Regional Gliding School Problems With The Fuel System n Very rapid and violent burning of the fuel in the cylinder. n Causes overheating and damage to the metal of the engine. n Signs: –rapid rise in cylinder pressure, and –rapid increase in cylinder head temperature. Detonation:

Regional Gliding School Problems With The Fuel System n Causes: –incorrect fuel, –overheating (lack of airflow), and –the setting a mixture that is too lean. n Can be solved temporarily by making the mixture richer and permanently by using fuel of the octane rating specified by the engine manufacturer.

Regional Gliding School n Premature burning of fuel mixture due to glowing carbon particles or “local hotspots”. n Often confused with detonation. n Experienced when attempting to start a hot engine and usually results in a backfire. n Can do severe damage including warped pistons, and cracked cylinder heads. Problems With The Fuel System Pre-Ignition:

Regional Gliding School n Occurs in the fuel line. n Caused by high atmospheric temperatures, causing the fuel to vaporize and block the flow of liquid fuel in the line. Problems With The Fuel System Vapour Lock:

Regional Gliding School Ignition System n The function of the ignition system is to supply a spark to ignite the fuel/air mixture in the cylinders. n It consists of: ¬two magnetos, ­two spark plugs per cylinder, ®ignition leads, and ¯a magneto switch.

Regional Gliding School The Magneto J If a coil of wire is rotated in a magnetic field, current will be induced in the coil. J This experiment demonstrates the inseparability of magnetism and electricity. J While the design of the magneto is slightly different from that discussed above, the principle is the same.

Regional Gliding School The Magneto J Serves three functions: Êgenerates a low tension current, Ëtransforms this to a high tension, and Ìdistributes the current to the individual spark plugs at the exact time it is desired to have them fire.

Confirmation Stage NOTE: You must use the buttons in the Confirmation Stage

Regional Gliding School Aero Engines Fuel problems, Ignition, and Basic Electrical System A B C D Prevents overheating Connects distributor to spark plug None of the above Let's try a few review questions on Aero Engines: Question #1 - What does the magneto do? Generates a low tension current

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Regional Gliding School A B C D Too lean a mixture Incorrect oil Both A and B Let's try a few review questions on Aero Engines: Question #2 - Name a cause of detonation? Too rich a mixture Aero Engines Fuel problems, Ignition, and Basic Electrical System

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Regional Gliding School Dual Ignition ñ Modern aero engines are fitted with two spark plugs per cylinder and two magnetos. ñ One magneto fires one of the spark plugs for each cylinder, while the second magneto fires the second spark plug for each cylinder. ñ Purpose is two fold: 1safety: if one system fails, the engine will still operate, and 2performance: improves combustion

Regional Gliding School Magneto Switch b The magneto switch has four settings: Àleft, Áright, Âboth, and Ãoff. b To check magnetos, pilot watches RPMs as he/she turns switch. b In the event of rough operation, the pilot can switch to the smoothest operating magneto.

Regional Gliding School Shielding n The parts of the ignition system are surrounded with metal covering which is grounded. n This design is known as shielding and is used to prevent interference with the radio.

Regional Gliding School Ignition Timing n The timing of the magneto to fire the spark plug at the proper time. n Firing too early can result: –in loss of power, –pre-ignition, –piston burning, –scored cylinders, and –broken rings.

Confirmation Stage NOTE: You must use the buttons in the Confirmation Stage

Regional Gliding School A B C D Longer engine life Prevent overheating Both A and C Let's try a few review questions on Aero Engines: Question #3 - What is the purpose of dual ignition? Safety Aero Engines Fuel problems, Ignition, and Basic Electrical System

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Regional Gliding School A B C D Surrounds cockpit Fire wall Metal covering Let's try a few review questions on Aero Engines: Question #4 - What is shielding? Improves combustion Aero Engines Fuel problems, Ignition, and Basic Electrical System

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Regional Gliding School Electrical System F Supplies power to start the airplane. F Also required to operate a multitude of controls including: –flaps, –undercarriage, –all radios, –lights, etc. G Includes everything that operates electrically, except the magnetos. G The ignition system is not connected with the airplane’s electrical system.

Regional Gliding School Components   Storage Battery: – –stores electrical energy required for engine starts. · · Master Switch: – –overall on/off switch for the electrical system. ¸ ¸ Starter Motor: – –turns the engine over after it receives current from the battery.

Regional Gliding School Components   Generator/Alternator: – –supplies current to the system and recharges the battery, – –driven by the engine, – –once motor is started, the alternator will take over and transfer the energy. Î Î Voltage Regulator: – –prevents the system from being overloaded and the battery from overcharging.

Regional Gliding School Components   Bus Bar: – –receives from the battery and the generator (or alternator) and distributes it to various circuits. ¼ ¼ Circuit Breakers: – –prevents component damage resulting from system overloads. ½ ½ Ammeter/Voltmeter: – –indicates current and voltage storage and drain of the system.

Regional Gliding School Components   Generator Warning Light: – –indicates only of generator failure, and – –aircraft without ammeter/voltmeters have this.

Confirmation Stage NOTE: You must use the buttons in the Confirmation Stage

Regional Gliding School A B C D Voltage regulator Circuit breaker Ammeter Let's try a few review questions on Aero Engines: Question #5 - What prevents component damage resulting from system overloads? Bus bar Aero Engines Fuel problems, Ignition, and Basic Electrical System

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Regional Gliding School A B C D Alternator Bus bar Ammeter Let's try a few review questions on Aero Engines: Question #6 - What stores electrical energy for engine starts? Battery Aero Engines Fuel problems, Ignition, and Basic Electrical System

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Regional Gliding School Congratulations!! You have now completed the Fuel Problems, Ignition, and Basic Electrical System lesson of the Aero Engines Module. Of course, this lesson is always available to you for future reference if required. You are now ready to move along to the next Aero Engines lesson you have not completed or to any other module you wish. You can advance to the Self Test Module if you feel ready to challenge the final exam. Good Luck! Aero Engines Fuel problems, Ignition, and Basic Electrical System