Section 6
Weight & Balance
Columbia 400 (LC41-550FG)
RC050002
Initial Issue of Manual: November 10, 2004
6-14
Latest Revision Level/Date: -/11-10-2004
SAMPLE PROBLEM GRAPHICAL METHOD
(Using moments obtained from the Graphs)*
ITEM
WT. (Lbs.)
MOMENTS (1000 lbs.-in. )
Basic Empty Wt.
2,485
260.4 (
Figure 6 - 8
)
Front Seat Wts.
380
42.0* (
Figure 6 - 15
)
Rear Seats Wts.
175
25.0* (
Figure 6 - 17
)
Baggage (Main)
50
8.3* (
Figure 6 - 19
)
Baggage (Shelf)
0
0.0* (
Figure 6 - 19
)
Fuel (At 6 lbs./gal.)
360
42.0* (
Figure 6 - 18
)
Totals
3,450
377.7 x 1000 = 377,700
Figure 6 - 14
WEIGHT AND BALANCE LIMITATIONS
As its name suggests, weight and balance limitations have two components, a weight limitation
and a balance or center of gravity limitation. The maximum gross weight of the airplane is 3600
pounds. This is the first limitation that must be considered in weight and balance preflight
planning. If the gross weight is more than 3600 pounds, then fuel, baggage, and/or passenger
weight must be reduced. Once the gross weight is at or below 3600 pounds, consideration is then
made for distribution of the weight.
The objective in dealing with the balance limitation is to ensure that the center of gravity is
within prescribed ranges at the specified gross weight. The center of gravity range is referred to
as the “envelope.” The center of gravity envelope graph on page 6-18 shows the envelope for the
Columbia 400 (LC41-550FG). Using data from the sample problem in Figure 6 - 14, a CG of
109.5 inches at 3450 lbs. gross weight indicates the airplane, as loaded, is within the envelope.
If the center of gravity is outside the envelope, the airplane is not safe to fly. If the range is
exceeded to the left of the envelope, then the airplane is nose heavy and weight must be
redistributed with more to the aft position. Conversely, if the range is exceeded to the right of the
envelope, then the airplane is tail heavy and weight must be redistributed with more to the
forward position. Notice that the range of the envelope decreases as weight increases. At 3600
lbs. maximum gross weight, the range of the envelope is 108.8 inches to 112 inches, a range of
3.2 inches. At 2600 lb. gross weight, the range increases to 7 inches.
inches
lbs
in
lbs
5
.
109
.
450
,
3
,
.
700
,
377
=
−