Fastening your seatbelts for a look ahead to the future trajectory of flight over the next century, just consider how much aviation has progressed since the Wright Brothers made their brief inaugural fight just before Christmas 1903. And that's not just the introduction of in-flight entertainment and hot food at 30,000 feet.  Avionics – basically, technology to help pilots fly - has gone from pretty useful but pretty basic things like artificial horizons and altimeters to GPS navigation and auto-pilots. Engines went from sputtering propellers roaring into life with belches of smoke to the first jet – Germany's Heinkel He178 in 1939 – and then onto streamlined wonders able to fly several times the speed of sound.  AIRFRAMESAirframes, meanwhile, have developed from biplanes held together by fragile struts to super-strong metallic structures able to expand and contract with temperature changes or cope with severe G-forces. And the future will hardly see a slackening in the pace of change.  The never-ending drive to reduce weight - improving efficiency, boosting speed and also cutting harmful emissions – is already being boosted by the creation of advanced composite and metallic structures.  Additive manufacture (AM) is one cutting edge technique, where powdered alloy (usually aluminium or titanium) is fused in an inert atmosphere by laser or electron beam. This allows the creation of lightweight parts which allows manufacturers to replicate minimum weight forms seen in nature – like the amazing structure of bird feathers.  Manufacturers are also exploring lightweight composites such as biopolymer membranes produced by living organisms like algae, as well as 'smart' self-cleaning and also futuristic 'self-healing' materials. 3D printing is another technology already revolutionising aircraft manufacture, allowing the manufacture of components impossible to make by old engineering means.  There is also likely to be a move to digital structural safety monitoring via embedded sensors that transmit information in real-time during flights to both pilots and ground staff, as well as any futuristic AI machines tasked with aircraft safety. Though planes will hopefully also still get detailed checks on the ground too!  Increasing the lifting surfaces and aerodynamics of future planes – both supersonic and sub-sonic - will see the appearance of unconventional fuselage and wing shapes, such as sci-fi style 'flying wings' or graceful curved structures. But there may also be 21st century takes on multiple wing structures – like the old biplanes of a century ago – to increase lifting surface.  POWERAirlines are already moving away from petroleum products towards more sustainable fuel sources.  Using biofuels in airliners could cut CO2 emissions by up to 80% compared to today's jet fuel – and since tests began a decade ago, around 2,200 commercial flights have now taken place using biofuels. Research is also proceeding into using things as hydrogen fuel cells – possibly drawing on energy derived using solar power harvested in-flight.  There is also detailed testing of new kinds of engine to make supersonic travel commonplace in the future. The main effort is focused on engines – ramjets – that boost their power using air flow from the plane's passage through the atmosphere. With such engines, future passengers may be able to fly in comfort at several times the speed of sound, slashing journey times.  PASSENGER EXPERIENCEAircraft cabins in the future promise 'smart seats' to ‘fit’ each passenger. As well as moulding to body shape, expect monitoring for things like body temperature, DVT and dehydration. Extras might include at-seat body massage. Designers are also working on cabins designed to allow seats to swivel – to either face towards someone or away from them! Other forms of customisation will include adjusting lighting and ambient music around your seat.  Cabin-crew may also either vanish or be greatly reduced. Passengers may be served by robots gliding up and down the aisle, or helping themselves from self-service food and drink facilities. These could either be like today's self-service machines – or involve 3D food printing more akin to Star Trek replicators!  Virtual Reality (VR) should also become commonplace, allowing passengers to see the amazing view from outside the plane, or immerse themselves in VR recreations of their destination (or fantasy destinations) complete with useful practical information or language tuition. A more out-there VR possibility could be to create virtual travelling companions, whether a friend or some digital manifestation of a celebrity of your choice!  GROUND CONTROLExpect changes with airport transit on the ground too. Increasing use of biometric passports and iris/fingerprint scanning should speed passengers through departure or immigration, while electronic luggage tagging may streamline how baggage is handled.  Edmonton International Airport in Canada is already testing service robots to handle tasks like check-in. And as robot vision and language abilities improve, they will become more capable – perhaps with access to individual customer data to provide personalised service in the terminal.  Despite all the technological advances, the flying experience of today – both on the ground and in the air – can be stressful and uncomfortable. With the number of flights expected to increase sharply in decades to come, anything that makes taking to the air more pleasant can't come soon enough.
Considering the vast improvements in the world of flight since the days of the Wright brothers, the next 100 years will surely see exciting developments in flight.