An Aeronautical Development Agency (ADA) is a government agency that helps create new planes, helicopters, and other types of flying machines. They work with scientists and engineers to develop new technologies that make it possible for people to fly in safer, more efficient, and more affordable ways. They also help create safer ways for people to travel in the air and take part in other activities, like flying for commercial airlines or the military. ADA teams also work on making sure that airplanes and flying machines are up to safety standards and are properly made and maintained.