel consumption or allow take-off thrust to be optimized. When assessing this option, the actual cabin temperature and its effect on passenger comfort should be considered. The packs would be selected ON during the initial climb.
The economic mode (select “LO” or “ECON” Pack Flow) reduces pack flow rate by 25% (with an equivalent reduction in the amount of air taken from the engines). This mode can be used on flights with reduced load factors and may be considered with higher load factors. In either case temperature variations within the cabin may develop but these can be minimized by cycling between economic and normal modes during the flight. Single pack operation is generally not recommended.
　
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