I’m not native English speaker and there no corresponding word in Chinese so I don’t have idea how to build a logic and best-for word in Esperanto.
I think this would depend a lot on the context of where the word is being used. John Well’s dictionary has the following:
aloft supr-e, -en
However, I think that only makes sense if the word is being used in the general sense of being in a place up high. If I think of something being aloft I generally think of it floating in the sky like a hot-air balloon. In that case ŝvebanta or fluganta might be approriate translations.
ŝvebi (ntr) 1 ♉ Resti kvazaŭ pendanta en la aero, kun etenditaj, ne moviĝantaj flugiloj