Cadet Phase I & II Aerospace Dimensions Aircraft Systems and Airports (Module 2)

1. Cadet Phase I & IIAerospace DimensionsAircraft Systems and Airports (Module 2) Session 1: Chapter 1 ‘Airplane Systems’ Activity Additional material for Cadet Officers only Session 2: Chapter 2 ‘Airports’ Activity Chapter 3 ‘Aeronautical Charts’ Activity (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. 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. 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. 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. Airplane Systems • Converting Chemical to Mechanical Energy4 stroke reciprocating engine (5 event): Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

6. 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. 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. 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. Airplane Systems • Jet Engines • Air drawn in and compressed by Compressor fans • mixed with fuel and ignited in Combustion Chamber • Hot Exhaust exits Combustion Chamberas 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 Fuelinto 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. 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. 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. 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. 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