Akuparian Autogyro

Autogyros are heavier than air aircraft which use an unpowered, autorotating rotor to hold them aloft. They are the main type of aircraft operated on Akupara Island and are built in all varieties by their enthusiastic inventors.

Appearance
Autogyros on Akupara have two typical appearances. Some autogyros are incredibly ornate machines that have been lovingly crafted by their builders and feature carvings in their woodwork or have a fuselage designed to resemble dragons, birds, fish and the like. The other type you see are built with absolutely no asthetic in mind at all. These craft are typically build by newcomers to the hobby. Regardless of this, most autogyros resemble simple fixed wing aircraft with a rotormast placed atop the fuselage.

Either of these two types can come in one of several configurations. These configurations concern the position and type of propulsion employed. The ones using flapping wings almost always have the flapping wings placed in line with the rotormast. Propeller driven machines vary more. The most common place to have the propeller positioned is on the nose since these are the most stable and are much easier to design and build. Having the propeller prositioned at the rear of the aircraft is also done since it offers better visibility and speed but these are only ever really built by the best engineering talent on the island since they require much more knowledge and experience. Multi-engined autogyros are very rare but do exist. Some of these have the propulsion units positioned in tandem in an effort to reap the advantages of both normal configurations whilst some of these have the engines positioned side by side on wings in an effort to produce more lift.

Undercarriage is also a variable. All undercarriage is fixed since it is lighter and easier to build. Most autogyros are wheeled with small skids to prevent them from tipping over. The skid is considered a vital addition since most of them operate from unprepared airfields. Obviously on an unprepared airfield the floor is not going to be smooth. The skid makes the difference between a bumpy landing and an embaressing landing where the engineer is stuck with the tedious job of rebuilding rotorblades.

Floats are also used by most of the people who operate autogyros by the coast or over water. Because engine failures are still moderately common, using floats over water has become common practice. Autogyros are infamously difficult to escape from when submerged and crashes in water have claimed the lives of many Akuparians. Float configurations also vary depending on the builder's preference with some even incoporating wheels into their floats to offer their machine amphibious capabilities.

How They Work
As mentioned above autogyros work with an unpowered rotor which is kept in permanent rotation as long as the craft is in the air. This is because the blades have a specific profile and pitch which means that as air passes over their suface they produce lift and a force which causes the blades to move forwards. The blades are hinged at the hub to allow them to flap up and down as well as allowing them to hinge forward and backwards from the hinge. This is neccesary since rotor blades never produce the same amount of lift regardless of how well they are built since different blades on the same rotor are subject to different airflows and speeds. In flight, as blades rotate towards the nose of the craft they are subject to much more wind, and thus lift, because of the air that the craft is moving into as it flies forwards whilst the blades moving with the wind towards the tail are subject to less wind and lift. This creates an inbalance of lift which would flip over an autogyro without hinged blades. The hinges simply allow the rotors to find their own path through the air without rendering the whole craft uncontrollable. Centrifugal forces prevent the blades from folding up like an overturned umbrella but whilst the craft is on the ground and the blades are not turning, wires from the rotorhub prevent the blades from drooping down and striking the ground or the craft.

The hinges that allow the blades to move forwards and backwards from their hub are simply an addition which reduces the strain on the flapping hinges. Whilst autogyros can fly without these extra hinges, rotorhubs without these hinges are found to have a much shorter life expectancy since they are subject to much more strain and wear.

Since the rotors are unpowered, a propulsion unit of some description is neccesary to allow the ship to maintain flight. On Akupara this usually comes in the form of either a clockwork driven propeller or flapping wings. Autogyros without a source of propulsion are known as gyrogliders which are either freely glided until they gently descend back to the ground or they are towed by surface vehicles.

History of Operation
Prior to the invention of Autogyros on Akupara, multi-winged fixed wing aircraft were used. These planes were the first heavier than air aircraft to fly. They were flimsy and lightly built, often with as many as four or five sets of wings to make up for the lack of power from their engines. These aircraft, although suitable at the time were never destined to get far. Although engine power gradually increased and the number of rediculous looking wings dropped, they could never develop fast monoplanes because of the requirements for large runways which would have to be built on large plots of land where giant monsters lived. Attempts were made and human lives were lost. It quickly became apparent that these runways could never be built.

People then attempted to dabble with helicopters and vertical take off flight but these were either underpowered, uncontrollable or simply made too much noise. Further lives were lost in attempts to further developments in powered flight.

Finally a series of windmill owners in a lone village to the north of the island came up with an idea. They studied their own windmills and the aerofoils used by the simple planes of the time and eventually came up with an aerofoil that produced lift, like usual, but had properties borrowed from the windmill that allowed it to rotate in the wind thus producing lift without the noise associated with powered rotorflight. The idea was to attach this rotor to a plane fuselage that would pull the rotor into the wind, making the craft fly.

Models were tried and tested and showed promising results but when they finally managed to acquire a full size plane to test their invention on it ended in failure. After several rebuilds and several more failures they went back to the models and re-examined them. They found that the models bamboo blades were flexible. It was decided that this was probably the key to its success. The engineers knew that flexibility was something they probably could not emulate on the fullsize machine so they employed hinges instead. This resulted in success and the autogyro was created.

The new machine offered the speed of new planes with a much shorter take of run, smaller even than the old planes. This was reduced further when mechanical, clutch operating rotor starts were employed. Fixed wing steering was gradually replaced with rotor operated steering which made the aircraft handle better at low speeds. Finally jump start takeoffs were discovered allowing them to nearly take off vertically. The autogyro, combined with its ease of operation and versatility quickly replaced most of the fixed wing aircraft on the island. Only a few planes are still operated.

Autogyros on Akupara Island
Autogyros are the most common form of aircraft found on Akupara Island. They are used for agricultural purposes, recreation, personal transport and fishing as well as some minor self defence force purposes. Within agriculture they are used mainly for crop spraying although some of the more radical pilots fly them for herding animals. Within fishing some of the more mechanically minded fishermen have an autogyro kept on deck as a spotting aircraft which can direct the traulers towards shoals of fish. Gyrogliders are also used for this since they can be towed behind boats.

Since the clockwork engines on Akupara can only lift so much, most autogyros are only big enough to carry two or three people at any one time. One or two exceptions to this rule may exist but these are anomolies. That is why these craft are only used for personal transport whilst large scale transport is achieved through airships.

Within the Akuparian self defence force autogyros are employed to distract and draw giant monsters away from populated areas. Armed with small incendiary bombs and rapid fire guns they get the monster's attention by firing the guns at them and then use their speed and agility to lure the monsters away from towns and villages. Once very far from civilisation they release the bombs to give the monster a new noise to focus on. Once the monsters have eliminated the source of noise made by the bombs they have, usually, forgotten about the town or village they were attacking and go back to harmlessly roaming the country side. Occasionally more radical measures have to be taken but this tactic does have a high success rate.

Other roles for autogyros do exist but these are far too numerous to be mentioned.