203 terms

Jeppesen Airframe O & P 7. Airframe Electrical System, Jeppesen Airframe O & P 8. Hydraulic and Pneumatic Power Systems, Jeppesen Airframe O & P 9. Aircraft Landing Gear Systems, Jeppesen Airframe O & P 10. Position and Warning Systems, Jeppesen Airf...


Terms in this set (...)

What could cause an AC electric motor to run too fast?
Excessive applied voltage or shorted field windings.
What tool is used to check a motor or generator armature for shorts and opens under load conditions?
A Growler.
When using a Growler, what indication will occur when a short exists between an armature segment?
It vibrates and "chatters."
How is the output voltage of an alternator controlled?
By varying the field current that excites the alternator.
What instruments are used to monitor electrical system loads?
Ammeters and voltmeters.
How would you identify a specific wire in a wire bundle?
By the identification code marked on the wire.
What tool would you use to determine the size of an unmarked wire?
A wire gauge.
What color are the navigation lights on the wingtips?
The left wingtip is red, the right is green.
Name several types of electrical devices that would be considered intermittent loads on an electrical system.
Landing gear, cowl and wing flap motors, radio transmitters.
Why would it be necessary to analyze an electrical system before increasing the load on the system?
To determine that the generator capacity, wire size, and protective device capacity will not be exceeded.
What factors should be considered when determining the wire size for a particular application?
The system voltage, permissible voltage drop, current to be carried, wire length and whether the load is continuous or intermittent.
What is the relationship between the inside diameter of a conduit and the outside diameter of the wire bundle inside it?
The conduit must be 25% larger than the wire bundle.
What is the maximum number of terminal lugs that can be placed on a single terminal strip stud?
What is the proper length for a bonding jumper?
As short as practical, but long enough to allow free movement of the component.
Under what conditions must a switch be derated from its nominal rating?
When used with inductive circuits, circuits with high in-rush current, and with DC motors.
At what point do electric motors draw the most current?
When starting.
Circuit breakers are designed to open before what condition occurs?
Before the wire emits smoke.
At what point in a circuit should the protective device be located?
As close to the power source as possible.
What type of circuit breaker may not be used in an aircraft?
An automatic resetting type.
What part of an aircraft is identified by a white navigation light?
The tail.
What could cause an AC electric motor to run too slowly?
Lack of lubrication, defective wiring, or low applied voltage.
What should be done when making bonding or grounding connections between dissimilar materials?
Use a suitable washer so that any corrosion will occur on the washer.
Prior to making a continuity check, what must be done to an electrical circuit?
The power must be turned off.
What materials form the bases of the three types of hydraulic fluids?
Vegetable, mineral, and phosphate-esters.
What colors denote mineral-based and phosphate-ester-based hydraulic fluids?
Mineral based fluids are red and phosphate-ester based fluids are light purple.
What are the results of exposing lacquers, oil-based paint, plastic resins, and vinyl compounds to phosphate-ester based hydraulic fluid?
The materials will be damaged and/or softened, or the paint will peel.
Name several sources used to develop hydraulic pressure.
Hand pumps, engine-driven pumps, and electrically driven pumps.
What would cause the bypass valve in a hydraulic filter to open and allow unfiltered fluid to circulate in the system?
A clogged filter element.
Describe several methods of pressurizing a hydraulic reservoir.
Engine bleed air, system pressure acting on a small piston in the reservoir, using variable-displacement hydraulic pumps.
What feature prevents engine damage if an engine-driven hydraulic pump seizes or is overloaded?
A shear section in the pump driveshaft will break, disconnecting the pump from the engine.
Describe the purpose of a pressure relief valve.
Pressure relief valves limit the maximum pressure produced by the pump, thereby preventing failures of the system components.
Engine-driven pumps deliver the output fluid flow in what two forms?
As a constant volume and variable volume.
Describe the operation of a gear-type pump.
Two meshed gears, driven by a power source, rotate in a housing. Inlet fluid is carried around the outside of the gears and delivered to the outlet side as the gears rotate.
Describe the purpose of a pressure regulator.
Pressure regulators manage the output of the pump to maintain system pressure. They allow the pump to be unloaded so it turns without significant resistance.
What is the device that is used in some systems to supplement the pump output during periods of high demand?
An accumulator.
What are the three different types of accumulators?
Piston, diaphragm, and bladder.
What safety precautions must be taken prior to disassembling an accumulator?
Release all of the air or preload.
When a hydraulic unit is replaced, what precautions should be taken to avoid contamination of the system?
All lines should be capped or plugged immediately after they are disconnected.
What types of components or systems are pneumatically operated in some aircraft?
Landing gear, brakes, flaps, and other mechanical actuators.
Name several sources of pneumatic power.
Storage bottles, engine bleed air, engine-driven compressors or vane-type pumps.
What happens to excess pressure in a pneumatic system?
A relief valve vents it overboard.
What is the function of a restrictor in a pneumatic system?
To control the rate of flow of the airflow.
What are the reasons for periodically purging a pneumatic system?
To remove moisture and contaminants.
What is the purpose of a torque link on an oleo strut?
To keep the wheel in alignment and prevent the piston from coming out of the cylinder.
A landing gear shock strut should be inflated with what gas(es)?
Nitrogen or dry air.
What conditions should a mechanic look for during a regular inspection of the exposed piston section of a landing gear?
Cleanliness, evidence of damage, and proper extension.
What prevents air from leaking out between the two halves of a split wheel assembly?
The O-ring.
Why are fusible plugs installed on some aircraft wheels?
To release the pressure generated by eat build-up before a tire blows.
What safety precaution must be taken when removing a wheel from an axle or when disassembling a wheel?
Deflate the tire.
What are the visible signs of excessive heating on a wheel bearing?
The bearing surfaces show discoloration.
How are the pilot's nose wheel steering commands transmitted to the steering control unit of a large aircraft?
Steering signals may be transmitted mechanically, electrically, or hydraulically.
How is the nose wheel steering mechanism usually actuated on a small aircraft?
By means of a mechanical linkage connected to the rudder pedals.
What is the name of the unit that prevents a nose wheel from vibrating or oscillating?
A shimmy damper.
What are the most common sources of power used to extend and retract landing gear?
Hydraulic pressure and electric motors.
At what times should a gear retraction check be performed?
During annual or other inspections and following a hard landing.
What mechanism(s) ensures that a nose wheel is not turned as it retracts into its wheel-well?
Internal centering cams in the strut or an external track.
Name several types of brake actuating systems.
Independent master cylinders, boosted brakes, and power-controlled brakes.
What is the function of an anti-skid system?
Anti-skid systems allow large aircraft to achieve maximum braking effectiveness without allowing wheels to skid or lock.
What is the purpose of a debooster?
To reduce hydraulic system high pressure to a lower value for more satisfactory brake action.
Describe two methods of bleeding brakes.
A pressure pot can be attached to the bleeder valve and fluid forced back towards the master cylinder and/or reservoir, or the master cylinder can be used for forcing fluid from the reservoir to the brakes.
Before a brake system can be inspected for leaks, what action must be accomplished?
Pressure must be applied to the system.
What maintenance function has the greatest impact on tire service life?
Ensure that the tires are properly inflated.
What effect(s) does under-inflation have on aircraft tires?
Internal heat damage possibly leading to premature tire failure, and more tread wear on the shoulders than in the center.
What unit in an anti-skid system generates the anti-skid warning signal?
The control unit.
How is a pilot alerted that an anti-skid system has automatically returned to a manual brake system?
By a warning light.
What is the significance of an anti-skid warning?
The system is off or has failed.
By what usual means does the stall warning system in a small aircraft alert the pilot of an impending stall?
An audible alert and/or a warning light.
What devices are used to provide warnings fora retractable landing gear system?
A horn or other aural device, and a red warning light or indicator.
How can a pilot determine that the landing gear is down and locked?
A green light or lights and/or another type of visual indicator.
Name at least two conditions that would activate a takeoff configuration warning system in a jet transport aircraft.
Incorrect leading or training edge flap position, stabilizer position, or speed brake not stowed. The manufacturer may establish other conditions.
What landing gear position must be indicated by regulations?
Down and locked and up and locked.
Under what conditions will a landing gear aural warning sound?
When the throttle is retarded and the landing gear is not down and locked.
How does a takeoff configuration warning differ from a landing gear warning?
Takeoff warnings are usually an intermittent horns while landing gear warnings are steady.
What is the function o fa Mach airspeed warning system?
To alert the pilot that the never-exceed airspeed limit has been reached or exceeded.
What systems are commonly used to activate the landing gear warning systems?
The throttles (thrust levers) and the wing flaps.
Why do airplanes with bleed air anti-icing of the wing leading edge have an anti-ice over heat light(s)
To indicate an over-temperature condition, usually as the result of a break in the bleed air ducts.
What warning system may be required when a nickel-cadmium battery is installed in an aircraft?
A battery temperature monitoring system?
At what time would a check of a landing gear warning system normally be made?
During a landing gear retraction test.
What is the purpose of an annunciator system.
To show, by means of a warning light, that some system parameter requires attention by the flight crew.
If an aircraft with retractable landing gear has only one green light to indicate the gear is down and locked, how will the switches be connected, in series or in parallel?
In series.
Where would you locate the procedures for checking and adjusting the landing gear switches?
In the aircraft manufacture's manual.
What is the usual means for alerting the crew of a jet transport that the cabin doors are not properly closed?
A warning light.
Why are transport category aircraft equipped with a master caution and a warning system?
To alert the crew that a malfunction has occurred and corrective action may be required.
A static check may be performed on a manifold pressure gauge by using what piece of information?
Current atmospheric pressure.
What aircraft instrument can be used to check a manifold pressure gauge for proper indication?
The sensitive altimeter.
Name several of the indication errors that may be found in altimeters.
Scale errors, hysteresis, friction, installation.
What is the signal source in an electrical resistance-type temperature indicating system?
A temperature bulb or sensing element.
What type of temperature sensing system is normally used to measure turbine engine exhaust gas temperature?
A thermocouple-type system.
What operating parameter is indicated by a tachometer?
Engine RPM.
What is the name of the effect that causes a gyro to respond to an applied force at a point 90 degrees further in the direction of rotation?
Gyroscopic precession.
What are the three sources of power used to drive a gyroscopic turn indicator?
Air from a vacuum or pressure source, or an electric motor.
What are two items that should be considered during inspection of a magnetic compass?
The fluid must be clear, The housing must be full with no bubbles.
In what way do magnetic fields generated by electrical equipment and steel parts in the airplane affect a magnetic compass?
They deflect the compass from correct alignment with earth's magnetic field.
Describe the basic operating concept of a synchro-type remote indicating system.
A remote transmitter electrically signals a receiver inside the instrument.
What aircraft instruments are connected to the pitot-static system?
The altimeter, vertical speed indicator, airspeed indicator and mach meter in high-performance jets.
Why should you avoid cleaning obstructions from the sensing holes in a pitot-static system with a tool?
The holes are aerodynamically critical.
After components in a pitot-static system have been replaced, what tests or inspections are required?
The static system leak test specified by FAR 91.411.
What quantity is accurately measured by a capacitance-type fuel quantity indicating system?
The mass of the fuel.
Who is authorized to apply the range markings to an instrument dial face?
The manufacturer or a certified instrument repair station.
What is the purpose of a slippage mark on an instrument glass?
To indicate if the glass has moved.
What references should be consulted to determine the proper range markings for aircraft instruments?
The aircraft maintenance manual, aircraft flight manual, Type certificate data sheets or aircraft specifications.
What is the meaning of a yellow arc on the aircraft instrument?
A caution or limited flight operations range.
What is the reason for "swinging" a compass and how is it accomplished?
To compensate for deviations, by adjusting the compensating magnets.
What are the basic components of a radio communication system?
A microphone, transmitter, transmitting and receiving antennas, receiver and speaker or headphones.
what frequency range is used by most modern voice communications systems?
The VHF (Very high frequency) band.
What does the term "ADF" stand for?
Airborne Direction Finding.
What is the function of VOR equipment?
Name the components of a typical airborne VOR navigation system.
A receiver, antennas, frequency selector and a visual display indicator.
What does DME stand for?
Distance Measuring Equipment.
At what interval must an ATC transponder system be certified?
Every 24 calendar months.
Why are two antennas usually required for an ILS system?
The localizer and glideslope signals are transmitted on different frequencies.
What information does the glideslope beam provide?
Vertical guidance to enable the aircraft to maintain the correct descent angle.
What is the power source for an ELT (Emergency Locator Transmitter)?
An internal battery.
Describe one method on monitoring the signal output during and ELT test?
Tune a communications receiver to 121.5 MHz
How would you determine if the batteries in an ELT are due for recharge or replacement?
By looking for an expiration date for recharge or replacement on the battery and/or in the aircraft maintenance records.
At what time(s) is a test of an installed ELT permitted?
During the first 5 minutes after the hour and for no more than 3 sweeps.
Where on the aircraft would you expect to find a DME antenna?
Generally on the bottom of the fuselage in a location that isn't blocked by the wing during turns.
Describe the shape and location of a transponder antenna.
Either a short blade or short wire with a ball end located on the bottom of the fuselage.
Name the basic components of an autopilot system.
Gyros, servos, a controller, and an amplifier or computer.
What are the sensing elements of an autopilot system?
Attitude, directional, and turning gyros, and an altitude sensor.
What is the function of the servos in an autopilot system?
The servos actuate the flight controls.
What is the purpose of a bonding jumper from a radio shock mount to the airframe?
To provide a low-impedance ground return.
Describe the procedure used to route coaxial cable from an antenna to a receiver.
The cable should be supported every 2 feet, bends should be 10 times the cable diameter, and it should be routed separately from other wires.
What controls the temperature in a thermal anti-icing system?
Hot and cold air are mixed.
What are the sources of heat for thermal anti-icing systems.
Bleed air from the compressor section of a turbine engine, engine exhaust heat exchangers and combustion heaters.
What prevents overheating of the leading edges of a thermal anti-ice system operated by engine bleed air?
Overheat sensors signal the anti-icing valves to close and shot off the hot air.
What happens to the hot air used by a thermal anti-ice system after it has heated the surface?
The air is dumped overboard.
Why is it necessary to provide overheat protection for anti-icing systems that use turbine engine bleed air?
The air is hot enough to cause damage to the aircraft structure.
What are the effects of arcing on an electrically heated windshield?
Localized overheating and damage to the windshield.
Can the operation of an electrically heated pitot-tube be checked with the aircraft's ammeter, and if so how?
Yes, turn the pitot heater on and observe the deflection of the ammeter needle.
Describe several potential problems associated with electrically heated windshields.
Arcing, delamination, scratches, and discoloration.
Why do some pneumatic deicer boot systems have an electrically operated timer?
To automatically cycle the boots, provide the proper rest time, and then recycle the boots.
What are the two common methods of inflating pneumatic deicer boots?
Bleed air from a turbine engine or the exhaust from an engine-driven vacuum pump.
What procedure is used to hold deicer boots flat with the airfoil surface during flight?
Suction is applied to the boots.
Why do some deicer boots systems incorporate an oil separator?
If a wet pump system is used, the oil must be removed before it reaches the boots because oil damages the rubber.
What methods are used to attach a deicer boot to the leading edges of the wing and tail surfaces?
Adhesives, fairing strips and screws, or a combination of both.
What important step should be taken prior to making a cold-patch repair to a deicer boot?
Consult the manufacture's service manual an follow the repair instructions explicitly.
Describe the methods commonly used to remove rain from a windshield.
Windshield wipers, a blast of air, or chemical rain repellent.
What power sources are used to operate windshield wipers?
Electricity or hydraulic pressure.
Name two problems associated with in-flight operation of aircraft windshield wipers.
Insufficient blade pressure cause by aerodynamic forces and failure to oscillate fast enough.
Describe the operation of a pneumatic rain removal system.
A high velocity air blast prevents the rain from reaching the surface of the windshield.
What are the effects of spraying rain repellant on a dray windshield?
It smears and streaks, which reduces visibility, and it is hard to remove when dry.
Where would you find information on the acceptable limits of windshield delamination/
In reference material provided by the manufacture.
Is there any special requirement as to the type of oxygen used in an aircraft system, and if so what is it?
Only aviator's breathing oxygen should be used.
Describe the operating principle of a continuous-flow oxygen system.
High-pressure oxygen flows from the storage cylinder to a pressure regulator where its pressure is reduced and then to the mask outlets whenever the system is turned on.
Describe the operating principle of a pressure-demand oxygen system.
Demand systems allow oxygen to flow from the cylinder to the regulator and then to the mask only when the user inhales. Pressure-demand systems provide oxygen to the mask at higher than atmospheric pressure when used at extremely high altitudes, forcing oxygen into the user's lungs.
What should be used to purge an oxygen system of moisture?
Oxygen, dry air, or dry nitrogen.
What action must be taken when an oxygen system has been open to the atmosphere?
The system must be purged of any moisture.
Describe the safety precautions that should be observed when servicing oxygen systems.
Avoid all contact with petroleum-based oil or grease, don't smoke, keep everything very clean, service systems outdoors if at all possible, and keep the caps on the bottles to protect the valves.
What is a Roots blower?
A type of engine-driven compressor.
Name two different types of independent cabin air compressors.
Positive-displacement and centrifugal.
What is the source of pressurization air in most jet aircraft?
Engine bleed air.
What device provides the principal means of controlling cabin pressure?
The outflow valve.
What unitg regulates the position of an outflow valve?
The cabin pressure controller.
Name several methods used on reciprocating-engine aircraft for providing heated cabin air.
Exhaust should heat exchangers, combustion heaters, and electric heaters.
What is the function of the ventilating air in a combustion heater?
Ventilation air transports the heat from the heater into the cabin and prevents combustion gases from entering the cabin if the combustion chamber develops a crack.
What are the sources of ventilating air in a combustion heater?
Ram air in flight, a blower on the ground, or possibly a compressor if the airplane is pressurized.
Name the basic components of an air-cycle cooling system.
The compressor and expansion turbine, heat exchangers, and various valves.
Describe the basic operating principles that allow an air-cycle system to produce cool air.
Hot engine bleed air is cooled in the primary heat exchanger, compressed then cooled again in the secondary heat exchanger. The air is expanded across the turbine where energy is extracted and the pressure is reduced. This produced a large temperature drop.
Describe the basic operating principles of a water separator.
Cool, moist air is swirled so that water droplets are separated by centrifugal force, captured by a sock, and drained.
Name the principal components of a vapor-cycle system.
A compressor, condenser, expansion valve, and an evaporator.
In what significant way is a vapor-cycle cooling system different from an air-cycle system?
Vapor-cycle systems use a refrigerant liquid, usually freon.
Why is oil added to the refrigerant in a vapor-cycle air conditioning system?
To lubricate the compressor.
Why do some aircraft have fuel jettison systems?
To allow the crew to reduce the weight of the aircraft down to or below the maximum allowable landing weight.
Is there any reason why a fuel jettison system might be required on a small aircraft?
Yes, if the maximum takeoff weight exceeds the maximum allowable landing weight, a jettison system would be required.
What are some other names for a single-point fueling system?
An underwing or pressure fueling system.
Why do multi-engine airplanes have fuel crossfeed systems?
To allow any engine to draw fuel from any tank.
The fuel selector valve for a multi=engine aircraft must have at least three positions. What are they/
On, Off, and Crossfeed.
Why do some fuel tanks have internal baffles?
To resist fuel surging or sloshing caused by changes in the attitude of the aircraft.
What are the two types of fuel cells?
Integral or wet wing fuel cells, and bladder-type fuel cells.
What does the term "wet wing" mean?
It means that sealed portions of the aircraft wing structure form the fuel tank(s).
How is the weight of the fuel supported when bladder-type fuel cells are used?
The bladder is supported by the aircraft structure which contains it.
Why do turbine-engine aircraft have fuel temperature indicating systems?
To allow the crew to determine if the fuel is cold enough to produce a danger of the formation of ice crystals.
Name four types of fuel quantity gauging systems currently in use.
Sight gauges, mechanical, electric, and electronic gauges.
Why are electronic (capacitance-type) fuel quantity indicating systems more accurate than other types?
They measure the mass of the fuel instead of the volume.
What are drip gauges and sight gauges?
Underwing, bayonet-type fuel gauges.
What is the purpose of an in-transit light associated with an electrically operated fuel tank shutoff valve.
To provide an indication that the valve is in motion between one position and another.
For what reason is a fuel jettison system usually divided into two separate, independent systems, one for each wing?
To help maintain lateral stability by jettisoning fuel from a heavy wing if necessary.
What procedures should be followed regarding gaskets and seals when replacing fuel system components?
All old gaskets and seals should be replaced with new ones.
Is it possible for a fuel system to develop a leak that has no visible evidence such as a stain or spot, and if so, how?
An internal component such as a valve could develop a leak.
How is a fuel tank checked for leaks following a patch or welded repair?
The tank is slightly pressurized with air and the repaired area is leak-checked with a soap and water solution.
Name some advantages of a single-point fueling system.
It reduces fueling time, reduces chances for contamination and fire, and eliminates damage to the aircraft skin.
Why should you wait a period of time after fueling an aircraft before checking the fuel sumps?
To allow time for water and contaminates to settle at the drain point.
Briefly describe the components of a thermal switch fire detection system.
Temperature sensitive switches that complete a circuit at a specific temperature and trigger a warning.
Are thermal switches wired in series or in parallel with each other?
How are the detector units in a double-loop Fenwal system wired?
In parallel between two complete loops of wiring.
In what way is a thermocouple fire warning system different from a thermal switch system/
Thermocouple systems are sensitive to the rate of temperature change, whereas thermal switch systems respond to a specific temperature value.
Briefly describe the components of a Kidde continuous loop fire detection system.
A Kidde system has an Inconel tube containing one or more wires embedded in a ceramic core whose resistance changes with temperature.
Briefly describe the components and operation of a Lindberg fire detection system.
A stainless steel tube contains an inert gas and a discrete material that absorbs some of the gas.When the tube heats up, some gas is released, raising the pressure in the tube, which activates a pressure switch.
Describe the process or mechanism by which a photoelectric smoke detector generates a warning of possible fire.
Smoke particles refract light in the detector unit causing the photoelectric cell to conduct electricity and trigger the alarm.
How can the operation of a photoelectric smoke detector be tested?
By actuating a test switch.
Name two types of smoke detection systems used in aircraft.
Light refraction types and ionization types.
What are the usual locations where a carbon monoxide detector would be installed?
In the aircraft cockpit or cabin.
How does a carbon monoxide detector indicate the presence of this deadly gas?
The tan spot on the detector turns gray or black.
What are the possible effects of kinks and sharp bends in the sensing element(s) of a fire warning system?
False fire warnings caused by short circuits.
How is a Freon container checked for proper pressure?
A chart must be used to determine the maximum and minimum gauge pressure readings based on the ambient temperature.
Name the two basic types of fire extinguishing systems.
The conventional system and the high-rate discharge system.
Name the extinguishing agent most commonly used by conventional fire extinguishing systems.
Carbon dioxide (CO2).
Name the extinguishing agent most commonly used by high-rate discharge fire extinguishing systems.
How ar Freon bottles protected from excessively high temperatures and how can you tell that this has occurred?
A thermal fuse will release the agent if the bottle temperature exceeds a certain limit. This blows out a red indicator disc.
What condition is indicated if the yellow disk is missing in a fire extinguishing system?
The system has been discharged normally.
Describe the mechanism by which a Freon bottle is discharged.
An electrical signal fires an explosive squib, which ruptures a frangible disk.
How is the service life of a discharged cartridge calculated?
From the date stamped on the cartridge by the manufacturer.