Activity 1.2.3 Center of Gravity
Center of Gravity
INTRODUCTION
If an object falls toward the Earth without air resistance, about what
point will it tend to rotate? The center of gravity is where the mass of
an object is concentrated or balanced Therefore, an object tends to
rotate about that point Air resistance affects this rotation In this
activity you will calculate the location of the center of gravity for an
aircraft, which affects its stability
The common reference point for
the three axes of the aircraft
Stability
Aircraft stability is the
characteristic of an airplane in
flight that causes it to return to
a condition of equilibrium, or
steady flight, after it is
disturbed
RESOURCES
Activity 1.2.3 Center of Gravity Chart
Resources available online
Forces of Flight and Stability
Resources available online
Procedure
1
Determine whether the aircraft below is loaded within the manufacturer’s
recommendation for safe flight The pilot weighs 165 pounds and there is no co-pilot The
rear seat passengers weigh 251 and 296 pounds There are 98 pounds of baggage and 58
pounds of fuel onboard Complete the table below
Item
Force Weight (lb)
Distance Arm (in.)
Moment (in.-lb) M =
Fd
M
=
weight •
arm
54604 in lbs
Empty Weight
1460
37.4
165 lbs
Pilot
6105 in lbs
37.0
0
Co-pilot
0 lbs
37.0
58 lbs
Fuel
2627 lbs
45.3
547 lbs
Rear seat passenger(s)
39821 lbs
72.8
98lbs
Baggage
9300 lbs
94.9
2328 lbs
112427 lbs
Total
2
If the aircraft is not loaded according to the manufacturer’s recommendation, then
suggest an alternative loading scenario so that the aircraft is safely loaded
Item
Force Weight (lb)
Distance Arm (in.)
Moment (in.-lb) M =
Fd
M
=
weight •
arm
54605 lbs
Empty Weight
1460
37.4
165 lbs
Pilot
6105 lbs
37.0
296lbs
Co-pilot
10952 lbs
37.0
58 lbs
Fuel
Item
2627 lbs
45.3
Force Weight (lb)
Distance Arm (in.)
251lbs
Rear seat passenger(s)
18273 lbs
72.8
98 lbs
Baggage
9300 lbs
94.9
2327
Total
Moment (in.-lb) M =
Fd
M
=
weight •
arm
101862 lbs
CONCLUSION
1. What factors will affect the center of gravity of an aircraft?
Fuel load and baggage will affect the weight as we had to alter them.
2. Explain why calculating the center of gravity of an aircraft is so important
It can affect the aircraft as one side being heavier will cause tipping and could cause
malfunction in some cases.