Man’s fascination with flight can be seen in the 17,000-odd airliners winging through the skies. Modern airliners are 70 per cent more efficient than when they first flew half a century ago. But their CO2 emissions contribute significantly to global warming. So plane-makers are constantly balancing issues of fuel burn, noise and emissions, to design ‘green’, better planes. This is easier said than done. Reducing noise pollution, for instance, increases an aircraft’s weight and drag, which means more fuel consumption — ergo, more CO2. But biofuels can make engines more efficient and less polluting. As can advanced air traffic control systems that allow speedy take-offs, and reduce the in-flight waiting time that force aircraft to circle and waste fuel.
Last week, Boeing signalled a revolution in aviation by unveiling the world’s first ‘green’ passenger jet: the 787 Dreamliner. It uses lighter plastic composites, instead of aluminium, in its fuselage so that it needs less energy to fly. This cuts fuel consumption by 20 per cent, and the plane emits 20 per cent less greenhouse gases. These materials also help it maintain a cabin pressure of around 6,000 feet — 2,000 feet less than in other planes — increasing passenger comfort. Serrated ‘chevrons’ on the engines dramatically lower cabin noise, while advanced gaseous filtration technology increases cabin humidity, preventing symptoms associated with dryness.
So how will the world fly into the future? Just as birds use different feathers on their wings to control flight, aircraft wings of the future could change and adapt to varying flight conditions. They could mimic the way birds land, cutting fuel and runway space required. Airliners are also getting bigger and faster. The mammoth Airbus A 380 carries up to 800 passengers and flies more than 8,000 miles without refuelling. Nasa’s reusable space plane, X-43, flies at more than 10 times the speed of sound on an air-breathing ‘scramjet’ engine, before rocket motors boost it into space.
Space? Yes, look at the Martian atmosphere: despite being thin, it is still ‘flyable’ for solar-powered aircraft like Nasa’s ‘entomopter’ (which flies like an insect by rapidly flapping its wings). Such craft could also fly on Venus and in the upper reaches of Jupiter, Saturn, and Neptune. In fact, low gravity, a dense atmosphere, and low temperatures make Titan, Saturn’s largest moon, the best place in our solar system to fly! Barnstorming, anyone?