1. Parts of an Aircraft and Propulsion Systems
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Parts of an Aircraft and Propulsion Systems

2. What is an Airplane? Aircraft Airplane More general term
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
What is an Airplane?
Aircraft
More general term
Refers to any heavier-than-air object that is
Supported by its own buoyancy
Supported by the action of air on its structures
Airplane
Heavier-than-air craft propelled by an engine
Uses aerodynamic surfaces (wings) to generate lift

3. Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
What is an Airplane?
Every airplane is an aircraft, but not every aircraft is an airplane.
Space shuttle
Gliders
Helicopters
Space Shuttle – No engines for propulsion
Gliders – No engines
Helicopters – Aerodynamic surfaces are not fixed. They rotate.

4. Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Why So Many Types?
Every modern aircraft is built for a specific purpose.
Different altitudes
Different speeds
Different weight-carrying capacities
Different performance

5. Why So Many Types? Jet fighters Passenger airplanes
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Why So Many Types?
Jet fighters
Relatively lightweight
Highly maneuverable and very fast
Carry small amount of weight, including fuel
Must refuel on long flights
Passenger airplanes
Larger, carry more weight, fly longer distances
Less maneuverable and slower

6. Why So Many Types? Wing types Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Why So Many Types?
Wing types
The characteristic that most readily identifies the type, performance, and purpose of an airplane is the shape of its wings.
Each shape allows for premium performance at different altitudes, different speeds, and different loads which must be carried.

7. Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Why So Many Types?
Speed
The speed of sound is dependent on altitude and atmospheric conditions
Mach is the term used to specify how many times the speed of sound an aircraft is traveling
Subsonic: Less than Mach 1
Transonic: Mach .9 to Mach 1.5
Supersonic: All speeds above Mach 1
Hypersonic: All speeds greater than Mach 5
Another important discriminator between airplanes is speed.
The suffix “sonic” refers to the speed of sound.
Mach 1 is one times the speed of sound. Mach 2 is twice the speed of sound. Mach numbers less than 1 are speeds less than the speed of sound.
Aircraft flying at hypersonic speeds can also be said to be flying at supersonic speeds.

8. Parts of an Airplane Five basic structural components Fuselage Wings
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Five basic structural components
Fuselage
Wings
Empennage (tail structures)
Propulsion system
Undercarriage

9. Fuselage Main body structure Contains
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Fuselage
Main body structure
All other components are attached to it
Contains
Cockpit or flight deck
Passenger compartment
Cargo compartment
Produces a little lift, but can also produce a lot of drag

10. Wings Most important lift-producing part of the aircraft
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Most important lift-producing part of the aircraft
Also carries the fuel
Designed so that the outer tips of the wings are higher than where the wings are attached to the fuselage
Called the dihedral
Helps keep the airplane from rolling unexpectedly

11. Wings Parts of an Aircraft Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Wings

12. Wing Designs Straight Wing Found mostly on small, low-speed airplanes
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Wing Designs
Straight Wing
Found mostly on small, low-speed airplanes
Good lift at low speeds
Not suited to high speeds
Creates a lot of drag because the wing is perpendicular to the airflow
Provides good, stable flight
Cheap and can be made lighter

13. Wing Designs Sweepback Used on most high-speed airplanes
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Wing Designs
Sweepback
Used on most high-speed airplanes
Less drag, but more unstable at low speeds
Amount of sweep depends on the purpose of the airplane
Commercial airliner has moderate sweep
High speed airplanes (e.g., fighters) have moderate sweep
No forward sweep wings are in mass production
A commercial airliner has less drag while maintaining stability at lower speeds.
Fighters are not very stable at low speeds. They take off and descend for landing at a high rate of speed.

14. Wing Designs Delta Wings Looks like a large triangle from above
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Wing Designs
Delta Wings
Looks like a large triangle from above
Can reach high speeds
Landing speeds are very fast
Wing shape found on the supersonic transport Concord

15. Wing Designs Swing Wing
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Wing Designs
Swing Wing
This design combines the high lift characteristics of a straight wing with the ability of the sweepback wing to move at high speeds
During landing and takeoff, wing swings into an almost straight position
During cruise, wing swings into a sweepback
Hinges that enable wings to swing are very heavy

16. Wing Components Trailing edge equipped with flaps
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Wing Components
Trailing edge equipped with flaps
Move backward and downward
Increase the area of the wing and the camber of the airfoil
Different from the ailerons, also located on the trailing edge of the wing
When an airplane lands, it is desirable to fly as slowly as possible. Ideally for landing, an airplane would have a large wing with a very cambered airfoil. However, airfoils designed to perform well at slow speeds are not good for flying at faster speeds, and vice versa. Airplane designers have developed a set of features that allow the pilot to increase the wing area and change the airfoil shape to compensate for this.

17. Empennage Also known as the tail assembly
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Empennage
Also known as the tail assembly
Provides stability and control
Two main parts
Vertical stabilizer (fin) to which the rudder is attached
Horizontal stabilizer to which the elevators are attached

18. Undercarriage Also known as the landing gear, which is made up of
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Undercarriage
Also known as the landing gear, which is made up of
Struts
Wheels
Brakes
Can be fixed or retractable
Many small airplanes have fixed landing gear which increases drag but keeps the airplane lightweight. Larger, faster, and more complex aircraft have retractable landing gear that can accommodate the increased weight. The advantage to retractable landing gear is that the drag is greatly reduced when the gear is retracted. When you fly on a commercial airliner, you will notice that the pilot retracts the landing gear very soon after the airplane leaves the ground. This helps to decrease drag as the airplane ascends.

19. Controls Parts of an Aircraft Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Controls
When a plane is in flight, there are three imaginary axes of rotation. These lines run through the weight center (or center of gravity) of the plane. The airplane’s rotation around the y axis is called yaw; rotation around the x axis is called pitch, and rotation around the z axis is called roll.

20. Controls Roll is controlled by the ailerons
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Controls
Roll is controlled by the ailerons
Used to raise and lower the wings
Turning the control wheel left causes the left aileron to raise and lowers the right aileron.
The plane rolls left.
Turning the control wheel right causes the right aileron to raise and lowers the left aileron.
The plane rolls right.

21. Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Controls
Pitch is controlled by the elevators on the tail of the plane.
They are controlled by the control wheel (i.e., stick).
If the wheel or stick is pulled back, the elevators go up, causing the nose to point up and the plane to climb.
If the wheel or stick is pushed forward, the elevators go down, causing the nose to point down and the plane to lose altitude.

22. Controls Yaw is controlled by the rudder.
Parts of an Aircraft
Gateway To Technology®
Unit 4– Lesson 4.2– Aeronautics
Controls
Yaw is controlled by the rudder.
The right foot pedal turns the rudder to the right.
This action causes the tail to yaw to the left and the nose to yaw to the right.
To smoothly bank a plane or to turn it left or right, the pilot uses the ailerons and the rudder together.

23. Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Propulsion System
A machine that produces thrust to push an object forward
The amount of thrust depends on the mass flow through the engine and the exit velocity of the gas
On airplanes, thrust is usually generated through some application of Newton's third law of action and reaction. A gas, or working fluid, is accelerated by the engine, and the reaction to this acceleration produces a force on the engine.

24. Airplane Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Airplane Propulsion Systems
Propeller
Turbine (jet) engine
Ramjet or
Scramjet
Rocket Planes

25. Why Are There Different Types of Engines?
Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Why Are There Different Types of Engines?
Newton’s 1st Law
Objects in motion tend to stay in motion and objects at rest tend to stay at rest unless something pushes or pulls on the object.
Therefore:
Thrust from the propulsion system must balance the drag when the airplane is cruising.
Thrust from the propulsion system must exceed the drag for the airplane to accelerate.
You must have the correct type of engine (propulsion system) to provide the correct amount of thrust.

26. Aircraft Motion Propulsion Systems Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Aircraft Motion

27. Propulsion System Piston Engines and Propellers
Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Propulsion System
Piston Engines and Propellers
Remember that internal combustion (gasoline) engines require oxygen to ignite the fuel, and therefore need to fly at lower altitudes
Used most commonly on smaller aircraft
They generally fly slower, and at lower altitudes

28. Propulsion System Piston Engines and Propellers Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Propulsion System
Piston Engines and Propellers
A propeller system takes the rotary motion from a motor and converts it into thrust. It has multiple blades attached to a central shaft, and works like a rotating screw or wing. The blades are often airfoil shaped, thus utilizing both Bernoulli’s principle and Newton’s third law to produce forward motion.

29. Airliners and Cargo Planes
Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Airliners and Cargo Planes
Spend most of the time in a cruise state
High engine efficiency and low fuel usage more important than excess thrust
Turboprop and turbofan propulsion used on airliners and cargo planes
Since thrust depends on both the amount of gas moved and the velocity, we can generate high thrust by accelerating a large mass of gas by a small amount, or by accelerating a small mass of gas by a large amount. Because of the aerodynamic efficiency of propellers and fans, it is more fuel efficient to accelerate a large mass by a small amount. That is why we find high bypass fans and turboprops on cargo planes and airliners.

30. Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Propulsion Systems
Jet propulsion is similar to the release of an inflated balloon.

31. Propulsion Systems Turbojet First really useful jet engine built
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Propulsion Systems
Turbojet
First really useful jet engine built
The turbojet was the first really useful jet engine to be built. The air flows into the engine through the air intak. The design of the inlet makes the air slow down and also raises the pressure. The air then goes through the compressor where sets of blades compress the air even more, greatly raising the pressure. The air then enters the combustion chamber where the fuel is added and ignited. The very hot, high pressure air rushes past the turbine blades, making them spin very fast. The turbine blades are connected back to the compressor blades by a shaft. The turbine blades take some of the energy from the air and return it to the compressor. The hot, high pressure air that gets past the turbine "jets" out the exhaust nozzle, thrusting the engine forward.
Turbojets are very inefficient and noisy at subsonic speeds. Most modern plans use turbofans and turboprops.

32. Propulsion Systems Turbofan Turboprop
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Propulsion Systems
Turbofan
Adds a large set of fan blades at the front of the inlet
Turboprop
The fan from turbofan is replaced with a propeller
The fan works much like a propeller, thrusting the engine forward and pushing a large amount of air backwards. As the air is pushed back by the fan, some of it goes into the engine and some bypasses the engine. The engine that sits behind the fan is basically a turbojet. The air that goes into this engine receives the same treatment as the air that goes through the turbojet.
The turboprop engine is essentially a turbofan engine where the fan is replaced by a propeller. The propeller is placed outside of the inlet.

33. Fighter Planes and Hypersonic Aircraft
Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Fighter Planes and Hypersonic Aircraft
Require high excess thrust to accelerate quickly and overcome high drag associated with high speeds
High thrust is more important than engine efficiency

34. Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
A ramjet is a form of jet engine which uses the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot provide thrust at zero airspeed, and therefore, cannot move a plane from standstill. They require a forward speed of at least half the speed of sound (Mach 0.5)
A scramjet or” super combustion ramjet” uses the same principles as the ramjet. However, the minimum functional speed, requires acceleration by other means to hypersonic speed before the scramjet can become active. Ramjets slow the incoming air to a subsonic speed within the combustor. Scramjets require the airflow through the engine to be at hypersonic speed. Both function best at hypersonic (above Mach 3) speeds.
NASA is currently testing the X-43 at speeds of Mach 10.

35. Rocket Powered Airplanes
Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Rocket Powered Airplanes
Uses a rocket engine for propulsion
Has higher speeds
Propels only for a short period of time
Also known as a rocket plane, it is an aircraft that uses a rocket for propulsion, sometimes in addition to air-breathing jet engines (known as Jet Assisted Take Off). They can fly at much faster speeds than a jet aircraft of similar size, but only work for a few minutes, followed by a glide. Because they are powered by a rocket which does not need oxygen from the atmosphere, they are good for very high altitude flight. They also accelerate faster, and therefore have shorter takeoffs.
Unusual launch configurations
From another plane
Vertically – nose in the air and tail to the ground

36. Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Rocket Propulsion
Engine pushes itself forward or upward by producing thrust
A rocket engine uses only propellant carried within it
A rocket can operate in outer space, where there is almost no air
Unlike a jet engine, which draws in outside air, a rocket engine uses only the substances carried within it.
Click on Liftoff to show video of rocket launch.

37. 3 – 2 – 1 Liftoff! Propulsion Systems Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
3 – 2 – 1 Liftoff!

38. How Do Rocket Engines Work?
Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
How Do Rocket Engines Work?
Newton’s 3rd Law:
For every action there is an equal and opposite reaction.
Rocket engines generate thrust by putting a gas under pressure.
The gas escaping the rocket is called exhaust.
As the rocket pushes the exhaust backward, the exhaust pushes the rocket forward.
The vast majority of rockets are chemical rockets. The two most common types of chemical rockets are solid-propellant rockets and liquid-propellant rockets. Engineers have tested a third type of chemical rocket, called a hybrid rocket, that combines liquid and solid propellants. Electric rockets have propelled space probes and maneuvered orbiting satellites. Researchers have designed experimental nuclear rockets.

39. Propulsion Systems
Gateway To Technology
Unit 4– Lesson 4.2– Aeronautics
Image Resources
Microsoft, Inc. (2008). Clip art. Retrieved September 10, 2008, from
National Aeronautics and Space Administration (NASA). (2008). Beginner’s guide to propulsion. Retrieved June 23, 2009, from
National Aeronautics and Space Administration (NASA). (2008). NASA TV Video Gallery. Retrieved June 23, 2009, from
National Aeronautics and Space Administration (NASA). (2008). NASA – A closer look at the X-43 mission. Retrieved June 23, 2009, from
National Aeronautics and Space Administration (NASA). (2007). NASA – Rocket. Retrieved June 23, 2009, from