Wis. Stat. § 114.17: Mechanic’s license, issue, presentation.

Any person repairing, adjusting, inspecting or overhauling aircraft or aircraft engines within this state shall be in possession of a mechanic’s license issued to the person by the federal government, which must be presented for inspection upon demand of any passenger, peace officer of this state, or any official, manager or person in charge of any airport or landing field in this state.