Monday, April 6, 2009


When you look deep at mainstream society, you often find aspects of it that are indicative of their weirdo-on-the-edge roots. Not only that, you sometimes find current practices that seem bizarre. This only goes to show that more people than you think are weirdos at heart, at least in some corner of their psyches. People put on an air of normalcy to avoid attention, peer pressure, etc. but, deep down, many of us harbor secret, non-mainstream wishes and interests. Even in the most normal of activities, there are people who take it "too far" and go off the map. This brings me to the subject of this article: Jets.

Jet airplanes are a normal part of today's society. The military uses them, we fly from place to place in them, there are giant industries that build them, and words and phrases based on the use of jets has found its way into mainstream language - jet lag, for example. Lift the veil and look deeper, though, and you will find the world of jets is a strange, strange place.

Jets work by reaction propulsion. This is the use of expanding gases to create thrust. The first known reaction engine was invented in 150BC by Hero of Alexandria. He called it an Aeolipile. By heating water up in a ball with two opposing bent tubes attached; steam exiting through the tubes creating a reaction force that spun the ball. It was a novelty. No one could think of a use for it.

In the the 18th century Western world, Sir Isaac Newton was the first to theorize that a rearward-channeled explosion could propel a machine forward at a great rate of speed. The first practical uses involved steam. Steam was used to power carriages, mill wheels. and other locomotion devices.

Things got a bit more interesting when various inventors tried to create flying machines propelled by reaction engines. Henri Giffard built an airship which was powered by the first aircraft engine, a three horsepower steam engine. It was very heavy, too heavy to fly. In 1894, American Hiram Maxim tried to power his triple biplane with two coal fired steam engines. It only flew for a few seconds.

American Samuel Langley made model airplanes that were powered by steam engines. In 1896, he was successful in flying an unmanned airplane with a steam-powered engine, called the Aerodrome. It flew about 1 mile before it ran out of steam. He then tried to build a full sized plane, the Aerodrome A, with a gas powered engine. It crashed immediately after being launched from a house boat.

The first patent for using a gas turbine to power an aircraft was filed in 1921 by Frenchman Maxime Guillaume. In the U.S. a few other patent applications followed but Edgar Buckingham of the US National Bureau of Standard published a report saying,"there does not appear to be, at present, any prospect whatever that jet propulsion of the sort here considered will ever be of practical value, even for military purposes."

Dr. Hans von Ohain and Sir Frank Whittle are both recognized as being the co-inventors of the turbojet engine. They didn't know of each other and worked independently on the idea. Whittle could not get institutional funding to work on his idea and had to find private money. Von Ohain was a student and did his work through his university. They both got patents around 1930. Hans von Ohain's jet was the first to fly in 1939. Frank Whittle's jet first flew in in 1941. More info on the history and types of jet engines.

Many major jumps in technological innovation have followed the same pattern: Someone invents a new thing but no one can think of a use for it. Officialdom declares the invention useless or impractical. Inventors privately fund their research and, hopefully, after a period of time, the idea catches on and practical applications are invented.

Once the turbojet engine was invented, enthusiasts pushed the limits. One fun thing to do is to see how fast you can go using a turbojet for power. Officially, the fastest manned, air-breathing jet vehicle is the SR71 Blackbird - about 2,200 mph - a little over three times the speed of sound. In 2004, NASA tested a scramjet (this engine can only operate at speeds faster than sound). It hit nearly 7000 mph or Mach 9.6.

In the world of land speed records, Richard Noble's Thrust SSC set the current world record in 1997 in the Black Rock Desert of Nevada (the same location that the Burning Man Festival is held. The Thrust SSC went 763 mph - faster than sound! It was powered by two afterburning Rolls-Royce turbofan engines developing a thrust of 50,000 lbs. The fuel consumption was about 0.04 mpg. Here's a video.

Some hobbyists spend their free time building jet engines in their garage. One way to do it involves using an automotive turbocharger as the main component. They create engines that make a lot of noise but don't really produce much thrust. Those with more money buy used military and commercial jet engines and mess with them. These hobbyists are itching to attach jet engines to something to see if they can make it go really fast. People have put jet engines in Volkswagens, trucks, go-karts, wheelchairs, bicycles, lawnmowers, beer coolers, and even an outhouse!

At serious government and industrial test locations, scientists and engineers get paid to test jet engines. What fun! Some of the things they do, to make sure the engine can handle whatever it may encounter, is to shoot various things at high speed into the running engine. For example, in testing the GE90-115B Jet engine (the largest jet engine in production) they shot 4.5 tons of water per minute and 3/4 ton of artificial hail into the fan. See a video of this engine being tested.

Birds getting sucked into jet engines is a serious issue. This is what caused a commercial jet to crash land in the Hudson River a month or two ago. Because of this potential danger, engines are subjected to the "chicken ingestion test." Since 1972 they have been using a compressed-air powered chicken cannon (also known as a rooster booster) to shoot chicken carcasses at 180 mph into the engine while it is running at full speed. Not too long ago many testing facilities bowed to pressure from animal rights organizations and switched to fake birds made of clay and plastic. Some urban legends have developed around the chicken cannon. Find out about chicken cannon legends.

In both the history and current use of jet engines we see the activities of people who have gone off the map of mainstream. They go out beyond the edge, find new things, and bring them back as gifts to society. Jets are just one example.