JOURNAL OF CRITICAL REVIEWS ISSN- 2394-5125 VOL 7, ISSUE 19, 2020 VTOL: HOW DO THE TECHNOLOGIES OF AIRCRAFT VERTICAL TAKE-OFF AND LANDING WORK?-A NEXT GENERATION OF FLYING Sunilkumar Gopakumar1, Rathan N2 1sr.Engineering Manager, Collins Aerospace 2assistant Professor, Hindusthan Institute Of Technology Received: 14 April 2020 Revised and Accepted: 8 August 2020 ABSTRACT: In the case of extreme departure and landing conditions, the need to move troops to and out from the battle front demanded the ability of the transport aircraft to take off and to land vertically. VTOL Aircraft were eventually taken out of the design and characteristics of current turbojet engines which were capable of vectoring the V22 Ospreys, and the F35 Lightning-II. The avionics industry giants Pratt and Whitney, Boeing, Rolls Royce had their own roles in the late 1950s, both with turbo shafts and turbo fans. Since then, VTOL engines have all been designed to meet their demands. KEYWORDS: Vertical Take-off and Landing, Short take-off and Landing, Aircraft I. INTRODUCTION As we all know we are entering into the next phase of air travel which is called VTOL. VTOL is nothing but vertical takeoff and landing. In layman's terms this can take off from anywhere and land anywhere vertically, next version of a helicopter. Research is going to make this fully automotive where you just enter the source and destination and reach where you want to. Companies like Uber, Lilium, Airbus are in their prototype phase expecting their first sale to be started somewhere around 2025. In this article I will talk about what is VTOL, types of VTOL, its operation, advantages What is VTOL? VTOL is where an aircraft can take off, hover and land vertically. History of VTOL The story of the VTOL was first used in Leonardo da Vinci's sketchbook by Margaret Rose, thousands of years ago. He drew up a picture of what the helicopter would be. The first helicopter prototype flew in 1907 and was not modified before World War II. Other VTOL solutions were evaluated between 1920 and 1930 in addition to the helicopter. Henry Berliner experimented with a fixed-wing horizontal rotor airplane between 1922 and 1925. The patents for somewhat impractical VTOL fixed aircraft with tilting engines were awarded to Nikola Tesla and George Lehberger from 1928 and 1930. The patent was awarded to Leslie Everett Baynesses for another rotor aircraft, the Baynes Heliplane, at the end of the 1930s. More than forty V / STOL aircraft were evaluated from the 1940s to now, but only four did actually produce it. The British Harrier jumper and his descendents, the Soviet transportation aircraft An-72/64, the Soviet Naval fighter Yak-38, and the Bell / Boeing V-22 Osprey were all four achievements in the process. The V-22 Osprey is the first tilt rotor aircraft to be built in the world [8]. In the 1960's attempts were made to develop VTOL commercial passenger aircraft but none succeeded in producing them. Both designs have been rejected as too expensive and heavy to operate.The V / STOL Tilt- Wing monoplane, which is an aircraft with only 1 wing — was built by Canadair from 1964 to 1972, was known as CL-84. The Canadian government has ordered a military review of three modified models. The names of these aircraft were CL-84-1. The U.S. displayed and tested the CL-84-1 between 1972 and 1974, at USS Guam and USS Guadalcanal aircraft carriers as well as elsewhere. Unfortunately, two of the CL-84s suffered mechanical problems and were never awarded crashes during testing and development contracts.Germany planned to manufacture three VTOL aircraft in the 1960s and early 1970s. There were two versions but, due to high costs and political issues, the concept was cancelled. The VTOL aircraft began designing and developing with the application of turbo shaft motors for a trustworthy form of the rotor craft on a helicopter. They were only used to transport troops quickly and easily to the battlefield from the base site or from the aircraft carrier. In the past, the helicopters have been restricted to 7290 JOURNAL OF CRITICAL REVIEWS ISSN- 2394-5125 VOL 7, ISSUE 19, 2020 altitude, range and transport. Such limitations led to the production of supersonic turbofan motor VTOL devices that provide comprehensive air support capabilities. Bell helicopters and Boeing Rotorcraft systems examine in depth the design features and difficulties involved in the development of the V22 Osprey. In the following parts you can learn about the invention of fans with turbo for the Harrier Jump jet as well as Lockheed Martin F35 Lightning-II. VTOL Criteria As consequences from Second World War it was clear that aviation technology was an important factor in the assessment of the result. In inspiring the Allies to dominate the aerospace, the end of the Second World War played an important role in gaining tactical advantage in the fighting. There was a great advantage in deploying troops rapidly on war fronts and retreating with minimal casualties. This resulted in the use as transport vehicles of helicopters, which are the oldest form of VTOL aircraft. The helicopter’s large yet efficient rotor blades restrict its speed, altitude as well as range. It was necessary to build a high speed and efficient glider. In 1985, V22 Osprey was built in collaboration with Bell Aircraft Corporation and Boeing Rotorcraft systems. The Harrier Jump Jet, developed in the 1950s, is the most successful vertical takeoff and landing aircraft in the history of aviation. Category The technology VTOL is categorized primarily according to the complexity of demands such as transport and air strikes. The VTOL-technology class of carriages is primarily rotors like Helicopters, Gyrodys, tilt rotors and tilting wings that use state-of-the-art motors with turboshaft. Cyclogyo and heliogyro designs are recent developments that since their first prototypes have been futuristic and unfathomable. The attack jets that use VTOL technology, on the other hand, mainly have a low weight and powerful turbofans, and are assisted by power-lift enthusiasts for the starting-off. Design thoughts and concerns Driven by a VTOL aircraft's type of engine and its application, the design principles and main restrictions of engines are classified. The developments in this technology are thus recorded in chronological terms. Different rotorcraft designs gathered in popularity in the 1960s, as the aerospace industry grew. Many rotorcraft designs, including Helicopters, Autogyros, Gyrodynes, Cyclogyros and Heliogyros, were done in the past. Helicopter It is better to understand a helicopter's design features thoroughly. The principal criteria are horizontal stability, vertical stability, precessory stalled stability, tail rotor stability and rotor flutter. The first and foremost requirement is a high thrust to weight ratio which helps to increase the lift strength required for vertical starts. The need for landing equipment eliminates this. The high angular speed of the rotor blades makes much flat and unflat pitch, seal and roll stability. Therefore, the design of the turbo shaft engine that drives the motor is directly limited. There is a standard rotor at 450 rpm on a helicopter. In order to stabilize the aircraft in flight, a torque counteraction mechanism is most important. The stabilizers are placed horizontally and vertically on the mast to preserve stability in pitch and water. Helicopter flying is a specialty. It sets a cap on the spectrum. A significant feature of the architecture is also a lightweight structure. Vibration and noise are the most common obstacles to build a helicopter. Through various evolution and methods noise are minimized. A primary consideration to assess engine parameters is the vertical drag on a helicopter. With turbo shoe engines with a clean nacelle configuration, most rotorcraft manufacturers build a high-speed gearbox to prevent precessional drag-and - drop. Figure 1 shows the structure of a helicopter 7291 JOURNAL OF CRITICAL REVIEWS ISSN- 2394-5125 VOL 7, ISSUE 19, 2020 Figure 1: Helicopter Gyrodyne Composite helicopters use the same technology as vertical departure and landing helicopters and fuse pumped with wings as seen in Figure 2. Propulsion drive design factor is unique since the motor's shaft power drives the main rotor and two auxiliary motors. The unorthodox design of this rotorcraft is not common in VTOL applications. Figure 2: Gyrodyne 7292 JOURNAL OF CRITICAL REVIEWS ISSN- 2394-5125 VOL 7, ISSUE 19, 2020 Tilt rotor This incorporated the benefits of a helicopter's VTOL system on wings with rotor tilting mounting. The rotor can be inclined beyond 90. This introduction goes beyond helicopter design limitations. The conversion configuration of a tilt rotor engine allows the motors to turn vertically in conditions of starting and landing. It requires a vertical configuration of the motor assembly. It is one of the key drawbacks of the engine. The engine is incredibly strong on its thrust to weight ratio. The very high rotor speed gyroscopic precession imparts immense loads on the motor shaft. Such aircraft are often used with high payload capability in military transport applications as shown in figure 3. Here are some of the most relevant limitations on such aircraft. Figure 3: Tiltrotor Powered lift The name suggests that a powerful elevator with a motor and an electrical elevator fan is mounted to generate the impulse for a safe departure and landing which is depicted in figure 4. An efficient turbofan motor with an after burner design fulfills the flight thrust requirements. The elevator ventilator with equivalent thrust capacity is operated by the turbine bleeding. To balance the down force, auxiliary rolling thrust systems are used. The jet thrust is directed downwards during the departure to generate sufficient lifting power.