AS-356 Section 1 Exam

Fuse

A circuit interrupting device consisting of a strip of wire that melts and breaks an electric circuit if the current exceeds a safe level. To restore service, the fuse must be replaced using a similar fuse with the same size and rating after correcting the cause of failure.

Generator

A device which converts mechanical energy into electrical energy.

Diode

A semiconductor device with two terminals, typically allowing the flow of current in one direction only. Diodes allow current to flow when the anode is positive in relation to the cathode.

A TRUSS type of airframe construction would have the following characteristics __________. A. made up of beams, struts, and bars to resist deformation. B. uses formers and frames to give shape to the fuselage. C. consists of frames, and formers along with additional longerons and stringers to add support.

A. made up of beams, struts, and bars to resist deformation.

SPARS run the __________ of the wing whereas RIBS run the __________ of the wing. A. span; chord line B. span; sweep C. leading edge; root

A. span; chord line

Cessna 172 structure

All metal semi-monocoque construction Front and rear carry-through spar Multi-spar because it has a front and rear spar 4 engine mount stringers Externally braces wing Integral fuel tank (wet tank) Vertical stabilizer

Hydraulic fuse

Automatically shuts off fluid flow if a line should break

A cantilevered wing _________. A. includes the use of wire braces and struts to support the wing. B. does not require any external supports. C. is a lighter wing because of its interna; design.

B. does not require any external supports.

"Bending" is __________. A. a combination of tension and shear. B. a combination of tension and torsion. C. a combination of tension and compression.

C. a combination of tension and compression.

"Strain" is __________. A. another word for "necking." B. the force applied to a material or structure. C. how much deformation has actually occurred.

C. how much deformation has actually occurred.

Diamond structure

CFRP semi-mono Wing Attached by bolts 2 spars per wing Top and bottom shell on each spar Fail-safe design Tail T-tail

A BATTERY converts __________ energy into __________ energy and a generator converts __________ energy into __________ energy. CHEMICAL; ELECTRICAL || MECHANICAL; ELECTRICAL ELECTRICAL; CHEMICAL || ELECTRICAL; MECHANICAL MECHANICAL; ELECTRICAL || CHEMICAL; ELECTRICAL

CHEMICAL; ELECTRICAL || MECHANICAL; ELECTRICAL

two types of powered pumps

CONSTANT DISPLACEMENT• VARIABLE DISPLACEMENT

Resistor function

CONTROL THE FLOW OF CURRENT2. PROTECT AGAINST VOLTAGE SPIKES3. PROVIDE THE PROPER VOLTAGE

Cacipator & Cacipetence

Capacitance — The ability of a body to store an electrical charge. Measured in farads as the ratio of the electric charge of the object (Q, measured in coulombs) to the voltage across the object (V, measured in volts). Capacitor — A device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator. Commonly used for filtering out voltage spikes.

In aviation, we expect to have a Closed Center hydraulic system because __________. Closed Center systems have a smoother response to flight control inputs, making it better for the passengers Closed Center systems have a quicker response to flight control inputs Closed Center systems cost less and are more reliable

Closed Center systems have a quicker response to flight control inputs

Pressure Relief Valve

DESIGNED TO OPEN AT A PRESET SYSTEM PRESSURE AND ROUTE FLUID BACK TO RESERVOIR• PREVENTS FAILURE OR RUPTURE OF OTHER HYDRAULIC COMPONENTS

In an OPEN CIRCUIT, the electrons __________, where as in a CLOSED CIRCUIT the electrons __________, ARE FREE; ARE NOT FREE FLOW; DO NOT FLOW DO NOT FLOW; FLOW

DO NOT FLOW; FLOW

two roles of an accumulator

Either a hydraulic savings account Or is there to absorb system pressure surges

Electron Flow Theory

Electricity flows from negative to positive terminals.

T or F: A linear actuator uses a rack and pinion to move the hydraulic arm back and forth.

False

Pascal's Law

Law stating that a change in pressure at any point in an enclosed fluid is transmitted equally throughout the fluid.

Open Center Hydraulic System

Less responsive, not used as much in aircraft Slower Not always under continuous pressure Pressure surges are less Smoother

two types of actuators

Linear actuator (one passed around in class) Rotary actuator (nose gear steering)

full ammeter left

MEANS BAD ALTERNATOR/GENERATOR

full ammeter right

MEANS BAD VOLTAGE REGULATOR

three wing spar designs

Monospar Multispar And box beam spar

Closed-center hydraulic system

More used in aircraft bc of instantaneous response Faster Always under continuous pressure Pressure surges are greater Not as smooth

two types of hydraulic reservoirs

Non pressurized Right-side up aircraft Fly in lower altitudes Pressurized Often found in airlines and MIL aircraft

NiCad Battery

Not pink Typical in turbo pwoered AC More expensive/meets higher deman d Requires bench testing Steady voltage until cliff Always keep it above 20%

fracture point

The point at which the material breaks

wing spar

This is the main support structure of the wing itself

Three ingredients of a battery

Three ingredients- metal #1, metal #2, and the electrolyte

Conventional flow theory

WRONG THEORY Starts at the positive and flows towards the negative.

Choosing Hydraulic fluid

Well suited to transmit and distribute force Different types to suit different requirement s System pressures Temperature (inside and outside) Corrosion Qualities that matter Viscosity Chemical stability Flash point Fire point

Cantilevered

a completely self-supporting wing on its own Fixed wing Mostly based on bending and torsion

COnvert DC to AC with

an inverter

Hydraulics in 172

brakes

hydraulics in da42

brakes prop landing gear

Brittle vs. Ductile

brittle- rock that break into smaller pieces as a result of stress (faults) ductile- type of solid-state flow that produces a change in shape of an object without fracturing (folds)

The selector valve- (circle shape)

changes the direction of the pressure

Shuttle valve- chooses which pressure we're going to furnish If one pump is putting out 2000 psi and the other 3000 psi which one would you choose

chooses which pressure we're going to furnish -If one pump is putting out 2000 psi and the other 3000 psi which one would you choose

Any system that has a __________ hydraulic pump must necessarily also have a pressure regulator. constant displacement variable displacement

constant displacement

Hydraulic Actuator

converts fluid energy into mechanical energy

rivet

distribute load

yield point

elastic limit of tissue plastic deformation begins

two types of resistors

fixed and variable (dimmer switch)

Priority valve-

gives priority to one component over the other -Do we need power to flight controls or reverse thrusters

Lead-Acid batteries __________ lose charge while NiCad batteries __________. rapidly; rapidly lose volts gradually; hold charge until they end with a rapid loss of charge hold charge until they end with a rapid loss of charge; gradually

gradually; hold charge until they end with a rapid loss of charge

two types of hydraulic pumps

hand pumps and power pumps

semi-cantilever wing

has struts like cessna

With respect to hydraulic reservoirs, those that are pressurized can typically be found in __________ and __________ aircraft. fixed-wing; rotary-wing high-altitude; tactical military tactical military; general aviation

high-altitude; tactical military

Hydraulic actuators convert __________ into __________. hydraulic fluid pressure; mechanical force mechanical force; hydraulic fluid pressure mechanical rotation; pneumatic pressure

hydraulic fluid pressure; mechanical force

Stress

is the amount of force we apply to a structure

Standby Hydraulic System

is there in case we loose one of the engine-driven pumps

When you see a check valve-

its a savings account accumaltor

check valve

makes sure fluid only goes in one direction only We don't want system pressure coming back

Shear

one layer sliding over the other

In a multi-spar aircraft, you're going to have behind the leading edge and

one ⅔ of the way back

plastic deformation

permanent change in shape by bending and folding

PDI Button

pressure differential indicator Gives indication of an impending bypass condition

The function of a standpipe in a hydraulic reservoir is to __________. reduce the amount of air bubbles due to cavitation of the fluid provide a reserve amount of hydraulic fluid to the emergency system in the event of a main system leak provide extra capacity for the expansion of hydraulic fluid

provide a reserve amount of hydraulic fluid to the emergency system in the event of a main system leak

The function of a PDI Button on a hydraulic filter is to __________. provide an indication of an impending hydraulic filter bypass condition provide an indication that it is time to change the filter based on hydraulic cycles provide an indication that hydraulic fluid is present and moving as per design intent

provide an indication of an impending hydraulic filter bypass condition

If you want to convert AC power to DC power you need a

rectifier

necking range

requires less stress to lead to complete deformation and then the fracture point

"Ultimate" system pressure refers to the pressure at which the system __________ while "Proof" system pressure refers to the pressure at which the system __________. must function even with deformation; ruptures ruptures; must function even with deformation finally qualifies for FAA certification; that was used to certify system reliability

ruptures; must function even with deformation

If I have a constant displacement pump and I'm putting the ____ amount of fluid through everytime the teeth come together

same

The purpose of a priority valve is to __________. give priority to the system chosen via the selector valve set up which hydraulic system gets fed fluid in the event that system pressure falls below a threshold setting isolate pressure away from the normal system in the event of a leak on the normal side

set up which hydraulic system gets fed fluid in the event that system pressure falls below a threshold setting

with a constant displacement pump takeoff power puts out more pressure vs. when at idle so you need

so you need a relief valve

Bending

splits upper surface into tension and bottom piece will be compression Reason why the very first planes were biplanes Combination of tension and compression

switches

stop start or change curent

every semi-monocoque design is a

stressed skin design

elastic deformation

substance deforms but if the stress is removed it will come back to the original shape

Stress-skin design

sue rivets to transmit to the load across the aircraft Allows you to lighten the aircraft

Catastrophic material area

the breaking point

ultimate strength

the maximum amount of stress a material can withstand without breaking

Hydraulics are still the "go to" technology for many aircraft because __________ the weight to power ratio is beneficial electrics are simply too expensive pneumatic systems are compressible

the weight to power ratio is beneficial

two types of aircraft structure

truss: has welded steel tubing longerons separated by diagonal members to endure the loads placed upon the aircraft monocoque: consists of a thin sheet aluminum alloy curved to fit the shell of the fuselage. stong and light

Contortion

twisting force Twist the ends of a beer can

Pressure switches/ indicators=

when the pressure drops below a preset value it sends a siginal to the standby hydraulic pump which turns it on powers the electrical motor and pressurizies the sytwm fro us

tension

when we try to pull something apart Example- pressurizing the cabin

Compression

when you're trying to crunch something together Crush a beer can against your head

factors affecting resistance

-Material -Length -Cross sectional area -Temperature

1 battery cycle consists of __________. a rotation of batteries in the electrical system the time that the BATT switch was turned from OFF to ON 1 discharge and 1 charge

1 discharge and 1 charge

generator voltage depends on

1. THE SPEED OF ARMATURE ROTATION 2. THE NUMBER OF WINDINGS ON THE ARMATURE 3. THE STRENGTH OF THE MAGNETIC FIELD

The ultimate limit load is

1.5x the design

flaps take 30 seconds to lower at

10 mp/hr

lead-acid battery

Pink Typical recip/ ga powered ac Most common/affordable Steadily decreasing voltage

loadmeter

REFLECTS THE TOTAL LOAD PLACED ON THE GENERATING CAPACITY OF THE ELECTRICAL SYSTEM

Hydraulic Sytem Components

Reservoir Pump Filter Selector valve Relief valve Actuator (bicycle pump with hydraulic fluid instead of air)

Flow-Control Valve

Route hydraulic system pressure Control the speed of fluid flow Allows various components to operate when desired

stressed skin

Skin absorbs the load and transfers it to the rivets to the rib (or the stringer) and then to the spar then to the fuselage

Two basic ways to load shed

Start removing equipment from the powered -Good way to go at night or in IMC -Consumes battery energy while you think Shut down everything and only add what you need -Good option if there's smoke or fire -Preserves battery but you loose SA

strain

Strain is the amount of deformation of that substance as a result of stress

constant speed drive

TAKE VARYING ENGINE ACCESSORY GEARBOX OUTPUT SPEEDS AND GIVES GEN A CONSTANT INPUT SPEED