Helicopters

Leonardo da vinci was credited with creating the first design for a helicopter, along with nearly everything else in the world, in the early 1840s, however his design only resulted in toys being produced within his lifetime.

It wasn't until 1906 that the first manned helicopter flight took place, a machine built by Jacques and Louis Breguet, although this machine needed two men to stabilise the craft.

the standard layout for a helicopter is a single main rotor with two or more blades, the fuselage under the main rotor, a tailboom behind the fuselage with horisontal and vertical stabilizing fins, and an anti torque tail rotor.

Controls.

a helicopter has three primary controls

Cyclic (or joystick), between the pilots legs, and held in the right hand (insert dick joke here), the cyclic tilts the rotor disc in the direction the pilot wishes to go, thus pushing the helicopter in that direction. forward to go forward, left to go left etc.

Collective. to the left of the pilot is the collective, which changes the pitch on the blades to change how much lift is produced. these frequently, especially in piston machines, incorporate a twist grip throttle to control rpm.

pedals. these are used to turn the aircraft in a hover and to keep the aircraft straight in forward flight, these usually work by changing the pitch of the tail rotor blades.

Blades.

a blade creates lift by forcing air to go faster over the top of the blade, which decreases it's pressure (don't ask why, it just does), which creates lift. the blades are driven by the engine, however this also creates torque on the fuselage, which would spin the fuselage in the opposite direction to the blades if it weren't for the anti torque tail rotor.

Engines

a modern helicopter will be powered by either a single piston engine, in the case of many smaller machines, or more commonly by one or more gas turbines.

Autorotation.

when a helicopter's engine fails, the pilot will enter an autorotation, which is where the blades are put in flat pitch and are driven by air coming up from underneath the blade (like a sycamore seed)

The Bell Huey

the name "huey" has been given to the h-1 series of bell helicopters first produced in 1956 and still in production today. over the course of it's production, the huey has been extensively refined and improved, and has been made in short and long body variants. the "iconic" huey used in the vietnam war was the long body, single engine, two blade variant, but hueys have been made with twin engines, known as the twin huey, and later with a new four-blade rotor and twin engines, known as the super huey.

contrary to popular belief, the huey "blade thump" is not caused by the blades breaking the sound barrier, but by an aerodynamic reaction that no one really seems to understand. a huey does not always create a blade thump, only at certain speeds and power settings, and many helicopters will produce this sound when placed in a slow descent at high airspeed.

Bell Jet Ranger

the bell JetRanger is a single and twin engine helicopter used by both military and civilian operators, it is available as a short body five seater, or a long body seven seater known as the long ranger. the long body is known as a twin ranger. the first JetRanger first flew on 10 jan 1966 and is set to go out of production in 2010.

Bell 47

The Bell 47 is a two or three seater piston-engined helicopter famous for it's use in vietnam and other conflicts as a medvac helicopter using stretchers attached to it's landing gear to evacuate wounded soldiers. also common as a private helicopter, the bell 47 is becoming increasingly rare as parts are becoming more expensive and harder to find.

Robinson R22

The Robinson R22 is a piston engined, two seater helicopter used extensively for flight training and for private use, although they are also used for jobs such as aerial mustering and for tourist operations. the r22 has been in production since 1979 and is still made today.

Robinson R44

The robinson R44 is a piston engined, four seater helicopter made by robinson. r44s are used in a wide variety of private and commercial operations from tourist flights to agricultural work. first flown on march 1990 and still in production.

Robinson R66

The R66 is a five place, turbine engined helicopter that is expected to go into production in 2010.

Hughes 300/schweiser 269.

a two or three seat helicopter that was used as a trainer by the us military before being replaced by the bell huey. also used extensively for agricultural operations and for tourist flights, as well as by private owners

hughes/MD 500

first flown in febuary 1963, the hughes 500 was initially developed for the united states military, and has been used extensively by both military and civillian operators. The 500 design was bought by McDonell Douglas, and the name was later changed to the MD 500. the 520n and other aircraft developed from the 500 platform feature the NOTAR (no tail rotor) system where air is pumped down the hollow tailboom to a rotating vent to provide anti torque

the MD 600n, a stretched 8-seat version of the 500 featuring the NOTAR boom

Eurocopter AS350/355 squirrel/twin squirrel

first flown on 27 June 1974, the squirrel, and it's twin engined variant, the twin squirrel, have been used in everything from agricultural work to tourist operations, as well as military operations. the EC 130 is a derivative of the squirrel airframe.

EC120

the EC 120 is a five seat helicopter built by eurocopter, with a single engine and a fenestron tail rotor.

EC 130

the EC130 is a seven seat, single engine helicopter built by eurocopter. it is a derivative of the squirrel airframe, with a wider cabin and a Fenestron tail rotor.

bo-105

first flown on 16th February 1967, the bo-105 is used as an air ambulance, as well as being operated by numerous military operators as well as many civilian operators. because of it's rigid rotor head, the bo-105 is fully aerobatic, and an aircraft operated by red bull frequently performs at the red bull air race.

BK117

initially a joint development by messerchmitt-bolkow-blohm and kawasaki heavy industries, and later bought by eurocopter, the bk117 is used extensively as an air ambulance due to it's roomy interior, and in the vip transport business.

AH-1 cobra

using the same engine and drive system of the huey, the cobra saw extensive use in vietnam and other conflicts.

Apache

replacing the cobra, the apache first flew on 1 October 1975. with two engines and a four blade rotor

sikorsky s64 skycrane.

the skycrane first flew on May 9, 1962. used extensively in aerial firefighting and heavy lifting roles, the skycrane can lift ten thousand litres (2650 gallons) of water, or can lift a ten tonne load .

mil-26

first flown on 14 December 1977, the mil 26 is the largest helicopter ever to go into mass production, and the second largest ever produced, the mil 26 can lift 20 metric tonnes, and has lifted 25 tonnes, although the aircraft was immediately returned to the factory to be checked for damage after this lift.