Landing in CONF 3 – Use of reversers

Report
Presented by:
Hélène REBEL
Head of A330/A340 Operational Standard
Landing in CONF 3 – Use of reversers
General considerations
Airbus Flight Crew Operating Manuals recommendation
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
CONF FULL – Maximum Reverse thrust
Maximize safety margins
Landing in CONF 3 - Use of reversers
April 2007
Page 2
General considerations
• For economics, airlines could envisage:
Approach
in CONF 3
Idle or no reverse thrust at landing
 All operational and economics consequences have to be
considered.
• Above all, the first considerations must be:
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
The
aircraft landing weight
The runway length
The braking means
The runway surface conditions
The tailwind
Autoland not certified in CONF 3 (CONF 15/20) for A300/A310
aircraft family
Landing in CONF 3 - Use of reversers
April 2007
Page 3
Content
 General considerations
 Fuel economy estimation
 Additional considerations:
 Other operating cost considerations
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
 Operational consequences
 Pro and Cons: Summary
 Conclusion
Landing in CONF 3 - Use of reversers
April 2007
Page 4
Fuel economy estimation
• Depends on several parameters as:
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
–
–
–
–
–
–
–
Aircraft / Engine type
Aircraft weight during the approach
Approach speed
Autobrake selection
Airport elevation
The ISA conditions
…

Landing in CONF 3 - Use of reversers
Fuel economy estimation
April 2007
Page 5
Fuel economy estimation
• Simulation hypothesis
elevation: Sea Level
ISA conditions
Approach speed VLS + 5 knots
Autobrake LO
2 aircraft weights: light and heavy weights
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Airport
Landing in CONF 3 - Use of reversers
April 2007
Page 6
Fuel economy estimation
• Simulation hypothesis – Cont’d
LANDING AT REV MAX
1500 ft:
REV MAX
REV IDLE
70 kts *
S/F configuration for
landing: CONF 3 or FULL
0 kt
* 85 kts for Wide Body aircraft
LANDING AT REV IDLE
1500 ft:
REV IDLE
0 kt
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
S/F configuration for
landing: CONF 3 or FULL
LANDING WITH NO REV
1500 ft:
S/F configuration for
landing: CONF 3 or FULL
Landing in CONF 3 - Use of reversers
IDLE THRUST
0 kt
April 2007
Page 7
Fuel economy estimation
• RESULTS
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Average fuel consumption increase in kg
between
REV MAX
and
REV IDLE
REV IDLE
and
No REV
CONF FULL
and
CONF 3
CONF FULL / REV MAX
and
CONF 3 / REV IDLE
A320
family
10 to 15
2
10 to 15
15 to 30
15 to 20
2
5 to 15
20 to 40
A330
family
25 to 45
5
10 to 15
40 to 55
40 to 60
5
10 to 25
60 to 75
A340200/300
35
5
15
50
40
5
15 to 20
60
A340500/600
65
10
10
75
85 to 90
15
5
95
30 to 40
3
15 to 25
50
Light weight
50 to 65
3
15 to 30
80
Heavy weight
A300
family
Landing in CONF 3 - Use of reversers
April 2007
Page 8
Content
 General considerations
 Fuel economy estimation
 Additional considerations:
 Other operating cost considerations
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
 Operational consequences
 Pro and Cons: Summary
 Conclusion
Landing in CONF 3 - Use of reversers
April 2007
Page 9
Other operating cost considerations
• Thrust Reversers
reversers thrust  Reduction of FOD risk and
associated maintenance
Lower
Maintenance Cost (DMC) is
mainly affected by thermal cycling
or age of the materials
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Direct
Deployment
of reversers has a minor impact in DMC
 No advantage to do a landing without reversers
Landing in CONF 3 - Use of reversers
April 2007
Page 10
Other operating costs consideration
• Tires
Tire
wear is affected by several parameters which are mainly:
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
– Loads
– Pressure
– Ground surface roughness
– Temperature
– Aircraft roll
Touch down:
Braking:
20% to 30%
20% to 40%
Straight line rolling:
Maneuvering :
20% to 30%
10% to 20%
 If basic braking recommendations are applied:
Overall tire DMC impact is likely to be small
Landing in CONF 3 - Use of reversers
April 2007
Page 11
Other operating costs consideration
• Brakes
Example of brake energy difference depending on the
approach speed and the use of reverse : A300-622
Autobrake LO
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Braking Energy
(106 J / wheel)
REV MAX
REV IDLE
No REV
CONF FULL
(30/40)
9
18
14
27
18
33
CONF 3
(15/20)
10
20
15
33
20
40
Slight
increase
Multiplied by 1.5
Multiplied by 2
 Increasing the approach speed and/or using Rev Idle will
lead higher brake temperature
Landing in CONF 3 - Use of reversers
April 2007
Page 12
Other operating costs consideration
• Brakes
In
general carbon brake life is affected by
– Carbon brake wear
– Carbon brake oxidation
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
• Catalytic oxidation
• Thermal oxidation
Landing in CONF 3 - Use of reversers
April 2007
Page 13
Other operating costs consideration
• Brakes: Effect on Carbon Brake wear
Carbon
brake wear is mainly affected by:
– Number of brake applications
 Not linked to the approach conf or the use of
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
reversers
Landing in CONF 3 - Use of reversers
April 2007
Page 14
Other operating costs consideration
• Brakes: Effect on Carbon Brake wear
Carbon
brake wear is mainly affected by:
– The brake temperature
Messier - Bugatti
Wear
rate
Honeywell-ALS
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BF Goodrich
0
80
150
250
315
500
Indicated temperatureC
 Optimum brake temperature range is still
compatible with such operations
Landing in CONF 3 - Use of reversers
April 2007
Page 15
Other operating costs consideration
• Brakes: Effect on Carbon Brake thermal oxidation
Thermal
oxidation is temperature and time related:
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– Repetitive high temperature occurrences
– Long duration of carbon exposure to high temperature
Thermal
oxidation leads to severe brake damage (disk
rupture, etc) or loss in braking efficiency
Premature brakes removal
Landing in CONF 3 - Use of reversers
April 2007
Page 16
Other operating costs consideration
• Brakes: Effect on Carbon Brake thermal oxidation
approach speed  Higher brake energy is
necessary to stop the aircraft
Increased
Idle instead of Rev max  Poor sharing of brake energy
between reversers and brakes
Rev
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
 Depending on flight crew braking management,
brake oxidation could be drastically increased
Landing in CONF 3 - Use of reversers
April 2007
Page 17
Other operating costs consideration
• Brakes: General guidelines
To
minimize negative effect on the brakes the following could
be considered:
– Restrict the application of such procedure to runway where
Autobrake LO can be used and is actually used.
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
– Do not override the autobrake to shorten the landing distance.
– Respect basic Airbus SOP recommendations:
• Delay the brake fans selection for 5 minutes (or at the gate) if
turn-around permits.
• Avoid prolonged parking brake application on hot brakes.
Landing in CONF 3 - Use of reversers
April 2007
Page 18
Content
 General considerations
 Fuel economy estimation
 Additional considerations:
 Other operating cost considerations
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
 Operational consequences
 Pro and Cons: Summary
 Conclusion
Landing in CONF 3 - Use of reversers
April 2007
Page 19
Operational consequences
• Approach in CONF 3:
Higher
pitch attitude
 May increase the number of alert triggering by the
Flight Data Monitoring software
 Impact on tailstrike margins
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
– Tailstrike margins are reduced (except for the A321 aircraft)
but, for example, roughly corresponds to:
– 5 to 6 degrees on Single Aisle Aircraft family
– 7 to 8 degrees on Long Range Aircraft family
 Tailstrike margins remain comfortable
Landing in CONF 3 - Use of reversers
April 2007
Page 20
Operational consequences
• Use of reversers at Idle:
Potential
increase in runway occupancy time and block time
Additional
brake cooling time: could be limitative in case of
short turn around-time
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
 Must be taken into account for operations
Landing in CONF 3 - Use of reversers
April 2007
Page 21
Content
 General considerations
 Fuel economy estimation
 Additional considerations:
 Other operating cost considerations
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
 Operational consequences
 Pro and Cons: Summary
 Conclusion
Landing in CONF 3 - Use of reversers
April 2007
Page 22
Pro and Cons: Summary
• The economics vary a lot from one airline to another but
pro and cons can be summarized as follows:
Landing in CONF 3
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Use of Idle reverse thrust
Fuel economy
Tires DMC
Brake oxidation
Noise reduction
Brake wear
Brake cooling
time
FOD
Thrust reversers
DMC
Runway
occupancy time
Tailstrike margins
Landing in CONF 3 - Use of reversers
April 2007
Page 23
Content
 General considerations
 Fuel economy estimation
 Additional considerations:
 Other operating cost considerations
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
 Operational consequences
 Pro and Cons: Summary
 Conclusion
Landing in CONF 3 - Use of reversers
April 2007
Page 24
Conclusion
– Airbus recommendation is:
• To maximize safety margins in normal operation, Airbus SOP still
recommends to approach in CONF FULL and to use MAX thrust
reverse for landing.
• For economics, provided runway length and conditions are
favorable, landing in CONF 3 and/or use of idle reverse thrust can
be considered.
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
• No REV landing not recommended
System Safety Assessment based on the fact that reversers are
deployed at each landing
No real benefit in term of fuel economy
Landing in CONF 3 - Use of reversers
April 2007
Page 25
Conclusion
• When applying such procedure, to minimize induced negative
effect, the following could be considered:
• Restrict the application of such procedure on runway where
Autobrake LO can be used and check dispatch conditions.
• Do not override the autobrake to shorten the landing distance
• Pay particular attention on brake fans use
© AIRBUS S.A.S. All rights reserved. Confidential and proprietary document.
Good Dispatcher and Flight Crew awareness is necessary
Clear Airline policy has to be defined for:
- All aircraft types
- All considered runways
Landing in CONF 3 - Use of reversers
April 2007
Page 26

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