There is no "unfair" charge. You are importing goods into the EU (still, as of 1247z today), so you will be charged tax VAT 20% on (goods value + shipping) at least.
If they accept it being declared as aircraft parts, no customs charge (but I doubt for such parts). If they treat it as car parts, import duty rate of car parts would be additional 4.5% and maybe also a merchandise processing fee.