The dream of achieving a vertical flight has always been with Igor Sikorsky, a Russian-born aeronautical engineer for years before managing to develop the first machine that was associated with all we called helicopter today. He actually made several attempts until the dream was achieved. Some of his important failures regarding the building of helicopter is that of Circa that was built in 1910. The dream of eventually being carried into the air vertically came true eight years after submitting a patent for a modern looking helicopter in 1931.
The first practical helicopter was the VS-300 that lifted him up. He never stopped trying to give his best by making improvements on the Vs-300. The past 70 years as actually shown different modification and development towards to the first to the first practical helicopter. Those changes modified the initial helicopters from their unstable and vibrating contraptions which could barely lift its pilot up to present sophisticated machines with various forms of extraordinary functional and flying capabilities. The present machines we have now are able to fly in all directions and perform extra manoeuvres to achieve it functions.
An helicopter can be defined as "any flying machine that uses rotating wings such as rotor with blades to provide lifts, propulsion and controlled forces which will enable the aircraft to hover relative to the ground without forward flight speed to generate those forces"(Gordon Leishman). This flying machine performs several roles as regards to civilian and military functions. The major civilian use include: ambulances, sea and mountain rescue, crop dusting, fire fighting, police surveillance, corporate services and oil rig services while the military uses are troop transportation, mine sweeping, surveillance, assault, attacking and anti-tank mission (Gordon Leishman).
Advancement in aerodynamics has actually helped in the improvement in various aspects of the helicopters for safety and versatility. This can be seen in terms of speed, movement directions, weight, and efficiency. Advancements in technology has now created helicopters with vertical take-off and landing (VTOL) capabilities which has helped in development of different forms of helicopters with ability to combine speed, comfort and flying at higher altitude as seen in the Bell Agusta BA609 (Net Resources International). The design was given by Hirschberg in 1997 and this VTOL designs include tilt-wing and tilt rotor concepts. The problems of the design are that which relates to increased mechanical complexity, increased weight and susceptibility to more aeroelastic problems.
The six fundamental problems that militate against the early development of helicopters as described by Igor Sikorsky in 1938 are as follows: understanding the basic aerodynamics of vertical flight, the lack of a suitable power plant, minimizing structural weight and engine weight, counteracting rotor torque reaction, providing stability and properly controlling the machine and conquering the problem of high vibrations. Most of the basic changes over time as regards to the development of helicopter focused on overcoming these challenges. It was when light weighted engines were produced that the progress towards achieving a vertical flight were achievable.
The first set of helicopters that were produced in relations to military functionality is the S-70(UH-60) Blackhawk. Autogiros were produced and mostly used for observation duties during the World War II (Helis.com). The RAH-66 was produced by Boeing in conjunction with Sikorsky to provide a full scout and attack functionality. OH-58 is one of the most popular of the military helicopters that has been produced and has its advanced version OH-58D with four-bladed rotor with mast mounted sight compared to the original version. Several important innovations have been included in military designs for the development of attack helicopters.
Boeing Vertol Chinook and Kaman SeaSprite are the first versions of AH-566 helicopters that were intend to be a gunship helicopter for military purpose. They were both used in Vietnam War. This gave the military the opportunity to perform airstrike making the war dependent not only on the face-face strike alone (Helis.com). The later versions of those helicopters were then equipped with machine guns, rocket launchers and anti-tank missiles. From military perspective, helicopter is a vital machine or military hardware.
There have been several changes to helicopters especially the military helicopters which seem to be the most commonly designed types of helicopters. The need for airspace attacks and surveillances or transportation of ammunitions has contributed greatly to the need for helicopters. Advancement in aerodynamics and military ammunitions has contributed greatly to different designs.
Work Cited
Gordon, Leishman. A History of Helicopter Flight. 2000. Web. 4 December, 2011.
Helis.com. Sikorsky. Helicopter history site. 2011. Web. 4 December, 2011.
Military Factory. Sikorsky UH-60 Black Hawk Medium Lift Transport Helicopter. 1 October, 2011. Web. 4 December, 2011.
Net Resources International. Bell Agusta BA609. Aerospace-technology. 2011. Web. 4 December, 2011.
