I passed my PPL theory last weekend. Thanks for this forum which has been most helpful and your books which for me hit the target. I quite enjoyed the study and I am considering continuing my studies. I looked at your CPL navigation book and can't see a whole lot of new material in there compared with PPL. No doubt there is, I've only skimmed through the first 50 pages or so. My question is, is there much more study for the CPL exams and then ATPL exams? Can I just walk into the CPL Nav exam with my current knowledge and expect to do as well as I did in the PPL exam? Sorry if this question is too general. Just thought I'd put it out there.
Congratulations Phil on passing the PPL. When it comes to the subject of navigation, the CPL syllabus is very close to the PPL syllabus in terms of topics to be covered. The main difference is in the depth of questions asked. A student who has a sound understanding of PPL nav would certainly get off to a flying start in CPL nav.
The main areas of difference are in the features and limitations of various map projections and the form of the earth. Also, more complex examples of the one-in-sixty rule and calculating the actual wind in fight. Otherwise you are right, there is a lot of common ground in PPL/CPL. Although you may well get a pass in CPL nav relying only on your PPL knowledge, If you want to get a mark that you can be proud of, I recommend that you do the CPL study.