But the J-10 is highly dependent upon Soviet Material. anyway getting back to the original topic (Chinooks), the US wouldn't sell china them. The US currently views China as a enemy not as a friend, even though they conduct lots of trade together. If the US sells Chinook helicopters it likes basically that the US is funding both China and Taiwan to fight a war against each other. Thats not nice is it. The US can only pick one side, and they've clearly picked Taiwan as their unofficial ally.
Well US sells weapons to both Pakistan and India, eventhough the two countries are fighting each other.