Thank you so much for all the responses.
The most useful information was that service is 13 years long (plus 3 years training) - thats a really long time! I initially thought it was only 10 years (and that it would include training). I also found it very helpful to know that a military licence doesn't qualify as a commercial licence as I had thought it would. Weighing up my options I have found this to make the most sense: I could save up more than enough to afford a CPL doing civil engineering work in far less than 16 years... I just hope that I will be willing to give up having an income to go train as a pilot in a few years time, because i'm not sure if doing a CPL part time is managable - by what i've read on other forums it is more difficult than people say.
Could I ask for further response on this new topic: I'm a reasonbly bright student (A aggregate overall for Civil Engineering so far) - would I manage a CPL part time? And how long would this take?
I will also look into the feasibility of working as a helicopter pilot once I have a CPL before I make any final decisions. If anyone has any further information on the jobs avilable in that field please let me know.
I started my PPL in 2009, when I was in Grade 11, and completed it in December 2009. In 2010, I started my CPL while in Matric. I wrote one subject and then decided to focus on school instead, and left the rest of the subjects (7 remained), for 2011. I did hour-building during my Matric year. In 2011 I focused on writing the subjects, building hours, and I had a part-time job. In August 2011 I obtained my CPL with an Instrument Rating. In February this year, I obtained my Instructors Rating. I also turned 20 in January this year.
At school, I was an average, and sometimes below-average student; I excelled in subjects like Biology, but scraped through Maths (HG/Pure), and Science.
I know a number of people that have done similar; a guy that trained at the same school as me did his CPL while in Matric, between being a prefect, and taking part in various sports. Another person I know has just obtained their PPL, despite being a lawyer and working during the week (almost all the training was done on weekends).
Regarding how long it will take to obtain your CPL; it depends on how much work you put in. The PPL has 8 subjects, pass mark of 75%. You need at least 45hrs flying experience before you can do your PPL test. If you fly twice on weekends, you could get 3hrs per weekend (weather dependant). Most people only finish their PPL when they have 55-65hrs.
The CPL is another 8 subjects, pass mark is still 75%. You need a total time of 200hrs before you can do your CPL test. Obtaining the extra hours can be a mission, but you'll do things like your Night Rating (some of the most fun I've had), and maybe even your instrument rating.
At the end of the day, it really depends on you. The lawyer I mentioned above took about 4 months, all part-time.
Like with anything you do in life, if you put the time and effort in, you WILL succeed. I'm not the type of person that likes to study (ironically enough; you never stop studying in aviation), but because I love what I do, I don't mind all the books (most of the time
If you were to train at a place like 43 Air School, it will be more difficult to work full-time and study part-time. But 43 isn't the only school out there (it's also one of the more expensive ones). Obviously the school you decide to go to will depend on where you happen to be living and working.
The nice thing about doing a fixed wing PPL/CPL is that if you decided to get a PPL/CPL on helicopters, the total hours required is slightly less, and you don't need to write all of the subjects (only the ones where there's a difference between fixed wing and helicopter, like aircraft systems).
I think that the best thing you can do right now, is visit some flying schools. Go to as many as you can, and see what they say (chances are they'll all say something different though). Get your hands on some of the PPL material and read through it. Read books like Chickenhawk, just 'cause it's well-written, and hell, why not?
Don't get me wrong, it is a difficult career path. I've spent more time studying than I have in the air (I've got 260 hours flying experience), but there are few things that feel as amazing as lifting off the ground, and seeing the world from a few thousand feet.
Keep the questions coming!