Bonus Episode - The Helicopter

The potted history of the most versatile aircraft ever invented. The Helicopter

Short run or landing, Gyro copters need a run up and short landing. The helicopter was capable of vertical take off and landing from unprapared stips and fields.

They don't need great expanses of land like airfields. They can multitask - transport cargo (some underslung), can be armed with machine guns and mix of these, carry troops. They can eve transport passengers in comfort to sports events or even on and off yachts. Its not just the Navy that have helicopters on their ships.

Transcript

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Hello and welcome to this podcast, A Potted History of the Helicopter, a modern versatile flying machine for both business and pleasure. Leonardo da Vinci designed a flying machine of sorts in 1500, inspired by the Greek word meaning helix or spiral. He made a model. No one knows whether it actually flew. From then, nothing really happened except for the development of fixed wing aircraft. First road aircraft that looked remotely like a helicopter was the Oto Gyro. This was made by Spanish engineer Juan de la Sierra in 1923. The Oto Gyro could fly at low speeds. It was powered by an engine and propeller at the front. And a free rotating rotor blade on top. The free rotating rotor blades span with the forward motion of the aircraft and developed enough lift to help the small wings fitted through the fuselage get the aircraft into the air. This developed it into what we now know as a gyrocopter. Although the engine position has changed, it's now at the back. It still remains the free wheeling rotor head. Fly at very low speeds and can land in very short distances, but not quite as vertically as a helicopter. The first practical helicopter was the Fokker Off-61, built in 1936, and fully controllable. And it was powered by one engine, but had two sets of rotor blades on either side of the fuselage. In place of wings. This led to the first production helicopter, the Fokker Gellis FA 223 Draca or Dragon. A passenger or cargo carrying helicopter that first flew in 1938. Production was halted due to Allied strategic bombing during the war. Only about twenty were finally assembled. However, the helicopter as we know it today was made in 1942 in the USA. It was designed and built by Russian emigre Igor Sikorsky, known as Sikorsky R4. It was used as a rescue helicopter in Burma in 1944. Other uses for it were ferrying parts between locations in the mountains. It was limited to what it could do because of the engine power and the space in the aircraft itself. However, it showed its potential. The Royal Air Force and Royal Navy even purchased the model and called it the hoverfly. The Royal Navy even fitted a helipad to a ship and demonstrated the first deck landings by a helicopter. The helicopter showed it could take off and land vertically, fly forwards, fly backwards, and fly sideways. This made helicopters ideal for small or confined spaces. Designers played with different ideas on designs of the helicopter, namely how many rotorheads they were going to have. Some had four, known as a quadcopter, which is now more popular with drones. And then there's the twin rotorhead helicopters, popular with the military for transport, also becoming popular with companies for firefighting, due to the helicopter's ability to land in restricted spaces, but also the capacity to carry a large volume of fire suppressant. The most common just have one rotor head. However, nearly all helicopters have a tail rotor of some form. The twin rotorhead helicopters counteract each other. In a single rotorhead helicopter, it didn't have a tail rotor. The fuselage was spin. Some single rotor headed helicopters actually have two sets of blades on the same head. This counteracts the tendency of the torque to spin the fuselage in the opposite direction. Instead of having a rotor blade on the tailboom, some helicopters actually have a jet engine. I call it no tar, no tail rotor. This could be seen as being safer, as there's less risk of damage if you walk underneath it while it's running. Another design for the tail rotor is the fenstrom. Integral in the tail, it actually leads to a very clean design. However, like a tail rotor, it is very dangerous when the engine is running. Modern design is brought onto an aircraft, which is a cross between a fixed wing and a helicopter. It takes off vertically like a helicopter, and when it gets to height, the wings rotate horizontally. Then it becomes a fixed wing aircraft. Its primary use is with the military. This aircraft is ideal for light transport and using the helicopter's ability to get in and out of restricted areas is ideal for the military. However, there are civilian versions being designed as well. Unlike fixed-wing aircraft where number of engines can be up to eight in some cases, with a helicopter it's really only to three. You have a single engine, twin engine, and even a three engine, generally military aircraft. Single engine are light transport and ideal for training. Then you'll get the twin engines, which are more for commercial and charter and such like. Search and rescue by Coast Guards has brought back the helicopter's initial history for when it was doing search and rescue in the mountains of Burma. It now does search and rescue off the coast of countries over the Atlantic, Pacific, and in some countries in mountains. As with fixed wing aircraft, helicopters have their roles as well. With military helicopters, the roles can include solely transport, solely attack, but they can also include attack and transport helicopters, not forgetting the training helicopters. With civilian helicopters, you have the training aircraft, and you have the light transport aircraft, and you also have the passenger helicopters, especially when it comes to ferrying people out to oil rigs in the North Sea and such places. You also have the aircraft for charter. Someone wishes to go to a sporting event, they can charter an aircraft, take their friends with them. The helicopter can get them close to that event without using public transports or get stuck in traffic jams. A popular myth about helicopters is that they crash if the engine fails. They, like fixing, can actually glide. As the air moves through the freewheeling rotor blades, this causes an element of lift. The aircraft is going fast enough, this will slow the descent of the aircraft, a bit like a sycamore leaf in nature. With the ownership of a helicopter comes more technical and more regular maintenance, but their usefulness outweighs this drawback. Rule of thumb for cost of learning to fly a basic helicopter is twice that of the equivalent fixed wing aircraft. Flying helicopter, there's a popular saying, giving an idea on the difficulty of flying the helicopter, and that's to tap your head and rub your stomach at the same time. There are of course differences with the controls of a helicopter. They have the rudder pedals, which do the tail rotor, and they have a cyclic stick, which is in essence the main stick that a fixed wing aircraft has. But they also have the collective lever, which is usually on the pilot's left hand side. The cyclic stick is used similar to conventional aircraft, moving it left, right to pitch up and down. The rotating blades, in effect, creates a rotating wing. The collective lever is used to adjust the power and to adjust the angle of the individual blades. This is what makes the helicopter climb and descend. This is also where the throttle is located. Just on a point of note, in a fixed wing aircraft, the captain generally sits on the left hand side. That's viewed from behind, for instance, in your airliner. In a helicopter, the captain is generally on the right hand side. Or left hand if viewed from outside. There are, however, a few exceptions to that rule. Thank you for listening to the pocket history of the helicopter. Like and subscribe, and I will speak to you on the next one.