@shon - I did that.. and id urge everyone whose got exams to go study themselves.
I finished both conversion exams aka CPLCG AIR NAV COMPOSITE & REGS in the 2nd attempt. The first attempt was just a trial as i had just landed back frm training like 2 days before the exam so thats like a negligible attempt.
Anyways i studied using GSP's (Ground Studies for Pilots) for NAV / Radio Aids / Flight Planning & MET(4 books), RK Bali's book for AIR REGS and also Reading up DGCA CAR's / AIP / Act of 1937 etc.
Books are available at English Book Store in Delhi. You can buy the GSP for NAV and Air Regs by RK Bali primarily then once done with those go onto Flight Planning and Radio Aids
It took time and lots of looking here n there and a lot of breaking the head on the wall lol. but i did get thru..
To pass the DGCA Exams you also need lotsa luck by your side.. !
But anyways go ahead with this. Im sure a lot of people have done this and aced. If you work hard nthn will be able to stop you from getting done with the exams.
GOOD LUCK
