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

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

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

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

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

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

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

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

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

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

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

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

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