Questions to ask yourself:
1. Do you **REALLY** like mathematics?
2. Do you want to be an engineer?
3. See 1.
If the answer to either of those is no, then I'd consider something else. I did it, and I wish someone had told me this beforehand. It's extremely hard. While your mates on other courses are getting away with 7 or 8 hours a week, you wont be able to meet them at the pub because you'll be in 9-5 a lot of the time, and will have a ridiculous number of degree exams to study for. If you want to fly, pick something nice and easy, and spend your spare time with the UAS.
And just to qualify the above, the academic staff on the course at my uni were second to none, and the course is rightly considered one of the best. But it is only for the dedicated.