I may be wrong on this, but before the requirements changed and a three year degree was sufficient for chartership requirements.
Aeronautical Engineering degrees simply tended to be those that had full accreditation from the RAEs and IMECE for full exemption from the engineering council exams to gain chartership.
Aerospace Engineering degrees didn't necessarily meet all the academic requirements for chartership; hence graduates would still have to sit Engineering council exams to gain chartership or do some kind of further abridged course. In some cases the degree would only satisfy the requirements for Incorporated membership.