Early flight

Early flight

By Wikipedia,
the free encyclopedia,

http://en.wikipedia.org/wiki/Early_flight

This article is a listing of primarily pre-20th century flying machines and work, and an analysis of the debates over early flying machines. The goal is to examine the properties of flying machines, and to list the claims to allow a proper analysis of all the early flying machines. Heavier than air flying machines are included, as lighter than air machines are subject to much less controversy.

Theories

Early attempts at flight are the subject of much debate, both for the often sketchy details of machines and people that have vanished away in time and perhaps as a matter of pride for some given group, like a country. The main focus is the attempts at gliders and powered aircraft in the decades before and soon after the Wright Flyer. Ancient flying machines, gliders, or balloons if they existed are not generally known about or recorded at any level of accepted validity. The first verifiable attempt at controlled flight took place in the 9th century.

In 875, at an age of 65 years, Abbas Ibn Firnas (Armen Firman) built his own hang glider, and launched himself from the Mount of the Bride (Jabal al-'arus) in the Rusafa Area, near Córdoba. The flight was largely successful, and was widely observed by a crowd that he had invited. However, the landing was bad. He injured his back, and left critics saying he hadn't taken proper account of the way birds pull up into a stall, and land on their tails. He'd provided neither a tail, nor means for such a maneuver. He died twelve years later.

"Ibn Firnas was the first man in history to make a scientific attempt at flying."

—Philip Hitti, History of the Arabs

Along with many inventions developed during the Industrial revolution, such as the steam engine, flying machines followed a slow process of study and analysis by various people but culminated in a pivotal design. Following this pivotal design, development continues but with the benefit of some new breakthrough or a slightly new direction. Who receives the award for a specific achievement can be difficult to decide with some developments due to the nature of what was developed, the definition of the award, and veracity of claims. Also, if something was invented independently by different people, conflict can arise as well.

The various benchmarks awarded to flying machines are especially vulnerable to all these.

Veracity of claims

Early flying machines, such those that predated the development of practical photography are often doubted for lack of proof, and ancient machines are almost entirely dismissed for a lack of credibility. Recreations or claims made long after events can add confusion to even the more straightforward cases. The number and quality of witnesses is also often analyzed. Various governments and other organisations will often only give some claims a 'official' approval in attempt to elevate one attempt over another, usually in the interest of a national or cultural pride, or in order to set themselves up as technical and historical authority figures. A great deal of disinformation and revisions can take place as well with some claims, both from individuals and governments, to adjust the level of importance of some respective claims.

Definition of the title

It can be especially rough for more general titles falling prey to technical definitions versus common usage, or differences between languages. More general titles can be favoured for their greater weight, such as a title like 'Father of flight', but could be greatly debated because of being open to interpretation. On the other hand very specific claims can begin to sound trivial, carry less weight, and in being so specific fall prey to debates over accuracy of the claim. What constitutes the most import criteria for a given award is also a matter of debate in early aircraft. Is the 'oldest ancestor of modern aircraft' the earliest design, the earliest prototype, one that actually flew? The arbitrary nature of many titles will automatically create controversy if its not defined specifically. For example, debates over the tallest building tend to break into debates around what constitutes a building and what is the most important measure of such structures height. In the same way some records of flying machines can come down to the exact definition of what constitutes a fixed-wing aircraft.

The nature of what was developed

This is an especially important source of controversy for early flying machines. The source of trouble is the transition between what are considered gliders and what are powered aircraft. Just as objects that displace less water than their weight will sink (see buoyancy), objects that displace less than their weight in air sink also. Balloons and other lighter-than-air craft 'fly' by displacing more than their weight in air to rise, but a flying machine must supply an upward force some other way to remain aloft. Supplying this force requires energy, which brings us to the benchmarks given to the various flying machines. With gliders this energy comes out of potential energy of their height as they trade the energy "stored" by their height for lift and forward speed (aside from taking advantage of air currents).

In powered flight, energy comes from fuel stored aboard (or given to) the machine which is turned into lift in some way. For example, in many aircraft gasoline fuels an internal combustion engine which turns a propeller causing forward motion, which in turn allows the wing to generate lift. Also considered to be important is the ability in early flying machines to control where the device goes, very important for making the device practically useful.

Energy to lift

Anything that falls can trade height for some forward motion, so what becomes very important with powered flying machines is turning stored energy into lift. With a wing, turning forward motion into lift requires turning energy into forward motion or with helicopters directly into lift. The end result requires a moving airfoil to generate an upward force. A good breakpoint for powered flight in design would be if it can not lose altitude or speed in level flight by turning energy into lift. Unfortunately such a device could not take off under its own power(barring numerous complicated exceptions), and such a benchmark would also depends on the conditions of the air, especially the air density. Of course wind conditions can have a big effect as well, with wind from behind extending range and from the front shortening it (for both gliders and powered aircraft).

Also, for example, an engine could be used to build up speed (as could going down a hill) and then forward speed could be traded for lift while maintaining level flight. Other difficulties include a fixed-wing aircraft that derives some lift from attaching itself to lighter than air objects, thus becoming a hybrid. Other matters expand to other facets of claims. Since claims are event based, the veracity of a claim is thought to be capable of being tested by making a recreation of the event. Unfortunately, improvements to a new model can be added or removed, weather condition can vary significantly and even things such as the quality of fuel used can effect a recreation attempt. To make matters worse accurate blueprints are usually difficult to find, and for often the bordline designs small changes can have a big effect. The inability to recreate exactly results in most attempts being of dubious value to the ultimate credibility of a claim, but regardless, a success or a failure can figure heavily in analyzation of a flying machine.

Other issues include a design taking advantage of ground effect which is an aerodynamic effect that adds lift when very close to the ground. If a design is not reported to have risen high enough it is often considered a 'hop', or unsustained leap into the air. Also, starting height, and any additional energy given to aircraft can become a subject of debate. If a motorised design is given energy, and does not demonstrate the ability to climb it may or may not be considered a power flight.

Conclusion

The end result of all this is that it ends up becoming very complicated giving definitions at the borderline of flying machines that are gliders and flying machines that are powered aircraft. Disputes over important titles, such as 'first powered heavier than air flight' can descend into the particulars of design. More general titles like 'father of aviation' add another layer of complexity by implying a societal effect and an effect on other machines.

Many of titles given to various claims vary from country to county, and indeed among various references and encyclopedias - that all use different criteria when considering the validity of a claim, the meaning of the title used, and all the other issues mentioned above. Various advancements are presented here, mostly prototype machines and also some important pieces of literature.

Table of flying machines

Literature, Designs only:

More than design or literature

Note overlapping years in several cases, so all items in this list may not be in strict chronological order.

External links

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Published in July 2009.

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