Technical Description
Tsechok, Yama
Department of English, City College
Spring 2021
ENGL 21007: Writing for Engineering
Professor Sara Jacobson
Outline of the content
Page 3. Introduction
Page 3-4. What is a glider?
Page 6-8. Components
Page 8-9. Instruments
Page 4-6. Three main types of rising air
Page 9. Landing
Page 9-10. Conclusion
Page 11. Self Assessment
Introduction
We’ve come so far to be in the world where we stand today, our world is so technologically advanced that it would’ve only been a dream just a few decades before. As we look up into the blue sky, we can see the white smoke trails left behind as the giant metal birds rumble through the clouds. For many, the science behind this phenomenon is believed to be the direct result of powerful Engines that would provide excessive amounts of force to make such a giant metal bird take off the ground and into the sky. What if I told you this phenomenon is still possible but without the direct use of Engines, for starters, many would absolutely disagree with the idea of even thinking of that and it’s understandable because no one sees a hundred thousand pound object just floating around, but if we use the paper airplane concept, a metal plane flying without an engine is still possible. This concept was first started in 1853 by a British engineer going by the name of George Cayley, he is responsible for creating the world’s first successful glider and his innovation later inspired many more innovators like Otto Lilienthal of Germany and the Wright Brothers of the U.S.
What is a glider?
For starters, a glider is a type of fixed-wing aircraft that is mainly supported by the dynamic reaction of the air acting against its long lifting surfaces and whose free flight does not depend on large engines that other fixed wings depend on. Although a glider does not need an engine to fly through the sky, it still needs a pulling force to get it into the air and that’s where usually the smaller engine aircraft come into play. Pictured below, you can see a small single-engine fixed-wing towing the glider off the runway into the sky.
Another way of getting it airborne is by hoisting it like a kite on a long cable, the cable is pulled along behind a car at a high speed, when the glider is airborne the cable is released. It’s in the air, now what? For a glider to stay airborne, it must produce a sufficient amount of lift to balance its weight, the faster the glider moves through the sky the more lift it produces thus more time in the air. To stay airborne, pilots use a couple of methods to increase flight time with the help of mother nature. Rising air from the surface of the ground helps a glider with an increase in lift.
Three main types of rising air
The three main types of rising air used by glider pilots are Thermal, Ridge Lift, and wave lift.
- Thermals are columns of rising air produced by the heating of the Earth’s surface, the sun heats up the earth’s surface which in turn heats up the air above it, the warm air expands and becomes less dense than the surrounding air, thus making the lighter air rise. Asphalt parking lots and rocky terrains are great examples of places where thermal columns can be located. Thermals can usually be identified by the presence of visible cumulus clouds which have flat bases with a cotton-like appearance. In the picture below, a good representation of how thermal columns work is shown.
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- Ridge lift is also another technique used by gliders to get more flying time in the air. Ridge lift is created when winds blow against mountains, ridges, or hills. When the air collides with the mountain it is redirected up and thus forms a band of lift along the windward side of the slope.
As you can see in the picture, the air hits the side of the mountain and is redirected up, the air then pushes up from under the wing and increases the flight time of the glider.
4 (3) The third technique most widely used by glider pilots is the Wave Lift technique which is very similar to that of ridge lift because they both meet the side of the mountain but the main difference between these two is that Wave Lift is created on the downwind side of the mountain peak. The lift produced by this can reach thousands of feet above ground.
Although these events are very important for a glider to stay airborne none of it will be very effective without the major components acting its part.
Components
Explaining the operations and parts of a glider is much easier than explaining the parts of a traditional aircraft because it has fewer components, it’s smaller in size and it has no engine. Even though it sounds like they are two different types of machines, they still operate pretty similarly. They share some of the most important components which are listed below.
- Aileron – Aileron is one of the three primary flight controls of the aircraft and allows the pilot to roll the aircraft on its longitudinal axis.
- Cockpit – Cockpit or flight deck is the area that is usually forward of the aircraft and is where the pilot controls the aircraft from.
- Empennage – Empennage, also known as the tail section of an aircraft is a structure located at the aft of an aircraft primarily to provide stability during flight. The Empennage is also where the Elevator and the Rudder of the aircraft is attached.
- Elevator – Elevator is one of the three primary flight controls of the aircraft and it allows the pilot to move the plane about the lateral axis of the aircraft.
- Rudder – Rudder is also one of the three primary flight controls of the aircraft and it allows the pilot to move the plane about the vertical axis of the aircraft.
- Fuselage – The fuselage or the body of the airplane is a long hollow tube which holds all the pieces of an aircraft together, The fuselage is also where the passengers sit in the airplane during a flight.
- Landing gear – Landing gear is one of the most crucial parts of an aircraft because it provides a suspension system for the aircraft during taxi, take-off and landing. The landing gear also provides directional control of the aircraft when it is grounded.
- Spoilers – Spoilers are part of the secondary flight controls and are located on the wing, it is deployed primarily to help slow the aircraft down and help it descend.
- Wing – The wing is an airfoil that generates most of the lift of an aircraft.
Instruments
Aside from the major flight controls and components, there is another very important piece of technology in the glider and that is the Instrument panel. The instrument panel houses the instrument gauges needed to understand the aircraft and the current condition of the flight.
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The first instrument you see is the “turn and slip” which lets the pilot know the rate and direction of a turn. The ball in the middle indicates if the glider is rolling sideways. The second gauge you see is called the “Compass” ; it indicates the glider’s direction with respect to magnetic north. The gauge under the “turn and slip indicator” is called the “Airspeed” ; it allows the pilot to know the speed of the glider with respect to the air through which it’s moving. The middle gauge is the “Vertical speed” gauge and it allows the pilot to know the rate of climb of the glider. The last gauge you see is the “Altitude” gauge and it indicates basically as the name suggests the altitude of the glider itself.
Landing
The glider has been up in the air for a while now and needs to land soon, how does the pilot achieve this?, well for starters there are a few key differences between an aircraft landing and a glider landing. The most important being that the aircraft has an engine, which the pilot can engage to increase power if he or she feels that the landing will be short in contrast a glider pilot does not have the option of increasing thrust during landing and so they are all highly trained to judge their landing so that they don’t land short. As mentioned before in the [components] section, a glider pilot will deploy the spoiler during landing so that he or she can slow the glider down and land safely.
Conclusion
At last, with modern technology a lot of things are possible. Many people will take it hard to believe that a metal bird without an engine can take off into the skies but after countless studies and research we are able to make it happen. Planes before could only fly if there was an additional unit on the aircraft itself producing thrust but as time passed and after countless research, we are able to make an aircraft fly through small tweaks and the use of mother nature which makes me believe that honestly anything can be achieved.
Citation
- Fun Facts for Kids on Animals, Earth, History and more! (n.d.). Retrieved May 22, 2021, from https://www.dkfindout.com/us/transportation/history-aircraft/early-gliders/
- Aircraft, Glider Wallpapers HD / Desktop and Mobile Backgrounds. (2017, November 20). Retrieved May 22, 2021, from https://wallup.net/aircraft-glider/
- Lift (soaring). (2021, January 01). Retrieved May 22, 2021, from https://en.wikipedia.org/wiki/Lift_(soaring)#/media/File:Thermal_column.svg
- How gliders fly, and how they’re different from powered aircraft. (n.d.). Retrieved May 22, 2021, from https://www.boldmethod.com/blog/article/2015/02/your-guide-to-glider-flying/
- Lift sources: Soaring society of america: Aviation glider pilot resources. (2021, March 18). Retrieved May 22, 2021, from https://www.ssa.org/lift-sources/
- Time to glide -. (n.d.). Retrieved May 22, 2021, from https://studentglider.com/
