Hi,

Both those fields are pretty different as far as their curriculum and career prospects are concerned. AI engineering is a relatively new field whereas aeronautical engineering  has a solid record and history of being a good branch.

Both of them are niche fields of study, which means that they are suitable for a particular type of job only but I think that AI engineering will take off in the coming years as more and more research is being done in that area. Speaking of research, both fields are solid in terms of research opportunities too.

Aeronautical engineering may have limited job prospects but they are highly paid and require a certain level of skill. AI engineering has not got many direct job opportunities so most AI engineering graduates may end up doing what the IT graduates are doing, if you want jobs and a respectable field then aeronautical is good, if you want to go with the times and contribute in research then AI is great.

Hope this helps.

Good luck.