What will be the result of increasing the compression ratio?

Thermal efficiency will increase.

Swept volume and thermal efficiency will increase

With increase in altitude, exhaust back pressure will:

decrease and engine power output will improve

Increse and engine power output will decrease

decrease and engine power will decrease

In flight, pre-ignition in a piston engine may be reduced by:

richening the mixture and increasing RPM

weakening the mixture and increasing RPM

Engine driven fuel pumps on avgas engines are ?

Normally a vane pump and/or a gear pump.

Normally an accelerator pump and a gear pump.

Normally a vane pump and an accelerator pump.

What is the main difference in ignition initiation in a petrol and diesel engine?

In a diesel engine the mixture is ignited by spontaneous compression ignition.

In a MOGAS engine the mixture is ignited by spontaneous compression ignition.

The diesel is ignited by a spark plug.

The richness of a air/fuel mixture ratio is the ?

real mixture ratio relative to the theoretical ratio.

mass of fuel relative to the volume of air.

volume of fuel relative to the mass of the volume of air.

volume of fuel relative to the volume of air.

card2brain.ch

Using the altimeter in the cockpit how can we measure "pressure altitude"?

By selecting 1013hPa and reading off the altitude.

By selecting the airfield height and adjusting for temperature.

By selecting the airfield height and reading the air pressure adjuster.

By selecting 1013hPa and reading off the altitude.

By selecting the airfield height and adjusting for temperature.

By selecting the airfield height and reading the air pressure adjuster.

A rich mixture in terms of piston engine fuel system supply to the induction manifold is a mixture of air to fuel.

8:1

15:1

18:1

12:1

8:1

15:1

18:1

12:1

For maximum endurance the mixture control should be set to:

Weak

The chemically correct state

Rich

Weak

The chemically correct state

Rich

What is the best method for limiting the effects of vapour locking?

Operate the electrically driven fuel pump.

Close the cowl flaps to keep the engine hot.

Open the cowl flaps to keep the engine hot.

Operate the electrically driven fuel pump.

Close the cowl flaps to keep the engine hot.

Open the cowl flaps to keep the engine hot.

The purpose of the accelerator pump is?

Used to inject fuel into the main jet should the airflow increase rapidly.

Used to inject fuel into the main jet should the fuel flow increase rapidly.

Used to inject fuel into the main jet should the airflow increase rapidly.

Used to inject fuel into the main jet should the fuel flow increase rapidly.

In an aircraft equipped with a float type carburettor and a constant speed propeller, carburettor icing would probably first be detected by

A drop in manifold pressure.

A drop in manifold pressure and engine RPM.

A drop in engine RPM.

A drop in manifold pressure.

A drop in manifold pressure and engine RPM.

A drop in engine RPM.

How is a stable idle achieved in the carburettor?

By the use of a slow running duct.

By the correct use of the accelerator pump.

By the correct use of the priming pump.

By the use of a slow running duct.

By the correct use of the accelerator pump.

By the correct use of the priming pump.

The octane rating of a fuel characterises the :

anti-knock capability

fuel volatility

quantity of heat generated by its combustion

anti-knock capability

fuel volatility

quantity of heat generated by its combustion

For piston engines, mixture ratio is the ratio between the :

mass of fuel and mass of air entering the cylinder.

mass of fuel and volume of air entering the carburettor.

volume of fuel and volume of air entering the carburettor.

volume of fuel and volume of air entering the cylinder.

mass of fuel and mass of air entering the cylinder.

mass of fuel and volume of air entering the carburettor.

volume of fuel and volume of air entering the carburettor.

volume of fuel and volume of air entering the cylinder.

Which power settings are most likely to promote detonation in petrol engines?

High power weak mixture.

High power rich mixture.

Slow running or idle

High power weak mixture.

High power rich mixture.

Slow running or idle

Which statement is correct regarding fuel energy density?

Diesel fuel is higher (diesel = 147K BTU?s)-(avgas=132K BTU?s)

Avgas is higher (avgas = 147K BTU?s)-(diesel=132K BTU?s)

MOGAS is higher (mogas=149K BTU?s)-(diesel=147K BTU?s)

Diesel fuel is higher (diesel = 147K BTU?s)-(avgas=132K BTU?s)

Avgas is higher (avgas = 147K BTU?s)-(diesel=132K BTU?s)

MOGAS is higher (mogas=149K BTU?s)-(diesel=147K BTU?s)

What effect does the mixture fuel-air have on the flame front velocity

The cooler combustion flame front travels at a lower speed.

The hotter combustion flame front travels at a lower speed.

The cooler combustion flame front travels at a higher speed.

The cooler combustion flame front travels at a lower speed.

The hotter combustion flame front travels at a lower speed.

The cooler combustion flame front travels at a higher speed.

On a climb the decrease in pressure causes ....

boiling or vapour locks in lines which should be pressurised to overcome this

a decreasing fuel flow, leading to a decreased richness

a reduction in fuel flow requiring enrichment

the engine to over speed due to an increase in the fuel to air ratio

boiling or vapour locks in lines which should be pressurised to overcome this

a decreasing fuel flow, leading to a decreased richness

a reduction in fuel flow requiring enrichment

the engine to over speed due to an increase in the fuel to air ratio

When the carburettor air intake is in "Hot Air" the power output of the engine is reduced because:

the mixture is lighter

there is no filter on the hot air intake and foreign objects decrease combustion efficiency

the mixture is heavier

the mixture is lighter

there is no filter on the hot air intake and foreign objects decrease combustion efficiency

the mixture is heavier

What is the normal indication that a petrol engine is suffering from "Detonation"?

A distinctive knocking noise (pinking)

Blue smoke from the exhaust.

Black smoke from the exhaust.

A distinctive knocking noise (pinking)

Blue smoke from the exhaust.

Black smoke from the exhaust.

When would a pilot most likely expect carburettor icing?

On a cold wet day +5°C

On a cold wet day -8°C

On a cold dry day -20° C

On a cold wet day +5°C

On a cold wet day -8°C

On a cold dry day -20° C

Tetra ethyl lead is added to some aviation gasoline fuels to:

increase its resistance to detonation

Increase its calorific value

Increase its specific gravity

increase its resistance to detonation

Increase its calorific value

Increase its specific gravity

The colour of Aviation gasoline 100 LL is:

blue

green

yellow

blue

green

yellow

What is the purpose of the priming pump?

Inject fuel into the manifold prior to starting.

Inject fuel into the manifold after starting.

Inject fuel into the carburettor from the wing tank. (Low wing only)

Inject fuel into the manifold prior to starting.

Inject fuel into the manifold after starting.

Inject fuel into the carburettor from the wing tank. (Low wing only)

What is the purpose of power enrichment in a carburettor?

To cool the cylinder heads at high power and low power.

To cool the cylinder heads at high power only

To cool the cylinder heads at high power and low power.

To cool the cylinder heads at high power only

2 Groups of engines

Keyboard commands:

= turn,

= for-/backward,

= scroll

1. Piston engines 2. gas turbine engines systems

Piston engines 2 arten

Keyboard commands:

= turn,

= for-/backward,

= scroll

a) Unboosted/ Normal aspirated engine b)boosted

Unboosted/ Normal aspirated piston engine

Keyboard commands:

= turn,

= for-/backward,

= scroll

the ambient air is drawn into the cylinder by the piston

boosted piston engines

Keyboard commands:

= turn,

= for-/backward,

= scroll

a charger delivers compressed ambient air (more air mass) into the cylinder

Turboprop

Keyboard commands:

= turn,

= for-/backward,

= scroll

gas turbine driving a propeller to create the thrust force

Turbofan

Keyboard commands:

= turn,

= for-/backward,

= scroll

gas turbine driving a fan that creates thrust force as the reaction force to the acceleration of the air in the nozzle

Grundprinzip Piston engine

Keyboard commands:

= turn,

= for-/backward,

= scroll

The high pressure inside the cylinder during combustion creates a force on typ of the piston, which is transmitted to the crankshaft, creating torque.

Was kann bei inverted cylinders passierenN z.B. beim Sternenmotor

Keyboard commands:

= turn,

= for-/backward,

= scroll

Es entsteht ein Hydraulicing (oil flood) => Oil flows down into the cylinder head and blocks the movement of the piston. This oil must be drained (Säubern) from the cylinder by removing the spark plug before engine start

Welche Piston engines kommen am häufigsten in Airplanes vor?

Keyboard commands:

= turn,

= for-/backward,

= scroll

Horizontal opposed air-colled engines ==> Boxer => 4-6 cylinder

Sternenmotor

Keyboard commands:

= turn,

= for-/backward,

= scroll

Kurbelwellen in der Mitte => Ungerade Anzahl Zylinder ( bei 2-Reihiger Motor = gerade Zylinderanzahl) => Daraus ergibt sich die Zündreihenfolge

Verschiedene Arten Otto-Motoren

a) Reihenmotor b) V-Motor (Nockenwelle entscheidet, ob schneller oder langsamer Motor) c) Boxermotor (jeder Zylinder hat 2 Kerzen

vgl Bild

1) Zylinder 2) Kurbelwelle (Crankshaft) 3. Kurbelgehäuse (Crankcase) 4. Heat exchange

vgl. Bild

1. Vc (Clearance Volume) 2. TDC Top dead centre 3. bottom dead centre 23. Distance: length of stroke 4. Piston 5. Connecting Rod 6. connecting rod force 7. Crankshaft