NDA, National Defence Academy, is the first aim of every young Armed Forces candidate. Several Armed Forces candidates step toward the NDA exam to join the academy and become a part of any of the three services of the Indian Armed Forces. Advance Defence Academy is the best defence institute in Dehradun which provides you the most interesting facts about NDA. You may also check - How to qualify NDA written exam 1. In NDA, cadets from more than 28 other nations are trained with Indian cadets. 2. NDA is the first Tri-service military academy in the world where three forces Army, Air Force and Navy of defence Services are trained together. 3. There are 18 squadrons in the NDA divided into five battalions. 4. Wing Commander Rakesh Sharma, was the first Indian to fly into space, is an alumnus of the National Defence Academy (NDA), which he joined as an IAF cadet in 1966. 5. Khaki colour was selected for the cadet dress. It was only selected to prevail an atmosphere of homogeneity and unity.