The term of flying craft is often referred to as 'AERO', which is a four-letter word. AERO is an abbreviation for the term 'AERONAUTICS', which is the science of designing and building aircraft. This includes the study of the principles of flight, the design of aircraft, and the operation of aircraft. AERONAUTICS is a field of engineering that has been around since the early 20th century and has seen tremendous advances in technology over the years. It is an important part of the aviation industry and is responsible for the development of many of the aircraft we see today.