According to the Wikipedia, V-22 Osprey can lift 20,000lb of internal cargo, whereas it is able to carry only 15,000lb externally by dual hook. I wonder why there is a difference between external and internal cargo capacity. Is it due to the aerodynamics effect of the cargo?
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5$\begingroup$ May also be due to structural issues, load carrying structures of the hooks may not be able to take more. $\endgroup$– Jpe61Apr 6, 2021 at 10:12
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$\begingroup$ Is a load connected to the hooks a "slung load"? Maybe the pendulum effect of a hanging load makes it harder to control at the max weight. $\endgroup$– zymhanApr 6, 2021 at 13:14
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4$\begingroup$ Hovering is the most inefficient, most power-hungry mode of flight. Is it possible that the 20000 pounds are for a rolling start with horizontal velocity using partially tilted rotors? $\endgroup$– Jörg W MittagApr 6, 2021 at 17:55
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2$\begingroup$ The 20000lb of internal cargo is not going to be a point load, whereas the hook is connected to 1 (or is it 2) point(s) - so it's like having 7.5 or 15,000lb of load in those two spaces [a much strong frame is required for that load than the spread out internal load]. $\endgroup$– Mr RApr 8, 2021 at 22:05
1 Answer
The difference is because when the cargo is inside the aircraft the weight is spread across the cargo compartment floor, whereas when it is carried externally, the weight is concentrated entirely on one or both cargo hooks. The cargo hook attachment points are reinforced, but they still have a weight limit. When the cargo is inside the aircraft the weight limit is the MTOW of the aircraft.