Metal planes are impossible

Lord Kelvin was an exceptional scientist and being wrong about airplanes doesn’t disqualify him from having made contributions to science. However wouldn’t it be interesting if in some way we could show Lord Kelvin our world today? I wonder what Lord Kelvin would make of the Red Bull Air Race, which I attended in London this past weekend (Jul 29, 2007)…

It was an astonishing experience to watch 12 pilots twist through a series of 20 metre high ‘air gates’ – much like skiers would in a slalom. The aircraft used for the race weighed approximately 550 kg on average and carried engines that could generate around 330 HP with top speeds in some cases a little over 400 kph. The characteristics designed into these planes aimed to produce light, nimble, yet powerful flight capabilities – and it seemed as if the designers and engineers had achieved this goal, permitting the pilots to whip through the air gates and execute extreme turns at high speeds.

While it was great fun to watch the air race pilots impress the crowd with their skills, it was also great to know a little about some of the science and technology which allowed them to do so – the pilots were throwing their planes into turns so steep that close to 10G of force was acting on the aircraft and themselves. Most of us know that a ‘G’ is a measure of the gravitational pull on an object. On earth, this force can be measured as 9.8 m/s² - and this is what scientists call 1G. If you were a pilot flying the Red Bull Air Race during tight turns you would experience a force of nearly 10G pulling at your body. This would feel like every part of your body weighs 10 times more than it does now! Imagine trying to lift your arm, or keep your head up with muscles and bones that are accustomed to performing in a 1G environment! Obviously, the air race pilots possessed elite levels of skill and experience and had to train hard to manage the physical demands of the air race.

At times, as the planes threaded through the air gates, I was also struck by the thought that some aspects of what I was observing, remained, from a scientific perspective, very mysterious or poorly understood - principles at work in the flight of these planes such as gravity and inertia. In our day to day lives we react without thought to situations where we are subjected to gravity and inertia - standing on a bus, for example, we grab hold of a pole to keep from falling over when the bus stops suddenly, or accelerates into a new direction. Perhaps, had Lord Kelvin been sitting next to me, on the bus on the way to the air race, or gazing up at the graceful planes along the river, we could have chatted about these issues – but while heavier-than-air-flight has been sorted out the actual forces acting to produce gravitation and inertia, although theorised, remain not conclusively defined or understood.