content_image/609433.jpg content_image/609464.jpg content_image/609461.jpg content_image/609462.jpg content_image/609463.jpg content_image/609465.jpg content_image/609449.jpg content_image/609469.jpg content_image/609468.jpg content_image/609467.jpg content_image/609466.jpg
<img src='content_image/609433.jpg'>

## Determining CG, Given Weights, and Arms 

Some weight and balance problems involve weights and arms to determine the moments. Divide the total moment by the total weight to determine the CG. Figure 10-6  contains the specifications for determining the CG using weights and arms. 

Determine the CG by using the data in Figure 10-6 and following these steps: 

1. Determine the total weight and record this number: 

<img src='content_image/609464.jpg'>

2. Determine the moment of each weighing point and record them: 

<img src='content_image/609461.jpg'>

<img src='content_image/609462.jpg'>

<img src='content_image/609463.jpg'>

3. Determine the total moment and divide this by the total weight: 

<img src='content_image/609465.jpg'>

This airplane weighs 2,006 pounds and its CG is 114.8 inches from the datum. 

## Determining CG, Given Weights, and Moment Indexes 

Other weight and balance problems involve weights and moment indexes, such as moment/100 or moment/1,000. To determine the CG, add all the weights and all the moment indexes. Then, divide the total moment index by the total weight and multiply the answer by the reduction factor. Figure 10-7  contains the specifications for determining the 

<img src='content_image/609449.jpg'>

CG using weights and moments indexes. 

Determine the CG by using the data in Figure 10-7 and following these steps: 

1. Determine the total weight and record this number: 

<img src='content_image/609469.jpg'>

2. Determine the total moment index, divide this by the total weight, and multiply it by the reduction factor of 100: 

<img src='content_image/609468.jpg'>

This airplane weighs 2,006 pounds and its CG is 114.8 inches from the datum. 

## Determining CG in Percent Mean Aerodynamic Chord (MAC) 

• The loaded CG is 42.47 inches aft of the datum. 

• MAC is 61.6 inches long. 

• LEMAC is at station 20.1. 

1. Determine the distance between the CG and LEMAC: 

<img src='content_image/609467.jpg'>

2. Then, use this formula: 

<img src='content_image/609466.jpg'>

The CG of this airplane is located at 36.3 percent MAC. 

## Determining Lateral CG of a Helicopter 

For a helicopter, it is often necessary to determine not only the longitudinal CG, but the lateral CG as well. Lateral CG is measured from butt line zero (BL 0). All items and moments to the left of BL 0 are negative, and all those to the right of BL 0 are positive. Figure 10-8  contains the specifications for determining the lateral CG of a typical helicopter. 

