A helicopter has two cargo areas. Its forward cargo hold has an arm of 100" aft of the datum and the aft cargo hold has a moment arm of 170" aft of the datum. The total helicopter mass when loaded is 12 400 kg and its centre of gravity 150" aft of the datum. How much mass must be moved from the aft cargo hold to the forward cargo hold to move the centre of gravity position to 145" aft of the datum?
Refer to figure.
The Centre of Gravity must be displaced by: 150’’ - 145’’ = 5’’ (Change of CG), which means that after the new cargo load distribution, the CG moves more forward, because portion of the aft cargo is transferred to the forward cargo area by: 170’’ - 100’’ = 70’’ (Distance moved).
The amount of mass which must transferred to the forward cargo area, can be found applying the "Shifting Load" formula:
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Mass Change / Total Mass = Change of CG / Distance Moved
Solving for Mass Change, we get:
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Mass Change = Change of CG x Total Mass / Distance Moved = 5’’ x 12 400 kg / 70’’ = 886 kg
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Norway1
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Spain1
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