620 ILCS 5/43
Except as hereinafter provided, when such registration is required by the Department, it shall be unlawful for any person to operate or cause or authorize to be operated any civil aircraft within this State unless such aircraft has an appropriate effective license, certificate or permit issued by the United States Government for which a certificate of registration has been issued by the Department which is in full force and effect, and it shall be unlawful for any person to engage in aeronautics as an airman in this State unless he has obtained from the Department a certificate of registration of an appropriate effective airman's license, certificate or permit issued by the United States Government authorizing him to engage in the particular class of aeronautics in which he is engaged, which certificate of registration is in full force and effect.
Aircraft and airmen that are not required to be licensed, certificated, or permitted by the United States government and that have not received a license, certificate, or permit are not required to register with the Department before engaging in aeronautics in Illinois.
620 ILCS 5/43