FLIGHT
OPERATIONS
ENGINEERING
Alternate Forward CG Limits
for Improved Takeoff
Performance
Dave Anderson
PE-201
Operational Performance and
Technical Methods
February 2010
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
1
Alternate Forward CG Limits for Improved
Takeoff Performance
Use of Alternate Forward CG Limits can potentially:
• Increase allowable takeoff weight if limited by:
– Field Length
– Tire Speed
– Climb
– Brake Energy
– Obstacle
• Permit greater use of Reduced Thrust
– Increase Engine Reliability
– Reduce Engine Maintenance Costs
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
2
Alternate Forward CG Limits for Improved
Takeoff Performance
Agenda:
• What are ‘Alternate Forward CG Limits’?
• How CG location affects required lift from wing
• Resultant takeoff and climb performance effects
• Selection of alternate forward CG limits
• Example of benefit magnitudes
• Implementation considerations
• Ordering alternate forward limits
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
3
What are Alternate Forward CG Limits?
• Standard takeoff calculations are based on the
assumption that takeoff CG is at the forward limit
• ‘Alternate Forward CG Limits’ means basing the
takeoff performance calculations on a CG that is more
aft than the forward limit
• The possible improvement in calculated performance
is obtained via a reduction in takeoff speeds
combined with a decrease in drag
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
4
How CG Location Affects Required Lift from Wing
The four basic forces acting on the airplane are:
Thrust, Drag, Weight and Lift
Center of Gravity (C.G.)
Total Airplane Lift
Drag
Thrust
Weight
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
5
How CG Location Affects Required Lift from Wing
The primary components of the Total Airplane Lift are the
lift produced by the wing…
Center of Lift
Liftwing
Weight
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
6
How CG Location Affects Required Lift from Wing
The primary components of the Total Airplane Lift are the
lift produced by the wing…
Center of wing lift is aft of
the airplane CG, producing a
nose-down pitching moment
Liftwing
Weight
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
7
How CG Location Affects Required Lift from Wing
The primary components of the Total Airplane Lift are the
lift produced by the wing…minus the downward force
required by the horizontal tail to offset the nose-down
moment produced by the wing lift
Liftwing
Lifttail
Weight
For Training Purposes Only
(Tail force required
to keep the airplane
in “trim”)
Copyright © 2010 Boeing. All rights reserved
8
How CG Location Affects Required Lift from Wing
For an airplane in stabilized flight the total airplane lift
equals the wing lift plus the (negative) tail down load
Total Lift = Weight = Lift wing + Lift tail
Liftwing
Lifttail
Weight
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
9
How CG Location Affects Required Lift from Wing
Moving the airplane CG forward will require an increase
in the downward force from the horizontal stabilizer to
balance the airplane…
Liftwing
Lifttail
Lift
tail
Weight
Weight
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
10
How CG Location Affects Required Lift from Wing
Moving the airplane CG forward will require an increase
in the downward force from the horizontal stabilizer to
balance the airplane…and a corresponding increase in
wing lift to maintain the same total airplane lift
Liftwing
Liftwing
Lifttail
Weight
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
11
How CG Location Affects Required Lift from Wing
Conversely, moving the airplane CG aft will require a
decrease in the downward force from the horizontal
stabilizer to balance the airplane…
Liftwing
Lift
Lifttail
tail
Weight
Weight
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
12
How CG Location Affects Required Lift from Wing
Conversely, moving the airplane CG aft will require a
decrease in the downward force from the horizontal
stabilizer to balance the airplane…and a corresponding
decrease in wing lift to maintain the same total airplane lift
Liftwing
Lifttail
Weight
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
13
How CG Location Affects Required Lift from Wing
If less lift is required from the wing at aft CG in order to
produce the same total airplane lift:
• At a constant angle of attack the required total airplane lift
can be produced at a slower speed
• At a constant speed, the required total airplane lift can be
produced at a lower wing angle of attack
Liftwing
Lifttail
Weight
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
14
Alternate Forward CG Limits for Improved
Takeoff Performance
If less lift is required from the wing at aft CG in order to
produce the same total airplane lift:
• At a constant angle of attack the required total airplane lift
can be produced at a slower speed
Reduced speed results in a
shorter required field length
8000 ft
Benefit: Takeoff on shorter field length, or with more reduced
thrust, or at an increased gross weight for given field
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
15
Alternate Forward CG Limits for Improved
Takeoff Performance
If less lift is required from the wing at aft CG in order to
produce the same total airplane lift:
• At a constant speed, the required total airplane lift can be
produced at a lower wing angle of attack
Liftwing
Reduced angle of attack results in
less drag, and better climb capability
Lifttail
Weight
Benefit: possible increased takeoff gross
weight when climb or obstacle limited.
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
16
Requirements on Minimum Allowable
Takeoff Speeds
V1
VR
VLOF
V2
35 Feet
Available Runway Length
> V1(MCG)
< VR
< V1MBE
> 1.05 VMCA
> 1.05 VMU (EO)
> 1.10 VMU (AE)
V2 > 1.13 VS1-G
VLOF > 1.05 VMU (EO)
VLOF > 1.10 VMU (AE)
> 1.13 VS1-G
( or, > 1.2 VSFAR)
> 1.10 VMCA
FAR requirements on minimum allowable takeoff speeds
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
17
Takeoff Speed Determination
Boeing determines VR and V2 as functions of takeoff
flap, thrust, and weight:
• Minimum unstick based speed schedule sets
minimum VR required to meet minimum VLOF
• Stall speed based speed schedule - sets
minimum VR required to meet minimum V2
• Other - tail clearance considerations, VMCA
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
18
VMU - Minimum Unstick Speed
• VMU is the minimum speed at which the airplane can fly
at its maximum allowable angle of attack during the
ground roll
• VMU is a function of:
– Takeoff flap
– Thrust
– Weight
• VMU is used in determining the minimum allowable
rotation speed required to meet VLOF requirements
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
19
Minimum Allowable V2 is Based on Stall Speed
• VStall is the minimum speed in the air at which the
airplane can generate enough lift to support the
airplane; defines the maximum CL capability
• FAR 25.107(b) V2 MIN, in terms of calibrated
airspeed, may not be less than -– 1.13VS1-g for 1-G stall certifications
– 1.2 VS for FAR stall certifications
– 1.10 times VMCA established under Sec. 25.149
• VStall is used in determining the minimum allowable
rotation speed required to meet V2 requirements
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
20
Other Takeoff Speed Selection Criteria
Boeing-required aft body ground clearance:
– Examples 757-300, 737NG’s at flaps 1 and 5,
767-400, 777-300 etc.
– In these examples VR and V2 are increased
above the FAR minimum allowable for VMU
and VStall based speed schedules because of
desired tail clearance margin
– Related to VMU requirements because
imposes maximum allowable body attitudes on
takeoff and landing
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
21
Takeoff Speeds Calculation
• For a given weight, altitude, temperature, flap the
takeoff speeds (VR and V2) are calculated based
on considering
– VMU takeoff speed criteria (or Boeing-selected
minimum aft body ground clearance)
AND,
– Stall speed takeoff speed criteria
• Higher of the two criteria is the most limiting and
becomes the speed which is published and used in
takeoff calculations
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
22
Takeoff Speed Determination
• Long aft body airplanes are typically limited by
VMU takeoff speed criteria
• Shorter aft body airplanes are typically limited by
stall takeoff speed criteria
• Most airplanes have some flaps VMU limited and
some stall speed limited
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
23
Lift as a Function of Angle of Attack – the Lift Curve
• Lift coefficient increases as angle of attack increases until an
angle of attack is reached where the airflow over the wing can
no longer stay attached and begins to separate
• At greater angles of attack this separation increases until
eventually the wing reaches its stall angle of attack
increased
separation
CL max
Airflow in a
stalled condition:
Lift
Coefficient
CL
flow
separation
begins
angle of
maximum
lift
angle of
zero lift
(-)
0
(+)
Airplane Angle of attack (α)
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
24
Lift as a Function of Angle of Attack – the Lift Curve
Lift Coefficient
+
-
CL Max Lift @ αMax Lift
0
Angle of Attack (AOA)
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
+
25
Speed as a Function of Lift Coefficient
Basic Lift Equation
1
2
L = ρV CLSREF
2
L= lift
ρ= rho (air density)
V= air velocity (TAS)
CL= coefficient of lift
SREF= wing area
In level flight the speed required to produce a
given amount of lift is:
V =
Weight
1
ρCL SREF
2
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
26
Speed as a Function of Lift Coefficient
In level flight, stall speed (Vs) is then:
VS =
Weight
1
ρCL S SREF
2
CLMAX
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
27
Lift as a Function of Angle of Attack – the Lift Curve
• A further aft CG shifts the lift curve upward at all
angles of attack
• The field length benefit comes from a reduction in
speed required to produce a given amount of lift at
a given angle of attack
CL max
Body attitude-limited
angle of attack (VMU)
Airplane Lift
Coefficient
CL
(-)
0
Stall angle of attack
Aft CG
Aft CG
Fwd CG limit
angle of
maximum
Lift
(+)
Airplane Angle of attack (α)
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
28
Alternate Forward CG Limits for Improved
Takeoff Performance
180
170
CG assumed for
standard takeoff
160
calculations
Aft Flight and Landing Limit
150
Fwd Takeoff and Landing Limit
130
120
110
100
90
80
0
Fwd Flight Limit
Gross Weight – 1000 LB
140
5
10
15
20
25
30
35
40
Center Of Gravity - % MAC
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
29
Alternate Forward CG Limits for Improved
Takeoff Performance
180
CG’s assumed for
alternate fwd CG
calculations
170
120
110
100
90
80
0
5
10
15
20
25
Aft Flight and Landing Limit
Fwd Takeoff and Landing Limit
130
Fwd Flight Limit
Gross Weight – 1000 LB
140
Alternate Fwd Takeoff Limit 2
150
Alternate Fwd Takeoff Limit 1
CG assumed for
standard takeoff
160
calculations
30
35
40
Center Of Gravity - % MAC
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
30
Speed as a Function of Lift Coefficient
With alternate forward CG based speeds:
V =
Weight
1
ρCL SREF
2
• The CL associated with any given angle of attack (e.g.,
stall angle of attack, or body-attitude limited angle of
attack) increases as CG moves further aft
• This CL increase results in lower required speeds to
produce a given amount of lift at a given angle of
attack (e.g., lower stall speed for a given weight)
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
31
Takeoff Speeds and Takeoff Distance
Reductions in VStall and VMU allow reductions in V2
and VLOF, and therefore the VR required
V2 ≥ 1.13VS1-G
VLOF ≥ 1.05VMU(EO)
V2 ≥ 1.2VSFAR
VLOF ≥ 1.10VMU(AE)
Reductions in VR, VLOF, and V2 will shorten takeoff
field length required for a given weight, or increase
allowable weight from a given takeoff field length
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
32
Lift as a Function of Angle of Attack – the Lift Curve
Another benefit of moving CG further aft is a reduction
in the angle of attack required to produce a given
amount of lift at a given speed (i.e., a constant CL)
Alt fwd CG
Airplane Lift
Coefficient
CL
Fwd CG limit
1
2
L = ρV CLSREF
2
(-)
0
(+)
Airplane Angle of attack (α)
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
33
Drag as a Function of Angle of Attack
(-)
it
CG
Drag
Coefficient
CD
Fw
d
Airplane Lift
Coefficient
CL
lim
Al
tF
w
d
CG
This reduction in angle of attack results in a
reduction in drag at a constant CL
0
Drag reduced
(-)
(+)
Angle of attack (α)
0
(+)
Angle of attack (α)
Benefit : Reduced Drag
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
34
Alternate Fwd CG Affects Takeoff Climb Gradient
Climb gradient (γ) is the ratio of the increase in
altitude to the increase in horizontal distance and is
normally expressed in terms of percent:
Δalt T − D
γ=
∝
Δdist
W
L
L
T
Δ altitude
γ
Δ distance
D
W
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
35
Alternate Fwd CG Affects Takeoff Climb Gradient
• Further aft CG decreases drag at a constant CL
relative to a forward CG
• For a fixed speed this reduction in drag will improve
the climb gradient
Δalt T − D
γ=
∝
Δdist
W
Benefit : Improved Climb Gradient
(usually, but not always!…)
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
36
Climb Gradient Versus Speed
2.4%
Weight 1
p
Im
Increasing
Weight 2
V2
V2
b
im
Cl
d
St
Gradient
Remember that Increasing Climb Speed (i.e., use of
improved climb speeds) may:
– Improve climb gradient capability for given weight
or,
– Allow a higher weight for fixed gradient
Speed
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
37
Climb Gradient Versus Speed
• Slower, alternate forward CG speeds are like ‘negative’
improved climb
• Climb gradient could actually decrease with alternate
fwd CG V2, depending on the magnitude of the aft CG
drag improvement
2.4%
Weight 1
Increasing
G
2
dV dC
St
w
tF
Al
Gradient
Improved gradient due to
alternate forward CG
drag improvement
Weight 2
V2
Speed
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
38
757-200/RB211-535E4
(Example Only)
Stall speeds for all flap
settings are decreased
with more aft CG
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
39
757-200/RB211-535E4
(Example Only)
Takeoff speeds for all
flap settings are
decreased with more
aft CG
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
40
757-200/RB211-535E4
(Example Only)
Field length-limited
weight is increased
with more aft CG at
both Flaps 20…
For Training Purposes Only
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41
757-200/RB211-535E4
(Example Only)
…and Flaps 5
For Training Purposes Only
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42
757-200/RB211-535E4
(Example Only)
Climb-limited weight is
increased with more aft
CG at Flaps 20…
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
43
757-200/RB211-535E4
(Example Only)
…but decreased by a
small amount for
further aft CG’s at
Flaps 5
Climb-Limit
Weight
Decrease
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
44
Climb Gradient Versus Speed
Recommendation:
Investigate climb gradient differences for your
particular airframe/engine combination before
assuming any amount of climb gradient benefit
does, or does not, exist
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
45
General Benefits Summary
Moving the CG aft from the forward limit will:
• Permit scheduling of lower takeoff speeds, resulting
in shorter field lengths,
• Decrease drag at a given speed and weight,
improving climb performance at that speed
Benefits: Shorter Field Length, Increased Climb
Capability, possible increase in allowable
Takeoff Weights
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
46
Selection of Alternate Forward CG Limits
• Per FAA AC 25-7A, Chapter 8, Paragraph 240 c. and
c.(1)(i) only two alternate forward CG limits may be
granted per operator for a particular airplane type and
model
• It may be possible to select one of those two alternate
forward CG limit based on a value that can easily be
achieved with no changes to an airline’s current
loading procedures...
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
47
Selection of Alternate Forward CG Limits
Proposed Limits
• Determine an easily
attainable alternate FWD
CG by evaluation of
dispatch loading records
180
170
150
130
120
110
100
90
80
0
Fwd Takeoff and Landing Limit
Gross Weight – 1000 LB
140
5
10
15
20
Aft Flight and Landing Limit
Alternate Fwd Takeoff Limit 1
160
25
30
35
• Airline may propose this
first alternate forward CG
choice to their
regulatory authority and
normally meet it based on
no changes to existing
loading procedures
40
Center Of Gravity - % MAC
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
48
Selection of Alternate Forward CG Limits
An airline might also select an additional, further aft,
alternate limit that would require loading procedures
that are different from their ‘standard’ procedures
in order to further optimize operations for a particularly
challenging airport or route
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
49
Selection of Alternate Forward CG Limits
Proposed Limits
• Airlines may propose two
alternate forward c.g.
locations to their regulatory
authority; the second (further
aft) limit may require ‘special’
loading procedures
180
170
120
110
100
90
80
0
5
10
15
20
25
Aft Flight and Landing Limit
130
Fwd Takeoff and Landing Limit
Gross Weight – 1000 LB
140
Alternate Fwd Takeoff Limit 2
150
Alternate Fwd Takeoff Limit 1
160
30
35
• Consider what takeoff CGs
you could reasonably load to
with possibly some changes
to your standard/normal
loading procedures
40
Center Of Gravity - % MAC
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
50
Example of possible benefit obtained
by using alternate forward CG limits
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
51
Example Benefit of Alternate Forward CG
Field Length Limited
Field Length = 5,000 FT (Renton, WA)
Example 737-800
Engines = CFM56-7B26
Basic Fwd CG Limit = 6% MAC
Runway = Dry
Wind = No Wind
Altitude = Sea Level
OAT = 15C
Slope = Zero
Takeoff Flaps = 25
Landing Flaps = 40
No Improved Climb
Balanced V1
MTOW = 78,244 KG
MLW = 65,317 KG
Note: used AFM-DPI for calculation analysis.
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
52
Example Benefit of Alternate Forward CG
Takeoff Weight Benefit* ~ kg
Fwd Limit 6%MAC
Alternate Limit 15%MAC
Δ Weight
Field Length Limited
63657
64309
652
Climb Limit
76081
76100
19
Brake Energy
not limiting
not limiting
n/a
Tire Speed
not limiting
not limiting
n/a
Weight Improvement = 652 KG (about 7 Passengers, based upon 90 KG/Pass with carry-on baggage)
* Analysis assumes NO obstacles
Landing weight increases can often also be obtained (due to same effects
that produce takeoff weight increases)
Landing Weight Benefit ~ kg
Field Length Limited
Approach Climb
Landing Climb
Brake Energy
Tire Speed
Fwd Limit 6%MAC
60981
81643
81992
not limiting
not limiting
Alternate Limit 15%MAC
61845
Δ Weight
81689
82053
not limiting
46
61
n/a
not limiting
n/a
864
Weight Improvement = 864 KG (about 10 Passengers, based upon 90 KG/Pass with carry-on baggage)
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
53
Additional Benefit of Alternate Forward CG
Greater allowable thrust reduction
Using Alternate Forward CG Limit performance
allows greater opportunities for reduced thrust
operations, increasing engine reliability and
reducing engine maintenance costs.
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
54
Examples of Alternate Forward CG Benefits
Model
Engines
Alt. CG
737-800
CFM56CFM56-7B27
15%
757-300
RB211RB211-535E4
14%
777-200ER
GE90GE90-94B
23%
767-300ER
CF6CF6-80C2B7F
19%
747-400
CF6CF6-80C2B5F
20%
Δ Wt(KG)/
Δ OAT
Δ Reduce
Pax**
Pax**
/Flex Temp
Thrust
+20C
-1.5%
+20C
-2.0%
+20C
-1.5%
+30C
-2.0%
+30C
-3.0%
500 KG/
6 Pax
900 KG/
10 Pax
1600 KG/
18 Pax
2100 KG/
23 Pax
4800 KG/
53 Pax
**Example Δ weight only; actual Δ weight will depend on specific conditions
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
55
Implementation Considerations
• No modifications are required of either inservice or future airplanes to take advantage of
this takeoff performance improvement
• Requires purchase of AFM appendix or
AFM-DPI Authorized Alternate Performance
Capability
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
56
Implementation Considerations
To implement Alternate Forward CG Limits it is important to:
• Maintain good Weight and Balance records
• Revise AFM and Weight and Balance Manual
• Revise Loading System
• Provide necessary training for flight, ground, and dispatch
crew to ensure accurate loading and calculations
• Implement Dispatch, Flight Planning, and Loading
procedures
• Understand how to obtain Alternate CG data from:
– AFM or AFM-DPI
– Operational Software: BPS/STAS/BTM/BTOPS
– Onboard Performance Software: BLT/OPT
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
57
Implementation Considerations
When selecting Alternate Forward CG Limit values, it is
important to:
• Consider interior configuration, number of
passenger classes, location of galleys, cargo
loading policies
• Review Load Planning records to establish existing
loading patterns
• Evaluate whether a more aft CG can be obtained
by changing existing loading procedures
• Account appropriately for effect of curtailment
as with any forward takeoff CG limit!
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
58
Implementation Considerations
When using Alternate Forward CG Limits:
• Data provided by ground operations and dispatch
takes precedence over that shown by any
onboard system (e.g. FMC takeoff speeds) other than
an on-board calculation tool such as OPT that can
account for alternate FWD CG effects
Operational Data:
• Dispatchers and Flight Crew must have Runway
Analysis data available for each of the optional forward
cg limit values they may select for the takeoff, either via
paper, transmitted from ground calculations, OPT, or
some other on-board calculation tool
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
59
Ordering of Alternate Forward CG Limits
Contact Boeing “Technical Services and
Modifications” with your request:
• Phone: 206-655-2602
• FAX: 206-766-5213
• E-mail: [email protected]
Order on-line via “Flight Technical Services”
catalog on myboeingfleet.com
For Training Purposes Only
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60
Ordering via FTS Catalog on mbf.com
From the mbf home
page select FTS catalog
For Training Purposes Only
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61
Ordering via FTS Catalog on mbf.com
Select ‘New Order’
My Airline’
Airline’s Name
For Training Purposes Only
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62
Ordering via FTS Catalog on mbf.com
My Airline’
Airline’s Name
Select Alternate Fwd
Center of Gravity
For Training Purposes Only
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63
Ordering via FTS Catalog on mbf.com
My Airline’
Airline’s Name
Select ‘continue’
Select Model
Select Desired
Serial Numbers
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
64
Ordering via FTS Catalog on mbf.com
My Airline’
Airline’s Name
Select ‘continue’
Input desired
alternate
forward CG’s
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
65
Ordering via FTS Catalog on mbf.com
My Airline’
Airline’s Name
Select ‘continue’ and follow
instructions for submitting
final ordering information
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
66
Summary
Alternate Forward CG Limits can potentially:
•
Increase allowable takeoff weight if limited by:
– Field Length
– Climb
– Obstacle
•
Permit greater use of Reduced Thrust
– Increase Engine Reliability
– Reduce Engine Maintenance Costs
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
67
FLIGHT
OPERATIONS
ENGINEERING
End of
Alternate Forward CG Limits
for Improved Takeoff
Performance
PE-201
Operational Performance and
Technical Methods
February 2010
For Training Purposes Only
Copyright © 2010 Boeing. All rights reserved
68