Powerplant missed acs codes

What are three types of flow-Indicating systems used for turbine engines? (AM.lll.D.K1)

Vane-type flow meters,

synchronous mass-type flow meters, and

electronic motorless mass flow meters.

What do mass flow systems measure? (AM.III.D.K1)

The mass of the flow. This is affected by the density of the fuel which is in turn affected by the fuel temperature.

In what units is an electronic motorless mass flow meter system calibrated? (AM.III.D.K1)

Pounds per hour of fuel flow.

What is indicated in a turbine engine if the fuel flow for all conditions is high? (AM.III.D.K1)

If there are other instrument abnormalities, there are possibly damaged turbine components.

Who is authorized to repair a fuel flow indicating system? (AM.III.D.K1)

The components can be repaired only by an FAA approved repair station certificated for the particular instruments.

Where can you find the electrical power requirements for a fuel flow indicating system? (AM.III.D.K1)

In the aircraft maintenance manual.

Where in the fuel system is the fuel flow transmitter located? (AM.III.D.K1)

Between the fuel control and the fuel nozzles.

What kind of indicating system is used to measure oil temperature in a small, single-engine, general aviation airplane? (AM.III.D.K2)

A sealed system in which a bulb, partially filled with a highly volatile liquid, is installed inside the oil strainer. The bulb is connected to a pressure gauge by a copper tube. The pressure of the gas above the liquid is proportional to the temperature of the oil that surrounds the bulb, and the pressure gauge is calibrated in terms of temperature.

What type of instrument system is used for measuring cylinder-head temperature and exhaust gas temperature? (AM.III.D.K2)

A thermocouple system.

What kind of electrical instrument system is used for measuring oil temperature? (AM.III.D.K2)

A ratiometer-type system.

What should a thermocouple cylinder-head temperature indicator read when the engine is cold? (AM.111.D.K2)

The same as the outside air temperature gauge.

What is critical in the installation of the thermocouple leads for a cylinder-head temperature indicator, the length of the leads or their resistance? (AM.III.D.K2)

The resistance is critical, it must have the resistance specified on the indicator. This is usually 2 or 8 ohms.

What should a ratiometer temperature indicator read when the electrical power is off? (AM.III.D.K2)

The pointer should be off scale on the low side.

How does a ratiometer-type oil temperature gauge measure the temperature of the oil? (AM.III.D.K2)

A ratiometer measures the resistance of the temperature bulb. The indicator is calibrated in degrees Fahrenheit or Celsius rather than in ohms.

What kind of tachometer is used on most small single-engine airplanes? (AM.III.D.K3)

A magnetic drag tachometer that is similar to an automobile speedometer.

What would likely cause the pointer of a magnetic drag tachometer to oscillate? (AM.III.D.K3)

Either a dry cable connecting the indicator to the engine, or a kink in the cable housing.

What kind of tachometer is used on most large multi-engine airplanes? (AM.III.D.K3)

A three-phase AC electric tachometer.

What is measured to indicate the engine RPM with a three-phase AC electric tachometer? (AM.III.D.K3)

The frequency of the AC the tachometer generator produces.

What is used as a fire extinguishing agent In some older aircraft? (AM.III.E.K4)

Carbon dioxide (CO2).

What fire extinguishing agent Is used in the high-rate discharge bottles Installed In a jet transport aircraft? (AM.III.E.K4)

Halon 1211 or 1301.

How Is a high-rate discharge bottle of fire extinguishing agent discharged? (AM.III.E.K4)

A powder charge is ignited and it blows a cutter through a frangible disc that seals the bottle.

What precaution must be taken when checking the electrical circuit for igniting the powder charge in the valve of a high-rate discharge bottle (AM.I11.E.K4)

The current used to check the integrity of the electric circuit must not be high enough to ignite the powder charge.

What color and marking identifies the fluid lines that carry the fire extinguishing agent in an aircraft? (AM.III.E.K4)

Brown tape with a series of diamonds on it.

What Is straight mineral Oil? (AM.ll1.G.K1)

It is the lubricating oil as obtained by fractional distillation of crude oil. It does not have any additives.

What is ashless dispersant (AD) oil? (AM.III.G.K1)

A mineral lubricating oil containing additives that disperse the contaminants throughout the oil so they will not clump and clog oil passages. There are no ash forming additives in AD oil.

What is synthetic oil? (AM.III.G.K1)

A lubricating oil that is made by chemically changing the nature of an oil base to give it the needed characteristics. Synthetic oil is the primary oil for turbine engines.

Is automotive oil suitable for use in aircraft engines? (AM.III.G.K1)

No, automotive and aviation oils are formulated for entirely different operating conditions.

What is meant by a multiviscosity oil? (AM.III.G.K1)

It is a lubricating oil with a viscosity index improver that increases the viscosity of the oil when it is hot and decreases the viscosity when it is cold.

Where can you find the grade of engine oil specified for a particular aircraft? (AM.III.G.K1)

In the airplane flight manual or the pilot's operating handbook for the aircraft.

What are six functions of the oil in an aircraft engine? (AM.III.G.K2)

a. Reduces friction.

b. Seals and cushions.

c. Removes heat.

d. Cleans inside the engine.

e. Protects against corrosion.

f. Performs hydraulic action.

What is the purpose of an air-oil separator, or deaerator, In a turbine engine oil tank? (AM.III.G.K2)

In normal operation, the oil picks up a quantity of air and it is swirled as it enters the deaerator. The swirling action releases the air from the oil, and the air is used to pressurize the oil tank.

How is oil pressure regulated in an aircraft engine? (AM.III.G.K2)

A pressure-relief valve senses the desired pressure and sends excess oil back into the engine sump.

What is the purpose of the restricted orifice in the line between the oil pressure gauge and the engine? (AM.III.G.K2)

The restricted fitting helps dampen any pulsations in the oil pressure caused by the pump.

What is a hot-tank lubrication system for a turbojet engine? (AM.III.G.K2)

A lubrication system in which the oil cooler is in the pressure subsystem and the scavenged oil is not cooled before it is returned to the tank.

What is a cold-tank lubrication system for a turbojet engine? (AM.III.G.K2)

A lubrication system in which the oil cooler is in the scavenge subsystem, and the scavenged oil is cooled before it is returned to the tank.

What kind of electric starting system Is used on many of the smaller turbine engines? (AM.III.H.K7)

A starter-generator.

Why are air-turbine starters superior to electric starters for large turbine engines? (AM.III.H.K7)

They are light weight for the torque they produce.

Where does an air-turbine starter get its air for starting the engines on a jet transport airplane? (AM.11I.H.K7)

From an APU, GPU, or from a running engine.

What prevents too high an air pressure from overspeeding an air-turbine starter? (AM.III.H.K7)

The air shutoff and regulating valve.

Where does an air-turbine starter get its lubricating oil? (AM.III.H.K7)

It has a self-contained lubrication system with the oil held in the starter housing.

What device in an air-turbine starter warns an aviation mechanic if there are any metal chips or particles In the oil? (AM.111.H.K?)

Magnetic chip detectors warn of any metal contamination in the oil.

What is the function of the capacitor in a magneto? (AM.III.H.K8)

The capacitor minimizes arcing at the breaker points, and it speeds up the collapse of the primary current as the breaker points open.

What happens in a magneto ignition system when the ignition switch Is placed in the Off position? (AM.111.H.KS)

The primary circuit is connected to ground.

What Is checked when a magneto is internally timed? (AM.111.H.KS)

Internally timing a magneto consists of adjusting the breaker points so they will open at the instant the rotating magnet is in its E-gap position, and the distributor rotor is in position to direct the high voltage to cylinder number one.

In what position should the Ignition switch be placed when using a timing light on the magnetos? (AM.111.H.KB)

In the Both position.

What is the E-gap in magneto timing? (AM.111.H.KB)

The E-gap angle is the position of the rotating magnet where the primary current flowing in the magneto coil is the greatest. The breaker points open when the rotating magnet is in its E-gap position.

What malfunction in the ignition system would cause an aircraft reciprocating engine to continue to run after the ignition switch is placed in the Off position? (AM.111.H.KS)

The ignition switch is not grounding the magneto primary circuit.

What Is the function of a float carburetor? (AM.III.I.K2)

The float carburetor's function is to measure airflow through the engine induction system and dispense the appropriate amount of gasoline into the airflow for all engine operating perimeters and conditions. It must also provide the fuel in a state that is as vaporized as possible by the time ignition occurs in the engine cylinders.

What two things are adjusted when setting the Idling conditions on a float carburetor? (AM.lll.1.K2)

a. Idling RPM by adjusting the throttle stop.

b. Idling mixture by adjusting idle needle valve.

What would likely cause a reciprocating engine equipped with a float carburetor to hesitate momentarily when the throttle is rapidly advanced from Idle to full power? (AM.III.I.K2)

A malfunctioning accelerator pump.

What are the basic principles of a hydromechanical fuel control? (AM.III.I.K6)

A pure hydromechanical fuel control has no electronic interface assisting in computing or metering the fuel flow. It also is generally driven by the gas generator gear train of the engine to sense engine speed. Other mechanical engine parameters that are sensed are compressor discharge pressure, burner pressure, exhaust temperature, and inlet air temperature and pressure. Once the computing section determines the correct amount of fuel flow, the metering section through cams and servo valves delivers the fuel to the engine fuel system.

Why does ice form In the throat of a float carburetor? (AM.III.J.K2)

When liquid fuel evaporates it absorbs enough heat from the air to cause moisture to condense out and freeze.

How does a leak appear In an engine exhaust system? (AM.III.L.K1)

It normally looks like a gray or black feather-shaped streak coming from a crack or from a location where components are not in perfect alignment.

How can you check a reciprocating engine exhaust system for leaks? (AM.III.L.K1)

Pressurize the exhaust system with the discharge from a vacuum cleaner and wipe a soap solution over all joints and suspect areas. A leak will cause bubbles to form.

How do the components in the exhaust system of a turbocharged engine allow for expansion and contraction due to heat, and at the same time prevent leakage? (AM.III.L.K1)

Bellows and ball joints prevent leakage while allowing contraction and expansion.

Should a turbocharged engine be started with the waste gate open or closed? (AM.III.L.K1)

Open, so as much exhaust as possible will bypass the turbine.

What is the primary function of a reciprocating engine exhaust system? (AM.III.L.K1)

Its main function is to dispose of the gases with complete safety to the airframe and the occupants of the aircraft. The exhaust system can perform many useful functions, but its first duty is to provide protection against the potentially destructive action of the exhaust gases.

What is a short stack exhaust system? (AM.III.L.K1)

The short stack exhaust system utilizes open exhaust tubes with no mufflers. The short stack system is generally used on non-supercharged engines and low-powered engines where the noise level is not too objectionable.

Why do some aircraft engines have a critical range of operation? (AM.III.M.K1)

The engine and propeller combination have a resonant frequency problem in which excessive vibration can occur in a certain range of RPM. The tachometer for an aircraft with this limitation is marked with a red arc. When it is necessary to pass through this range It must be done as quickly as practical.

Does centrifugal twisting moment on a propeller blade tend to move the blades toward high pitch or toward low pitch? (AM.III.M.K1)

Toward low pitch.

Do the counterweights on a propeller tend to move the blades toward high pitch or toward low pitch? {AM.III.M.K1)

Toward high pitch.

What Is the function of the accumulator used with some McCauley feathering propellers? (AM.III.M.K1)

The accumulator stores oil under pressure when the engine is operating normally. This oil is used to help the propeller blades move toward low pitch when the propeller is being unfeathered.

What is meant by the alpha range of operation of a turboprop propeller? (AM.III.M.K1)

This is the in-flight mode of operation from takeoff to landing.

Should an adjustable-pitch propeller be in high pitch or in low pitch for takeoff? (AM.III.M.K1)

In low pitch.

What can be done to prevent the front cone from bottoming when installing a propeller on a splined shaft? (AM.III.M.K1)

Install a spacer behind the rear cone to move the propeller forward on the shaft.

Why is a propeller indexed to the engine crankshaft? (AM.III.M.K1)

The relationship between the propeller and the engine crankshaft is chosen to produce the minimum vibration.

How are propellers on a twin-engine airplane synchronized? (AM.III.M.K9)

The propeller governor of the master engine is set to the desired RPM. A signal from the master engine governor is sent to the control box which sends a signal to a stepping motor. This motor adjusts the propeller governor and fuel control of the slave engine causing it to maintain exactly the same RPM as the master engine.

How Is ice prevented from forming on propeller blades? (AM.III.M.K10)

A chemical anti-icing system is used. A mixture of isopropyl alcohol and ethylene glycol is pumped into a slinger ring on the back of the propeller hub. From there centrifugal force slings it out along the blades. Ice cannot form on the resulting slick surface.

How is ice removed from propeller blades? (AM.1I1.M.K10)

An electrothermal deicing system is used. Electrical heating elements are embedded in rubber boots that are bonded to the leading edges of the blades. Low-voltage DC flows from the propeller deicer control through brushes and slip rings to the heating elements. The timer sends current to one propeller for about 90 seconds and then to the other for the next 90 seconds. This allows the ice to form and then break loose and blow away.

How can you determine that the electrically heated deicer boots on the propeller blades are working as they should? (AM.III.M.K10)

Observe the loadmeter or ammeter to see if the proper current is flowing, and follow the sequence of boot heating by feeling with your hands to see which one is heating. The boots should all have a similar heat rise in the same length of time.

What does the pilot do to change the RPM of an engine equipped with a constant-speed propeller when it is operating within the constant-speed range? (AM.III.M.K4)

The pilot moves the propeller pitch control. This changes the compression on the speeder spring inside the governor which moves the pilot valve. The pilot valve directs oil into or out of the propeller to change the pitch of the blades. The change in pitch changes the air load on the propeller which changes the RPM.

What is the difference between a controllable propeller and a constant-speed propeller? (AM.III.M.K4)

Basically, it is the control system. A controllable-pitch propeller uses a manually operated oil valve to control the pitch, and a constant-speed propeller uses a governor to control the valve.

When making a magneto check on an engine equipped with a constant-speed propeller, should the propeller control be In the low-pitch or the high-pitch position? (AM.III.M.K4)

It should be in the low-pitch, high RPM position.