Reciprocating Induction and Engine Cooling Systems

Study Materials

AMT-P, FAA-H-8083-32, AC 43.13-1

Typical Oral Questions

  1. Where is the heat taken from that is used to heat the induction air in a reciprocating engine?

    From a muff that is installed around some part of the exhaust system.

  2. Where does the alternate air come from that is used with a pressure carburetor or a fuel injection ­system?

    From inside the engine cowling.

  3. Where does carburetor ice normally form in a carburetor?

    In the throat of the carburetor, on and around the throttle valve.

  4. Does the application of carburetor heat cause the air-fuel mixture to become richer or to become leaner?

    Heated air causes the air-fuel mixture to become richer.

  5. What is used to drive most of the external superchargers used on modern reciprocating engines?

    Exhaust gases.

  6. What controls the speed of a turbocharger com­pressor?

    The amount of exhaust gas that is forced to flow through the turbine. This is controlled by the position of the waste gate.

  7. What is the danger of operating an aircraft reciprocating engine with too high a carburetor air temperature?

    Too high a carburetor air inlet temperature can cause the air-fuel mixture to reach its critical temperature and detonate.

  8. What is usually installed in a large reciprocating engine between the turbosupercharger and the carburetor?

    An intercooler. This is an air-to-air heat exchanger.

  9. In what position should the carburetor heat control be placed when starting a reciprocating engine?

    In the COLD position.

  10. How does an engine air inlet vortex destroyer help prevent foreign object damage to the engine?

    A high-velocity stream of compressor bleed air is blown out in front of the engine to break up the vortices that form in front of the engine when it is operating at high power on the ground.

  11. What is meant by pressure cooling of an aircraft engine?

    Air cooling in which air is forced to flow through baffles and cylinder fins by a pressure differential across the engine.

  12. What is the purpose of an augmentor tube in the cooling system of an aircraft reciprocating engine?

    The augmentor tube uses the velocity of the exhaust gases to produce a low pressure on one side of the engine that helps pull cooling air through it.

  13. Where is the highest temperature located in a turbine engine?

    At the inlet to the high-pressure turbine.

  14. How are the turbine inlet guide vanes and the first-stage turbine blades in some turbine engines cooled?

    High-pressure compressor bleed air flows through the hollow guide vanes and hollow turbine blades.

  15. Which side of an air-cooled engine cylinder has the greatest amount of cooling fins?

    The side of the cylinder in which the exhaust valve is located.

  16. What should be done to repair a bent cooling fin in a cast aluminum cylinder head?

    It is normally best to leave a bent cast fin alone if it does not restrict the flow of air. Cast fins are brittle and could break off.

  17. What is used in a helicopter to increase the amount of cooling air that flows over the engine cylinders?

    A belt-driven fan.

  18. What should be the position of the cowl flaps on a reciprocating engine when it is run on the ground?

    They should be wide open when operating the engine on the ground.

  19. What is the function of the majority of the air that passes through a turbine engine?

    Most of the air is used for cooling.

  20. How does metallic sodium in an exhaust valve aid in transferring heat?

    The sodium melts when the engine is running, and it sloshes up and down as the valve operates. The sodium picks up heat from the valve head and carries it into the stem so it can be transferred to the cylinder head and dissipated into the air.

  21. How is the structure around a turbine engine protected from excessive heat from the engine?

    An insulating blanket protects the structure from excessive heat.

  22. What is the function of blast tubes that are installed in a pressure cooling system of a reciprocating engine?

    These blast tubes direct cooling air to the magnetos and the generator.

  23. Of what material is the insulation blanket made that is used to protect the aircraft structure from the heat produced by a turbine engine?

    Fiberglass sandwiched between sheets of metal foil.

Typical Practical Projects

  1. Demonstrate to the examiner the correct way to clean the carburetor air filter for an aircraft engine.
  2. Inspect a carburetor heater air box, and explain to the examiner the things that should be checked.
  3. Demonstrate to the examiner the things that should be inspected on a turbocharger installation.
  4. Inspect the induction system of a reciprocating engine for condition. Explain to the examiner the things that could cause a loss of engine power.
  5. Locate and identify the components in the control system of a turbocharger.
  6. Explain to the examiner the correct way to check the operation of a turbocharger system on an aircraft engine.
  7. Using a diagram of a turbocharger installation, explain to the examiner the operation of the type of controller that is installed.
  8. Using a diagram of the clutch system of a two-speed internal supercharger, explain to the examiner the way the clutches operate to change the speed of the impeller.
  9. Explain to the examiner the correct way to use a two-speed supercharger to maintain the maximum engine power as the airplane gains altitude.
  10. Explain the way an induction system fire should be extinguished in an aircraft reciprocating engine.
  11. Examine the baffles in a reciprocating engine installation. Explain to the examiner the things in the baffle system that could cause engine damage.
  12. Using the proper reference materials, repair damaged fins on an air-cooled engine cylinder.
  13. Inspect the cowl flap system of an air-cooled engine and determine whether or not the flaps reach their fully open and fully closed positions.
  14. Using a drawing of the augmentor system installed on a reciprocating engine, explain to the examiner the way this system aids in the cooling of the engine.
  15. Explain to the examiner the correct way to inspect the cooling fan and baffles installed with a helicopter engine.
  16. Explain to the examiner the correct way to inspect the insulating blanket around a turbine engine.
  17. Using a drawing of the cooling system of a turbine engine, explain to the examiner the way cooling air removes heat from the engine.
  18. Inspect an air-cooled engine cylinder, and explain to the examiner the things that would indicate that the cylinder has been improperly cooled.

[10-2024]