Assessment and quiz questions induction and exhaust

The pressure relief valve activates at what pressure range above max boost?

1 - 1.5 "Hg

The pressure ratio controller prevents UDP from increasing more than what?

2.2 times ambient pressure

Sea-level boosted engines maintain a maximum boost pressure of ________ "Hg

29.92

Boost manifold pressure is generally considered to be any manifold pressure above standard sea level, which is.

29.92Hg

How can a pilot determine if a carburetor is icing?

A drop of RPM or manifold pressure.

What are the differences between a supercharger and a turbocharger?

A turbocharger is run off the exhaust gases as a supercharger is run off of the crankshaft.

At altitudes above a supercharged/turbocharged engine's critical altitude...

Above the critical altitude the horsepower and manifold air pressure will decreases in proportion to the altitude increases.

Where is air pressure the highest in a normally aspirated engine?

Air scoop

If a turbocharger waste-gate is completely open:

All the exhaust gases will bypass the turbine.

Which type of induction system boosts manifold pressure and has two different speed ratios?

Altitude Engine

How can carburetor icing on an engine equipped with a constant speed propeller be detected?

An engine with a constant speed prop will indicate ice by having the RPM stay constant the power will drop along with the manifold pressure.

Mufflers use __________ to break up sound energy.

Baffles

Why is Carburetor heat not generally used during takeoff unless absolutely necessary?

Because the carburetor heat increases the air temperature going into the engine making the air less dense which reduces the power of the engine. Also can cause detonation.

What is bootstrapping?

Bootstrapping occurs when a turbocharger senses a small change in temp or speed or both and continually changes the turbocharger output in an attempt to establish an equilibrium.

How can carburetor icing on an engine be detected?

By a fixed pitch prop, constant speed prop or a carburetor air temp gauge.

What is a hot spot?

Can exist in the exhaust manifold pressure causing uneven gases to flow which can result in decreasing in the exhaust manifold pressure.

What is used to turn the turbine wheel on a turbocharger?

Exhaust Air

What is the component on the exhaust system of some engines that increases airflow through the engine cowling to aid in cooling?

Exhaust augmenters

What are the three turbocharger regulating components of a sea-level boosted turbocharger system?

Exhaust bypass valve assembly, density controller and differential pressure controller.

A turbo compound system uses exhaust gasses to drive a turbine that is couples to a supercharger.

False

The primary purpose of the air induction system is to provide air in sufficient quantity and temperature to support normal combustion.

False

The turbine wheel and the compressor wheel share a common shaft within the turbocharger and spin independently on their own bearings.

False

Which types of air filters are used on aircraft?

Flock, paper cartridges and polyurethan foam.

When MAP is increased ______ is increased.

Horsepower

What does an increase in manifold pressure when carburetor heat is applied indicate?

If the carburetor heat is applied and the manifold pressure increases, it indicates that there was carburetor ice on an aircraft with a constant speed prop.

What are the different types of intake icing?

Impact icing, throttle icing, and fuel evaporation icing.

What is the rate-of-change controller?

It prevents the UDP from increasing too rapidly by controlling the rate of pressure increase from the turbocharger.

What is the pressure ratio controller?

It prevents the turbocharger from boosting the UDP more than 2.2 times ambient pressure.

The purpose of an air scoop at the intake of the induction system is to:

It supply air to the induction system while increasing the incoming air pressure and bring sufficient quantity of air.

Where would an inlet air heater be located in the induction system of a fuel injected engine?

It would be located behind that air filter before the fuel injected unit so that the warm air can enter the induction system to thaw the ice.

What is critical altitude?

It's the max altitude that at which a turbocharger reciprocating engine can deliver its rated horsepower.

Which items cannot be used on exhaust components? Choose all that apply.

Lead, graphite, grease pencil and galvanized tools

Which manufacturer usually produces sea-level boosted engines?

Lycoming

How is a wastegate operated?

Manually or automatic

How are normally aspirated engines different than boosted engines?

Normally aspirated engine use only atmospheric air and does not boost the manifold pressure. A boosted in engine uses either an engine driver or exhaust driven compressor to maintain atmospheric pressure.

When starting an engine equipped with carburetor heat, in what position should the heater be placed?

On the startup of the engine the carburetor heat should be in the cold or the off position.

What happens when a plane reaches its critical altitude?

Once the aircraft reaches the critical altitude the horsepower and the manifold pressure decreases in proportion to the altitude increases by.

What is not an additional use of a turbocharger?

Reference pressure for the manifold pressure gauge.

What is the purpose of the Differential Pressure Controller?

Regulates turbocharger output at all throttle settings less than full power.

What is Upper Deck Pressure?

The air pressure between the outlet of the compressor and the throttle valve.

On an aircraft equipped with an alternate air system, what will happen if the main air scoop/duct or the air filter becomes clogged?

The alternate air door will open and unfiltered air will flow into the engine.

Explain how augmenter tubes work.

The augmenter works by aiding in cooling, increasing airflow through the engine cowling, and helping control the airflow.

Explain what critical altitude is and what the turbocharger does up to this point?

The critical altitude is the density of the altitude that the engine can maintain at a rated sea-level horsepower. The turbocharger uses max power until it reaches the critical altitude then it will decrease in power.

What is critical altitude?

The density altitude at which an engine can maintain it's rated sea level horsepower.

What is the purpose of the density controller in a sea level boosted turbocharger system?

The density controller regulates the bleed oil flow from the exhaust bypass valve assembly only during a full throttle operation.

What type of icing is a carburetor susceptible to. What causes each type, and how are the problems corrected?

The fuel evaporation ice is also known as the carburetor ice. There are three types of icing Impact ice, Throttle ice, and Fuel evaporation ice. The impact ice is caused by flying through freezing rain. Throttle ice is caused by pressure and the temperature drop as air flows across the throttle plate. Fuel evaporation ice is caused by fuel in the venturi. They are all problem corrected by the carburetor heat systems.

You are running up an engine on a cold day and the engine is struggling to make power. The plane was flown the previous day with no problems at all. What is the most likely cause of the engine running rough?

The most likely reason cause for the engine to be running rough is that it is experiencing fuel evaporation ice by the fuel evaporating in the venturi.

When and on what type of aircraft were short stack exhaust systems common? Why?

The short stack exhaust system is more on low-powered engines that do not have turbochargers, the reason that the short stack systems are on the low-power engines is to give them more power.

What are the 3 types of air filters? Give several advantages and disadvantages for each.

The three types of air filters are Flock, Paper cartridge, and Polyurethane. Flock Can be cleaned and reused but they are also expensive. The paper cartridges can sometimes be cleaned but most of the time they need to be replaced. Polyurethane is the cheapest to buy but you can't clean it has to be removed and replaced.

What component directly regulates the speed of the turbocharger?

The wastegate valve.

How does the wastegate work and what does it do for the turbocharger?

The wastegate works by opening or closing a valve if the valve is open all the exhaust gases will bypass the turbine going out the exhaust pipe. If the valve is closed all the exhaust gas flows to the turbine making it spine by the pressure being pursued by the exhaust gases.

In a manually controlled wastegate, the valve is connected by a linkage to which component?

Throttle

Which type if ice is caused by a temperature drop as air flows across the throttle plate?

Throttle ice

What is the purpose of a turbocharger system for a reciprocating aircraft engine?

To maintain a rate of sea level horsepower up to the critical altitude.

Critical altitude is the density altitude at which an engine can maintain its rated sea level horsepower.

True

Power decreases proportionally to altitude in a sea-level supercharged engine.

True

Short stack exhaust systems can be used on supercharged engines, however it is not common on modern aircraft.

True

The purpose of the exhaust system is to remove spent gasses of combustion and safely route them overboard.

True

The waste gate regulates the speed of the turbocharger.

True

Exhaust gas is used to turn the ___________.

Turbine wheel

What is the difference between a turbocharger and a turbo-supercharger?

Turbocharger is an exhaust drive and Turbo-supercharger is exhaust driven that is above the atmospheric pressure.

Air pressure after the compressor wheel is called what?

UDP

The Density Controller senses what?

UDP

What is the primary disadvantage of a supercharger?

Uses a large amount of engine power to suck out of the engine itself to simply produce power which is less efficient. It increases the temp in the engine which could result in a detonation.

How do fuel pressure gauges work?

Uses the pressure from the turbocharger to the upper deck pressure.

What is the most commonly used method for preventing carburetor icing?

Using carburetor heat which takes hot air from a heat exchanger which is around the exhaust muffler.

What is another name for the exhaust bypass valve?

Wastegate

Carburetor icing is most severe at.

When the air temp is between 30 to 40degrees F.

Why is Carburetor heat not generally used during takeoff unless absolutely necessary?

With the increase in the air temp the air becomes less dense so the engine has a reduction in power.

Which component compares UDP to MAP?

differential pressure controller

The APC controls the amount of oil that ___________ the wastegate controller.

leaves