Generally the big aerospace firms are looking for their engineers to have an honours degree. However, if it's possible, get your ordinary degree under your belt and speak to some advisers at the college/university. You may be able to qualify for a MSc course with the degree, and then take it from there. If you really want to do the honours degree, then don't let the uni people put you off. A friend of mine did an HND before going on to do an honours degree.
Good luck
Mc