The centenary of the first manned flight was a unique occasion permitting a rare opportunity to range far into both the past and the future. Most of aeronautics must inevitably be focussed on the near future and immediate actions. However, there are some very long-term underlying issues which are invisible from a day-to-day perspective, but which should not be overlooked as they can be used very often to guide decisions that might otherwise be unsound. In Part 1, the paper reviews the major breakthroughs that have impelled aeronautics along a startling trajectory of success, with some mention of the uncertain beginnings, when even Wilbur Wright considered that all his aerodynamic theories were in a muddle. In that spirit, in Part 2, some attempts are made to anticipate possible breakthroughs that might happen in the 21st century. However, aeronautics does not stand alone. Considerations, such as other transport modes, energy substitution, non-vehicular transport, and the consequences of major global political alignments, will be reviewed in order to seek new aeronautical challenges of the future. Some other long-term, but non-aeronautical engineering, initiatives relevant to the IMechE are introduced and discussed in the appendix