1. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Cadet Phase I & II Aerospace Dimensions Aircraft Systems and Airports (Module 2)
Session 1:
Chapter 1 ‘Airplane Systems’
Activity
Additional material for Cadet Officers only
Session 2:
Chapter 2 ‘Airports’
Chapter 3 ‘Aeronautical Charts’
(ONLY for all Cadets that have not yet passed corresponding AE test, and Cadet Mentors)
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

2. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Important Terms (Quiz):
Powerplant
Reciprocating
Cycle
Combustion
Combustion Chamber
Stroke
Compression
Stoichiometric
Rich Mixture
Lean Mixture
Fuel
Meter / Metering
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

3. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Chemistry of Power
A Heat Engine is one that uses Combustion to create Heat Energy, which it then converts into Mechanical Energy
The Combustion occurs when a compressed Fuel/Air mixture is ignited by a spark
The Fuel, Aviation Gasoline (Petroleum Spirit, a Fossil Fuel), is mixed with Air in the Carburetor, then injected into the cylinder and compressed
The ‘ideal’ Fuel/Air mixture is 1/15, called Stoichiometric
More Fuel = Rich Mixture, More Air = Lean Mixture
Normally Rich at start-up, then reduced to typically 1/12
Compression begins the chemical combination process, and makes the combustion more efficient
When ignited, the mixture Oxidizes, releasing Energy BANG!
After ignition, waste gases such as Carbon Dioxide, and Carbon Monoxide, plus water are expelled through the exhaust system
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

4. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
What’s inside a reciprocating engine, and how does it work?
Intake Valve - fuel/air mixture enters here
The Cylinder - fuel is compressed and burned inside
Exhaust Valve - Exhaust gasses out here
Piston - Forced down by explosion, then pushes up and forces exhaust gasses out of the cylinder
Connecting Rod (Con-Rod) - connects piston to crankshaft
Crankshaft - translates piston up/down into shaft rotation, complex shape allows all pistons to work together in sequence
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

5. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Converting Chemical to Mechanical Energy 4 stroke reciprocating engine (5 event):
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

6. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Cylinder Arrangements:
In-Line
Cylinders in a straight line, all facing same way
Horizontally Opposed In-Line
Cylinders in a straight line, facing each other in pairs, con-rods not joined
V In-Line
Two rows of cylinders, matched in pairs angled to form a V when viewed along the crankshaft, con-rods joined
Radial
Complex ‘Star’ cylinder arrangement, con-rods joined
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

7. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Major Parts of an Aircraft Reciprocating Engine (Horizontally Opposed In-Line - External view)
What Cylinder Arrangement do you see?
What does the Starter do?
What does the Carburetor do? What does the Magneto do?
What is the Crankcase for?
Do all the Cylinders operate the same cycle at the same time?
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

8. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Fuel Systems: Aircraft Carburetor
Air is drawn into the engine through the carburetor (due to piston suction), and flows through a Venturi
The Venturi causes the air to accelerate, and thus, due to Bernoulli's principle, the pressure drops
The pressure drop sucks gasoline into the airflow
Mixture Control ensures that the mixture which enters the cylinder is the correct mix of fuel and air
Nozzle ‘Atomizes’ the mixture (very fine mist), which makes combustion much more efficient
Throttle opens/closes a valve to control the amount of mixture which can enter the cylinders
When necessary, the Carburetor Heat function uses Hot Exhaust gasses to melt any ice in the Venturi
Throttle and Mixture can be controlled from the cockpit
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

9. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Jet Engines
Air drawn in and compressed by Compressor fans
mixed with fuel and ignited in Combustion Chamber
Hot Exhaust exits Combustion Chamber as high speed and drives Turbine, which via Shaft drives compressor
In Exhaust Nozzle thrust transfers to aircraft via Thrust Cone
Rocket Engines (Liquid type)
Pumps draw liquid Oxidizer and Fuel into the Combustion Chamber via the Injectors
The Mixture is ignited, expands extremely rapidly, exiting through the ‘Bell’ Nozzle
The nozzle transfers the exhausts thrust to the rocket body
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

10. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Electrical Systems
An aircraft engine typically generates electrical power, as well as driving the propeller, and so is called a Powerplant
Electric power for the spark plugs is generated by the Magnetos, which work like a motor in reverse, by generating an electric current when their internal components are rotated
Modern aircraft have a battery to get this started, but it is possible to have a working electrical system for the combustion spark with NO battery at all!
Electrical power for the aircraft’s equipment (radio, lights etc.) is supplied by the Alternator, which works just like the magneto, but supplies a much lower AC voltage (14-28 volts), and also recharges the battery (needed for starting & electrical power when engine off)
Electrical Current Flow is monitored by the Ammeter
The Master Switch can cut off/turn on the electrical system
Electric current is distributed through the Bus, and individual accessories/systems can be isolated by a series of Circuit Breakers
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

11. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Engine Instruments
The pilot needs to know if a problem develops in the engine, BEFORE it stops working
Since the engine contains oil it is possible to identify leaks and heating problems by measuring Oil Pressure and Oil Temperature
These are shown on a Gauge in the cockpit:
Without gears, Engine Speed = Propeller Speed, so it is extremely important to know what the engine speed is
This is shown in the cockpit by the Tachometer in Revolutions per Minute:
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

12. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Flight Instruments
The Pitot-Static System (Pressure Differential)
Altimeter - Since the pressure at different altitudes is known, by measuring the actual outside pressure, the altimeter is calibrated to show high high up you are
Vertical Velocity Indicator - The rate at which the pressure changes is used to indicate how quickly you are going up or down
Airspeed Indicator - Measures the difference in speed between still air and the Relative Wind, thus showing your Airspeed, Note: this is NOT True Airspeed or Ground Speed
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing

13. Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing
Airplane Systems
Flight Instruments
Gyro Power: A Gyro is a spinning rotor mounted on an axle and allowed to move in 3-Dimensions by a gimbal system
Due to a principal called ‘Rigidity in Space’, once spinning the Gyro will strongly resist any attempt to change its orientation
By comparing the difference between what the aircraft is doing, and the orientation of the gyro, you can measure and display several useful flight characteristics:
Attitude Indicator - shows a stable ‘Artificial Horizon’
Turn Coordinator - shows Roll and Yaw indication. Inclinometer (Ball in Liquid filled tube) shows ‘slip’
Heading Indicator - shows any change of ‘compass heading’
Dr. R.A. Bartholomew Civil Air Patrol, New Jersey Wing