Aircraft Systems Final Exam

Indicated horsepower on today's aircraft engines may be as high as what percent of the indicated horsepower?

10% to 20%

The U.S Standard Atmosphere was established in what year to provide pressure and temperature values to calculate volumetric efficiency.

1958

On most light aircraft horizontally opposed engines, how is the engine pressure-cooled?

2 openings in the nose cowling, one on either side of the propeller spinner

A typical intake system will cause ___ to ____ Hg pressure at takeoff RPM and open throttle.

2" - 3"

How many tools does a pilot have at their disposal in which to control engine temperatures?

4

Today's aircraft are designed to be operated at what maximum range power setting?

40 - 50 % (best miles/gallons)

At what degree is the intake valve timed to close?

50 degrees to 75 degrees past bottom dead center on the compression stroke

Almost all newer boot installation systems fasten the deicer boots to the surface with what?

Adhesives

What is a quick way to damage most engines?

Allow the engine to cool rapidly

Pilot should keep in mind turbocharger functions as an ___________________, increasing outside pressure several times.

Amplifier

What oil is used to replace mineral oil after the piston rings have seated?

Ashless dispersant oil.

One end of the rocker arm is sometimes slotted for this item.

Ball bearing

Why is a single valve spring not used?

Because it would surge at certain speeds.

The turbocharger not only supplies the compressed air to the engine induction system, but also provides air for what?

Cabin pressurization

How can a pilot verify that the cylinder valve head temperature is working properly?

Check cylinder head temperature gauge for ambient temperature

What is the term used where the throttle is fully open in order to achieve the desired power setting?

Critical Altitude

What has been reached when the wastegate closes?

Critical altitude

What is the abbreviation for excess thrust horsepower?

ETHP

What is the purpose of the firing order in aircraft engines?

Eliminate vibration and balance

What keeps the bleed valve closed ?

Engine Oil Pressure

A P-lead continuity check consists of idling the engine and moving 1 mag switch to the off position then quickly on. T/F?

False

Frost adds appreciable weight. T/F?

False

Heat and work are not theoretically interchangeable. T/F?

False

In reducing friction, water is a great cusion between metal parts. T/F?

False

The baffles direct air over the exhaust system to keep it cool. T/F?

False

The effects of humidity on power will increase as temperature decreases. T/F?

False

Timing the ignition and the valve events will not vary in different engines. T/F?

False

Volumetric efficiency is very good for these engines, normally or naturally aspirated engines. T/F?

False

You are able to cut open a sodium filled valve to expose the content safely. T/F?

False

When converting altimeter settings to ambient pressure, what type of elevation is used?

Field elevations

What type of propeller shaft is used on low-powered or medium powered reciprocating/turbojet engines?

Flanged

On the intake stroke of a compression engine, choose which of the following are correct.

Intake valve open, exhaust valve closed

What regulates the amount of air that passes over and around the tubes of the intercooler?

Intercooler shutters

In Chapter 14 what type aircraft has a chemical rain repellent system that uses a liquid chemical sprayed on the windshield tp prevent water reaching the surface of the glass?

Jet transport

What is the most important part of deicer boot maintenance?

Keep the boots clean

The four-stroke engine has many advantages for use in aircraft. Pick one below that fits this statement.

Lends itself readily to high performance through supercharging.

Why is the tubular form of a push rod used in today's aircraft?

Lightness and strength

The pilot's selection of power from the engine is done mostly by changing ______ or ______.

MAP or RPM

What supplies oil under pressure to bearings throughout the engine?

Mechanical Pump

What type of oil is used in in engine after overhaul or when new to facilitate wear-in or seating of piston rings?

Mineral Oil

What is the process by which steel cylinder soaks up nitrogen from gas which forms iron nitrides on the exposed surface.

Nitriding

Ambient pressure decreases at the rate of _____ inches of HG per 1000 ft of altitude gained?

One

________________ can be a source of concern to the pilot or operator who selects a particular manifold setting only to find it has changed in a few seconds and must be reset.

Overshoot

What does cold temperature affect in the engine?

Poor vaporization in carb

If pressure is too hight just before the instant of ignition, what will occur?

Premature ignition

What is used to measure the usable power output of an engine on a test stand?

Prony brake

Tapered, spined and flanged identify what component?

Propeller shafts

What is the purpose of the cylinder?

Provide a combustion chamber where burning and expansion of gases take place.

What is the purpose of the cylinder fins?

Radiate heat from the cylinders walls and heads

IF proper cowl flap management is not done, what could happen?

Rapid cooling of the engine

Where is the accessory end located on an engine?

Rear

What is used to compensate for the fluctuation of oil viscosity because of temperature changes?

Relief valve

What revolves on ball bearings at the rear end of the pump and bearing casing and the roller bearings at the turbine end?

Rotor

What 2 ways do bearing surfaces move in relation to each other?

Sliding movement and for one surface to roll over the other.

This device limits the amount of air that can be taken from manifold to pressurize the cabin, thus insuring adequate induction air for the engine.

Sonic Venturi

What is the purpose of the screen strainer at the bottom of the sump?

Stain undesirable particles from the oil.

What two methods are used to provide the engine with higher manifold pressures?

Supercharging and turbocharging

What is the difference in propeller shaft numbers on tapered and flanged shafts?

Tapered shafts are identified by a taper number and flanged are identified by SAE numbers.

The basic operating principles of a reciprocating engine deals with what 3 items?

Temperature, Pressure, and Volume

What is key for all engines to stay in the best condition, in respect to the manufacturer's recommendation?

That engine manufacturer's recommendation be followed for maintenance and overhauls.

The inside of a cylinder is called what?

The bore

What is one thing that augmenter tubes eliminate?

The use of controllable cowl flaps

What determines the performance of the engine-propeller combination?

Thrust Horsepower

For an aircraft to remain in a level, unaccelerated flight, what actions must be done?

Thrust must be provided that is equal and opposite in direction to the aircraft drag.

What is the purpose of the flexible rubber hose in the oil tank?

To ensure oil pickup during inverted maneuvers

A thermocouple consists of three dissimilar metals. T/F?

True

All reciprocating engines require the same temperature control to produce good combustion in the engine cylinders. T/F?

True

As long as torque increase is proportional to RPM decrease, the horsepower delivered at the shaft will remain unchanged. T/F?

True

If the engine is not running, pressure in the MAP will be equal to to ambient pressure? (engine cooled)

True

Two oil rings may be placed in the same groove on a piston. T/F?

True

What is designed to aid in cooling the cylinder internally?

Valve overlap

What is used to control air in augmenters?

Vanes

Resistance of an oil to flow is known as_______

Viscosity

What condition will cause cylinders to have to be replaced?

When a specified number of inches of cooling fins are missing.

The "W" in 5W-30 means what?

Winter use in cold climates

What are the two types of ice control systems used on aircraft?

anti-icing and deicing

Turbochargers usually compress the fuel/air mixture from the carburetor when?

before it is mixed with metered fuel from carburetor

The windshield of transport category aircraft are heated not only to prevent ice, but to strengthen them against what?

bird strikes

There are two types of air pumps used to provide instrument airflow, both are ____________ pumps?

both are vane-typed

What is the valve mechanism of an opposed engine operated by?

camshaft

The downward action of the piston, acting on the crankshaft through the connecting rod, is converted to what type of motion by the crankshaft?

circular or rotary motion

What does today's modern automatic turbocharger system utilize to regulate the wastergate?

density controller and differential pressure controller

What is used to remove water that has passed through a moisture separator?

desiccant

What could you install to conserve engine warmth in cold weather operations?

engine blanket

The most common english system unit to measure work is?

foot-pound

The faster the air flows and the more twisted the path the air must travel, there will be ______loss which appears as a pressure loss.

friction

Humidity effects become _______________ at high altitudes.

inconsequential

Turbochargers are designed to deliver compressed air to the _____________ of the carburetor or fuel/air control unit of an engine.

inlet

Which type of engine is arranged so that the firing of cylinders are evenly distributed along the crankshaft?

inline engine

In order for the fuel/air mixture to get into the cylinders, it must pass through what?

intake manifold pipes and intake valve

What is the average absolute pressure of air or fuel/air charge in the intake manifold called? Hint -It is also measured in inches of mercury(Hg).

manifold pressure

What type of planetary gear reduction system is used with in-line type engines?

pinion and sour

Bearings are required to take what kind of loads?

radial and thrust load or a combo of both

What type of bearing is used on high-power aircraft engines' crankshafts?

straight roller bearings

If the ration of useful work being done by an engine based on the heat energy of the fuel it uses, it will be expressed in work or heat units. What term is it called by?

thermal efficiency

What is used in the oil cooler to control oil temperatures?

thermostat

Where is the number one cylinder located on a radial engine?

top

What term is more correctly applied to a engine system that is both a turbocharger that boosts air pressure before the carb and a supercharger that further boosts pressure of the fuel/air mixture?

turbo-supercharger

What controls the volume of exhaust gas directed into the turbine and thereby regulates the speed of the rotor and the output of the compressor impeller?

wastegate

A ________________ wing system is available for small aircraft as as a retrofit.

weeping