3. Regional Gliding School Cooling System ëIn an internal combustion engine, fuel is burned, resulting in the production of a tremendous amount of heat. ëThis heat is distributed across the engine and absorbed by the metal. ëWithout some sort of engine cooling, this heat would result in warping which would end in engine failure.

4. Regional Gliding School ìSome airplanes use liquid coolant. ìThe most common method of dissipating engine heat is by circulating cooler air around the engine cylinders. ìHorizontally opposed and radial engines are air-cooled. ìSome in-line engines are air-cooled; a few are liquid cooled.

5. Regional Gliding School Parts of an air Cooling System –Added to the external surface of the engine cylinders to provide a greater surface area for heat to be absorbed, –Ram air enters the engine cowls and cools the fins as it passes by, and –Openings in the rear of the cowls expel this air. Fins:Fans: –Gear driven, –Mounted on the front of the engines, and –Assist the flow of cooling air at higher altitudes.

6. Regional Gliding School Parts of an air Cooling System –Also known as jet pumps, –Direct exhaust gases through these tubes, and –Produces a suction strong enough to increase the flow of cooling air past the cylinders. Augmentor Tubes:Cowling Flaps: –Devices that control the size of the openings at the rear of the engine cowls, and –The baffles then force the cooling air around the cylinders.

7. Regional Gliding School Four Functions of Oil Carries away excessive heat generated by the engine. Cooling: Sealing: Provides a seal between the piston rings and cylinder walls, preventing “blow-by” loss of power and excessive oil consumption. Prevents wear and tear of metal parts by maintaining a film to reduce friction. Flushing: Lubrication: Cleans and flushes engine interior of contaminants that enter or are formed during combustion.

8. Regional Gliding School Requirements of a Good Oil ¶Viscosity is the resistance to flow, stickiness or body: ågives proper distribution of oil throughout the engine and prevents rupturing of the oil film, åan oil with a high viscosity index is one in which the changes in viscosity, due to varying operating temperatures, are small, åuse of an oil of too high viscosity will cause high oil pressure, and åuse of an oil of too low viscosity will cause low oil pressure.

9. Regional Gliding School Requirements of a Good Oil ·High flash point: åtemperature beyond which a fluid will ignite, and åshould be in excess of the highest engine temperature. ¸Low carbon content: åto leave as little carbon as possible should oil work past the scraper ring and burn, ågood oil should also have a low wax content, and åoils which have good resistance to deteriorate and the formation of lacquer and carbon deposits are said to have good oxidation stability.

10. Regional Gliding School Requirements of a Good Oil ¹Low pour point: åthe temperature at which a fluid solidifies, and ånecessary for cold weather starting.

11. Regional Gliding School Methods of Lubrication ¬Force feed by dry sump: íoil is contained in a separate tank, íforced under pressure from a pressure pump through the hollow crankshaft to lubricate the engine, ía by-pass around the filter is incorporated to prevent damage in case of failure to clean the filter, and ígauge to monitor oil pressure.

12. Regional Gliding School Methods of Lubrication ­Force feed by wet sump: íoil supply is contained in a sump or pan under the crankcase, íoil passes through a filter into a suction type of pressure pump, ípressure pump is engine driven, and íadvantage: light weight and simple, being free of extra tank, tubing and linkages characteristic of dry sump system, íbut limited by the size and design of the nacelle or cowling.

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

14. Regional Gliding School A B C D Viscosity High Carbon Content Low Pour Point High Flash Point Let's try a few review questions on Aero Engines: Question #1 - What is NOT a requirement of good oil? Aero Engines Cooling, Fuel and Lubrication Systems

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19. Regional Gliding School A B C D Cooling Flushing Force Feed Sealing Let's try a few review questions on Aero Engines: Question #2 - Name a method of lubrication. Aero Engines Cooling, Fuel and Lubrication Systems

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24. Regional Gliding School Fuel System ÛStores and delivers the proper amounts of fuel at the right pressure to meet the demands of the engine. ÛUsually several tanks to store the quantity of fuel required to give the airplane reasonable range. ÛTanks usually located in the wings, although extra tanks may be added. ÛPilot can switch between tanks by way of selector valve.

25. Regional Gliding School Gravity Feed Fuel System KSimplest design. KUsed on many high wing, low powered airplanes. KFuel tanks mounted in the wings above the carburetor. KUses gravity draw fuel from tanks, past fuel selector valve to the carburetor.

26. Regional Gliding School Gravity Feed Fuel System KA drain allows for the removal of water and sediment trapped at the strainer. KA primer sprays raw fuel into the intake manifold system or directly into the cylinders to aid engine starting, particularly in cold weather.

27. Regional Gliding School Fuel Pump Fuel System ûEngine driven fuel pump supplies the pressure that keeps the fuel flowing to the engine. ûUsed in all low wing airplanes and in any airplane with a higher performance engine.

28. Regional Gliding School Fuel Pump Fuel System ûIncorporates a basic pump, auxiliary electric pumps or booster pumps that serve in emergency in case the engine driven pump fails. ûFuel pressure gauge give visual indication that fuel system is working.

29. Regional Gliding School Other Components of the Fuel System ßvary in size, shape and location, ßconstruction material is light and chemically inert to fuel, ßhave a drain at the bottom and have internal baffles to prevent spilling during sudden changes in attitude, and ßthe tops of the tank are vented to maintain atmospheric pressure inside the tank. Fuel tanks:

30. Regional Gliding School Other Components of the Fuel System ßconnect the fuel tanks to the carburetor, ßmade of varying materials, and ßone or several filters present prior to reaching the carburetor. Fuel Lines and Filters: ßthis device permits the pilot to select from which tank he/she wants to draw fuel Fuel Selector Control:

31. Regional Gliding School Fuels *Fuels for modern high compression engines must burn slowly and expand evenly rather than explode quickly. *The fuels that possess this quality are known as high octane fuels.

32. Regional Gliding School *Octane: *a substance which possesses minimum detonating qualities. *Heptane: *a substance which possesses maximum detonating qualities. *The proportion of octane to heptane in a fuel is expressed as a percentage. Fuels Octane Rating:

33. Regional Gliding School Fuel Grades GUsually indicated by two numbers. GThe first number indicates the octane rating at lean mixture conditions and the second at rich mixture conditions. GGrade 80/87: octane rating of 80 at lean mixture conditions and 87 at rich mixture conditions.

34. Regional Gliding School Fuel Grades GOctane numbers only go to 100. GThose above are called Performance Numbers and represent 100% octane with additional additives to slow the burning even more.

35. Regional Gliding School Applications of Various Fuel Grades GLow Power Output: IGrade 80 (or 80/87); Red GMedium Power Output: I100 (High Lead); Green GMedium Power Output: I100 LL (Low Lead); Blue GJet Fuel: IKerosene; Clear or straw

36. Regional Gliding School Additional Notes NIf the proper grade of fuel is not available, always use the next (higher) grade, never the lower one. NThe pilot is responsible to see that the proper fuel is used and this can be found in the airplane flight manual.

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

38. Regional Gliding School A B C D A higher grade Next Higher grade A lower grade Next lower grade Let's try a few review questions on Aero Engines: Question #3 - If the proper grade of fuel is not available, which grade would you use? Aero Engines Cooling, Fuel and Lubrication Systems

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43. Regional Gliding School A B C D Octane cooled Liquid cooled Air cooled Both B and C Let's try a few review questions on Aero Engines: Question #4 - How is cooling of the engine accomplished? Aero Engines Cooling, Fuel and Lubrication Systems

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48. Regional Gliding School Congratulations!! You have now completed the Cooling, Fuel and Lubrication Systems 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 Cooling, Fuel and Lubrication Systems