Embraer EMB145, Operation Manual

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AIRPLANE
OPERATIONS
MANUAL
WEIGHT AND
BALANCE
REVISION 29
1-06-40
Page
7
Code
03
EXAMPLE 1 (EMB-135 MODEL LR):
For the EMB-135 LR on an option 1 configuration (37 seats), with the
passenger cabin divided in three sections.
Section A refers to rows 1 to 4, section B refers to rows 5 to 8 and
section C refers to rows 9 to 13.
Considering the window and aisle seating concept, the first seat to be
occupied is window-row 1, then window-row 2, then windows-row 3,
then windows-row 4, ..., then windows-row 13, then aisle-row 2, then
aisle-row 3, ..., then aisle-row 13.
When window-row 1 is occupied, there is a moment margin of the
passenger weight times the distance between cabin A centroid and row
1 centroid. When window-row 2 is occupied, the moment margin is
increased by the passenger weight times the distance between cabin A
centroid and row 2 centroid. The moment margin keeps increasing
until the seats aft of the cabin centroid start being filled and then
moment margin decreases.
When cabin B starts being filled, the moment margin starts increasing
again and then decreases when the seats aft of cabin B centroid are
filled. The same occurs with cabin C.
The forward seating allowance to be used in the determination of the
constrained CG envelope is the sum of the most negative moment
change of each cabin section.
For the aft seating allowance, a very similar procedure is performed,
but considering the aircraft being loaded from the aft portion of the
cabin.
The following tables show the determination of the forward and aft
seating allowances: