Yes, it is. An application form is available. The aeronautical authorisation is charged: € 19,05 to pay on the account of BIPT: IBAN BE68 6791 7078 1634 (BIC : PCHQBEBB), with the reference “Aeronautical authorisation”.
You must enclose:
Please note that you can not use that authorisation on the ground. You must always use the call sign of the aircraft containing the portable radio. Your radio must bear the CE marking and must be accompanied by the EU declaration of conformity. It must also operate on 8.33 kHz.