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Warm-Up – 1/24 – 10 minutes Utilizing your notes and past knowledge answer the following questions: Describe three main purposes of the aircraft powerplant? List the various means engine designs can be classified. What is a major disadvantage of an inline engine? Describe a major advantage of a horizontally opposed aircraft powerplant? Describe the four stroke sequence of a four stroke reciprocating engine?
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Questions / Comments
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Warm-Up – 1/24 – 10 minutes Utilizing your notes and past knowledge answer the following questions: Describe three main purposes of the aircraft powerplant? List the various means engine designs can be classified. What is a major disadvantage of an inline engine? Describe a major advantage of a horizontally opposed aircraft powerplant? Describe the four stroke sequence of a four stroke reciprocating engine?
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Aircraft Systems Powerplant
An aircraft engine, or powerplant, produces thrust to propel an aircraft. Reciprocating engines work in combination with a propeller to produce thrust. These powerplants also drive the various systems that support the operation of an aircraft.
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Warm-Up – 1/24 – 10 minutes Utilizing your notes and past knowledge answer the following questions: Describe three main purposes of the aircraft powerplant? List the various means engine designs can be classified. What is a major disadvantage of an inline engine? Describe a major advantage of a horizontally opposed aircraft powerplant? Describe the four stroke sequence of a four stroke reciprocating engine?
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Powerplants Reciprocating Engines
Engine designs can be further classified as: Cylinder arrangement with respect to the crankshaft—radial, in-line, v-type, or opposed. Operating cycle—two or four. Method of cooling—liquid or air.
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Warm-Up – 1/24 – 10 minutes Utilizing your notes and past knowledge answer the following questions: Describe three main purposes of the aircraft powerplant? List the various means engine designs can be classified. What is a major disadvantage of an inline engine? Describe a major advantage of a horizontally opposed aircraft powerplant? Describe the four stroke sequence of a four stroke reciprocating engine?
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Powerplants Reciprocating Engines
In-line engines have a comparatively small frontal area, but their power-to-weight ratios are relatively low. In addition, the rearmost cylinders of an air-cooled, in-line engine receive very little cooling air.
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Warm-Up – 1/24 – 10 minutes Utilizing your notes and past knowledge answer the following questions: Describe three main purposes of the aircraft powerplant? List the various means engine designs can be classified. What is a major disadvantage of an inline engine? Describe a major advantage of a horizontally opposed aircraft powerplant? Describe the four stroke sequence of a four stroke reciprocating engine?
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Powerplants Reciprocating Engines
These engines always have an even number of cylinders, since a cylinder on one side of the crankcase “opposes” a cylinder on the other side. The majority of these engines are air cooled and usually are mounted in a horizontal position when installed on fixed-wing airplanes..
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Warm-Up – 1/24 – 10 minutes Utilizing your notes and past knowledge answer the following questions: Describe three main purposes of the aircraft powerplant? List the various means engine designs can be classified. What is a major disadvantage of an inline engine? Describe a major advantage of a horizontally opposed aircraft powerplant? Describe the four stroke sequence of a four stroke reciprocating engine?
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Powerplants Reciprocating Engines
In a four-stroke engine the conversion of chemical energy into mechanical energy occurs over a four stroke operating cycle. The intake, compression, power, and exhaust processes occur in four separate strokes of the piston.
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Questions / Comments
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THIS DAY IN AVIATION January 24
In French pilots Paul Condos and Henri Robida land in Paris after flying from Hanoi in French Indochina in a record time of 3 days 4 hours.
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Questions / Comments
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January 2014 1 2 3 4 5 6 Chapter 5 Flight Controls
Sunday Monday Tuesday Wednesday Thursday Friday Saturday 1 2 3 4 5 6 Chapter 5 Flight Controls Primary Flight Controls 7 8 Ailerons Adverse Yaw Elevators Stabilators 9 10 Quiz 11 12 13 14 Canards Flaps 15 16 Trim Systems Autopilot Chapter TEST Grades Due 17 NO SCHOOL 18 19 20 21 22 Chapter 6 Aircraft Systems 23 24 25 26 27 28 29 30 31
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Questions / Comments
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Chapter 6 – Aircraft Systems
FAA – Pilot’s Handbook of Aeronautical Knowledge
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Today’s Mission Requirements
Identify in writing the primary systems found on most aircraft. Describe the basic operation and characteristics of the primary aircraft systems. EQ: Describe the importance of Aeronautical Knowledge for the student pilot learning to fly.
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Aircraft Systems Propeller
The propeller is a rotating airfoil, subject to induced drag, stalls, and other aerodynamic principles that apply to any airfoil. The engine power is used to rotate the propeller, which in turn generates thrust very similar to the manner in which a wing produces lift.
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Aircraft Systems Propeller
The reason for the twist is to produce uniform lift from the hub to the tip. As the blade rotates, there is a difference in the actual speed of the various portions of the blade.
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Aircraft Systems Propeller
The tip of the blade travels faster than the part near the hub, because the tip travels a greater distance than the hub in the same length of time.
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Aircraft Systems Propeller
Fixed-Pitch Propeller A propeller with fixed blade angles is a fixed-pitch propeller. The pitch of this propeller is set by the manufacturer and cannot be changed.
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Aircraft Systems Propeller
Since a fixed-pitch propeller achieves the best efficiency only at a given combination of airspeed and rpm, the pitch setting is ideal for neither cruise nor climb. The fixed-pitch propeller is used when low weight, simplicity, and low cost are needed.
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Aircraft Systems Propeller
There are two types of fixed-pitch propellers: climb and cruise. The climb propeller has a lower pitch, therefore less drag. Less drag results in higher rpm and more horsepower capability, which increases performance during takeoffs and climbs, but decreases performance during cruising flight.
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Aircraft Systems Propeller
The cruise propeller has a higher pitch, therefore more drag. More drag results in lower rpm and less horsepower capability, which decreases performance during takeoffs and climbs, but increases efficiency during cruising flight.
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Aircraft Systems Propeller
In a fixed-pitch propeller, the tachometer is the indicator of engine power. A tachometer is calibrated in hundreds of rpm and gives a direct indication of the engine and propeller rpm. The instrument is color coded, with a green arc denoting the maximum continuous operating rpm.
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Aircraft Systems Propeller
The rpm is regulated by the throttle. The higher the tachometer reading, the higher the power output of the engine.
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Aircraft Systems Propeller
When operating altitude increases, the tachometer may not show correct power output of the engine. For example, 2,300 rpm at 5,000 feet produces less horsepower than 2,300 rpm at sea level because power output depends on air density. Air density decreases with altitude.
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Aircraft Systems Propeller
As altitude changes, the position of the throttle must be changed to maintain the same rpm. As altitude is increased, the throttle must be opened further to indicate the same rpm as at a lower altitude.
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Aircraft Systems Propeller
Adjustable-Pitch Propeller A constant-speed propeller is a controllable-pitch propeller whose pitch is automatically varied in flight by a governor maintaining constant rpm despite varying air loads.
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Aircraft Systems Propeller
The main advantage of a constant-speed propeller is that it converts a high percentage of brake horsepower (BHP) into thrust horsepower (THP) over a wide range of rpm and airspeed combinations. A constant-speed propeller is more efficient than other propellers because it allows selection of the most efficient engine rpm for the given conditions.
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Aircraft Systems Propeller
An aircraft with a constant-speed propeller has two controls: the throttle and the propeller control. The throttle controls power output and the propeller control regulates engine rpm. This in turn regulates propeller rpm which is registered on the tachometer.
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Aircraft Systems Propeller
Once a specific rpm is selected, a governor automatically adjusts the propeller blade angle as necessary to maintain the selected rpm. As long as the propeller blade angle is within the constant-speed range and not against either pitch stop, a constant engine rpm will be maintained.
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Aircraft Systems Propeller
On aircraft equipped with a constant-speed propeller, power output is controlled by the throttle and indicated by a manifold pressure gauge. The gauge measures the absolute pressure of the fuel/air mixture inside the intake manifold and is more correctly a measure of manifold absolute pressure (MAP).
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Aircraft Systems Propeller
At a constant rpm and altitude, the amount of power produced is directly related to the fuel/air flow being delivered to the combustion chamber. As the throttle setting is increased, more fuel and air flows to the engine and MAP increases.
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Aircraft Systems Propeller
The manifold pressure gauge is color coded to indicate the engine’s operating range. The face of the manifold pressure gauge contains a green arc to show the normal operating range, and a red radial line to indicate the upper limit of manifold pressure.
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Aircraft Systems Propeller
For any given rpm, there is a manifold pressure that should not be exceeded. If manifold pressure is excessive for a given rpm, the pressure within the cylinders could be exceeded, placing undue stress on the cylinders.
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Aircraft Systems Propeller
If repeated too frequently, this stress can weaken the cylinder components and eventually cause engine failure. As a general rule, manifold pressure (inches) should be less than the rpm.
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Aircraft Systems Propeller
When power settings are being decreased, reduce manifold pressure before reducing rpm. When power settings are being increased — increase rpm first, then manifold pressure.
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Aircraft Systems Propeller
Avoid operation at maximum rpm and low manifold pressure. The engine and/or airframe manufacturer’s recommendations should be followed to prevent severe wear, fatigue, and damage to high-performance reciprocating engines.
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Class Summary - Propellers
The propeller is a rotating airfoil, subject to induced drag, stalls, and other aerodynamic principles that apply to any airfoil. Types of propellers include: Fixed pitch and adjustable
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Class Summary - Propellers
Understanding the control and interaction of the throttle pitch are critical Two instruments covered include the tachometer and the manifold pressure indicator
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Questions / Comments
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Lesson Closure - 3 – 2 - 1 2. List 2 things you have questions about today’s lesson. 3. List 3 things you learned today. 1. Create (1) quiz question with answer about today’s lesson.
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