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178 Cards in this Set
- Front
- Back
What are the 3 generators that make u a brushless AC generator?
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AC Exciter Generator Main AC Generator |
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What are the 2 main components of an AC generator? |
Rotor Assembly and the stator |
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What 3 components make up the stator? |
Exciter field Main Armature Windings |
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What are the 2 functions of the CSD governor system?
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Equalize the load between generators operating in parallel |
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If CSD output rotation drives the generator below 365 Hz, what component causes the generator t be removed from the bus?
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Underspeed Switch (USS) |
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If the CSD temperature rises to an overheat condition, what should be done to prevent further damage?
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The drive should be disconnected |
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What are the 7 types of protection provided by circuitry inside the GCU? |
Reactive Biasing Individual Phase sensing current sensing voltage regulator paralleling underfrequency |
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What 3 types of "protection" circuits are used only during parallel operation?
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Paralleling circuitry Under frequency protection |
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When No. 1 GCS is in the TEST position, there re voltmeter readings on both sides of the GCS and an ohmmeter of infinity through the generator exciter field. Why would the system voltmeter and frequency indicate zero?
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Open generator exciter field |
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Before 2 generators can be paralleled, the comparative potential of the generators and tie bus must be within what tolerances?
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Phase Angle less than 90 degrees |
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When the hydraulic solenoid valve is energized, what is the status of the emergency generator?
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Off |
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What happens when the emergency generator test switch is placed to the TEST position?
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Allows the emergency generator to operate while test is pushed |
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What power source energizes the EPDR?
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C-Phase of the emergency AC generator |
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What power source energizes the PFR?
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3 phase from main AC gen and/or an external power source |
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Which buses are powered by the emergency generator?
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Essential |
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During an aircraft sortie, the emergency generator was put on-line because of a main generator system malfunction. When the aircraft landed, the emergency generator dropped off-line. What is the probable malfunction?
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the EPIR |
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What component of the external power system provides a means of connecting external AC power to the aircraft systems?
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External Power Receptacle |
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What does the BPP provide?
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Protective and control functions during the utilization of external power |
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What does the BPP provide?
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Protective and control functions during the utilization of external power |
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What external power BPP component will prevent power from being applied to the power selector switch when voltage is less than 103 3+-
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UVR |
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When an overvoltage condition exists, what is the external power system time delay?
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it is inversely proportional to the amount of voltage exceeding 130 AC |
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When the external power unit is supplying correct power and that power can be applied to the aircraft, what indication is visible?
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Ready Light
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What APU component opens above 365 Hz to allow the USR to energize?
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USS |
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During which troubleshooting step do you review block diagrams?
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Understanding normal operation |
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Which steps do you coordinate with other maintenance specialties for an engine run?
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Performing repair and engine run |
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Now that you have limited the malfunction to specific components, what is the next step?
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Taking meter readings |
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What 3 internal components make up the TR?
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Step down transformer diode bank |
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For the internal cooling fan to operate, what must be provided to the TR? |
115 VAC input |
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What are the 2 functions of an RCR? |
Allow current flow only through one direction of current Prevent the TR units from connecting to the aircraft buses |
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Why is it beneficial to have a paralleled TR system?
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So that each TR will carry the same amount of load and provide a mean of supplying DC to the entire system if one fails. |
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What is the result of the 400-ampere current limiter is open?
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System would not parallel and one TR system wouldn't power entire system. |
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During a main DC power loss, what components prevent the batteries from powering buses other than the battery and emergency buses? |
RCR's |
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What voltage is required to energize the coil of the voltage relay inside an RCR? |
Above 22 VDC |
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What causes all internal relays inside an RCR to deenergize? |
Once the potential at the load is higher than the TR unit. |
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During which step do you perform a system operational check to determine if the RCRs are energizing if the normal battery is supplying DC to the battery bus and emergency DC bus is normal? |
Define the discrepancy |
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To determine whether the fault lies with the TR units or with the AC input when the battery is supplying DC to the battery bus and emergency DC bus in normal, you would want take your first meter readings where? |
At the input of the TR units. |
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If the normal battery will not charge but the standby battery is working and indicating properly, where would you look next?
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Normal batt relay indication circuit |
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What happens when the stabilizer is moving to 14 degrees below the horizontal plane?
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limit switches halt the power to the actuator drive unit |
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What are used to regulate the direction of the stabilizer trim screw?
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electrically controlled clutches |
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What is the purpose of the disconnect clutch in the stabilizer trim actuator assembly?
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to disconnect power actuators in the event that an actuator jams or binds |
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What position would the stabilizer trim cutout switch be in to deactivate the stabilizer trim safety relay?
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cutout |
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What could result if the pilot's and copilot's trim control switches are actuated in opposite directions?
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excessive wear of ball detent clutch or stalling of motor |
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How many minutes of actuator cooling time are necessary after you perform 2 minutes of operating time?
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13 minutes |
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What component tells the pilot when the ailerons are in the take-off position?
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take off trim indicator lights |
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What components are driven by the trim motor?
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ailerons |
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Will the control stick move after trim is initiated? |
No |
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Once you release the control trim switch, what will happen next?
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indicator lights extinguish |
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Before operating the take-off trim system, which 2 systems should be supplied with power?
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hydraulic |
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The first step in troubleshooting an aileron trim malfunction is what?
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do a warning lights test |
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How do wing flaps shorten landing and take-off roll?
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they increase lift effect |
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What are the 2 types of flaps used on heavy aircraft?
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fowler |
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What do slotted flaps eliminate?
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undesirable stall characteristics |
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Describe how the Fowler flaps are constructed?
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the lower surface rolls back on tracks |
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Why do fighter aircrafts use leading edge slats?
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to automatically reduce stall |
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Why do aircraft have speed brakes?
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to provide aerodynamic braking of the aircraft
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How are the speed brakes controlled?
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3 position speed brake switch, on the throttle grip |
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Why is the 43 degree position switch necessary?
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provides clearance of speed brakes and ground |
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During which step are you taking ohms checks to isolate the switch and wiring?
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voltage checks |
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From what source does the fuel-air starter get its supply of fuel? |
aircraft engine supply |
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At about what percent of engine speed will the fuel-air starter turn the engine? |
35% |
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When the engine reaches 35 percent rpm, what stops the starter? |
set of centrifugal switches |
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How is the fuel-air starter air bottle recharged?
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a compressor in the aircraft automatically recharges it |
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When does the heater in the air moisture separator operate? |
When the temp reaches 40 degrees F. prevents freezing |
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Whats the effect of an open centrifugal switch in the pneumatic starter system?
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Breaks ground circuit to the starter relay solenoid and turbine rotor quits rotating |
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What are the 2 sources of air that are supplied to the pneumatic starter? |
bled air from another engine in a multiengine aircraft |
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When high- pressure air is connected to the pressure side of a pneumatic starter and the regulating-and-shutoff valve is closed, where does the pressure go?
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through the filter, the pilot valve, and then gets vented overboard |
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Energizing what component allows pneumatic starter pressure to be vented to the top of the valve actuator? |
starter valve solenoid |
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What are the 2 purposes of the regulator valve in a pneumatic starter? |
Used to keep pressure on the turbine wheel and to maintain desired starter speed |
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What components make up the AC ignition system? |
ignition switch ignition transformer high ratio transformer inverter |
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About how many volts does the AC ignition deliver to the igniter plug? |
20,000 VAC |
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What are the 3 main components of a DC ignition system? |
transformer, igniter plug |
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What function does the vibrator unit in the DC ignition system perform?
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changes 28 VAC into pulsating current |
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What is the purpose of the C-135 engine ignition circuit?
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to ignite the fuel and air mixture in the engine |
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How many high-energy sparks are produced by the C-135 engine ignition circuit each second?
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2 per second |
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What can the high-energy sparks produced by the C-135 circuit do other than vaporize fuel?
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blasts carbon deposits away from the center electrode of the spark igniter
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What functions does the GTC provide?
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Used to start an engine or to drive an air turbine motor that drives a generator operates air conditioning |
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If the start and ignition hold relay is defective, could you start the GTC?
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No |
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What problem is indicated if the on-speed light does not come on when the GTC reaches 40,000 RPM and the light bulb is good? |
defective 95% speed switch |
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What is the first step in troubleshooting? |
know system operation |
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What is the final step in troubleshooting? |
operational check |
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What should you use to check the wiring between the ignition control unit and the igniter plug? |
Ohm meter. |
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What type of motor drives the boost pump in the fuel system? |
400 Hz 3 phase induction motor |
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What type of valve is generally used as a fire shutoff valve?
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Motor driven, sliding gate valves |
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Where are fire detectors normally placed on aircraft?
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conventional - engine and baggage department
jet - engine, nacelle, tail cone |
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What type of unit is a thermal switch? How does it operate? |
Warning system - 2 or more lights that are heat sensitive units. Circuit is completed when exposed to a specific temp. |
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How are the thermal switches connected? |
Fire - warning system = parallel connected in series with warning lights |
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How do the FENWAL and iron fireman detector switches operate? |
they are exposed to heat, all elements expand and this closes the contact |
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What are 2 precautions you must take when handling thermal switches? |
Never handle the shell with pliers Make sure shell is not damaged/distorted |
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Who can adjust the fire and overheat detector switches? |
Maintenance Personnel |
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What causes a thermocouple fire detector system to activate? |
Temperature rise |
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What 3 components are in the relay box of a thermocouple fire warning system? |
Sensitive relay, slave relay, and thermal test unit |
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How are the thermocouples connected in respect to each other? |
in series |
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How does the thermocouple operate in a warning system? |
large rise in temp produces a voltage. sends current to energize sensitive relay and closes slave relay |
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Why is it important that polarity check be made of a thermocouple that's in the fire and overheat warning system? |
Reverse polarity will fail to operate the system and will counteract other correct thermocouples |
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What is used to check the polarity of thermocouples? |
fire detection system tester |
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To what frequencies is the amplifier of a photoelectric fire detection system sensitive? |
between 7-60 Hz |
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How can you distinguish the fire warning light from the overheat light in the photoelectric fire detection system? |
fire warning lights burn steadily overheat warning flashes |
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How does sensing loop in a continuous loop fire warning system operate? |
rise in temperature reduces resistance between the inner and outer conductor. This unbalances the bridge circuit, sending voltage to the light |
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What component in the caution light circuit causes individual lights in the circuit to dim? |
Zener diode |
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Under normal conditions, at what potential is the emitter of Q1? |
Positive Biased |
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What are the 2 ways to turn off the master caution light? |
Removing the fault Pressing the MCL cover |
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What happens to transistor Q1 when its emitter-base junction becomes reverse biased? |
Cuts off Q1, which turns off MCL |
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What is the purpose of the take-off warning system? |
Monitor various systems in the aircraft and warn the pilot of improper positioning of flight controls. |
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What are 3 systems that the take off warning system monitors? |
Cargo doors Spoilers Thrust reversers |
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What components comprise the take off warning system? |
a set of relays that are actuated by various systems |
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On what 2 buses must power be applied for the take off warning system to be activated? |
Essential Navigation bus No. 2 and isolated AC bus |
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When troubleshooting a problem with the take off warning system, what action should you take after completing the operational check? |
replace bulbs |
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What should you remember when working with voltage? |
take extreme care be safe |
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To save yourself time, where should you start troubleshooting? |
halfway through the system |
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What is the final step of any troubleshooting and repair job? |
ops check |
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Which component has the responsibility to coordinate the flow of info on the data bus? |
Data Bus Controller |
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What are the RTs designed to do? |
transfer data between an aircraft system and the data bus controller |
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How many RTs can there be on any one data bus? |
32 max |
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What connects the RTs to the DBC? |
data buses |
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What are 4 of the advantages of a data bus system? |
Space and Wieght Reliability Performance Cost |
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With the aircraft in the proper configuration, what do you do to make the landing gear go to either the up or down position? |
Place the Landing Gear Control Handle in the gear-up position |
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What must occur before the actuating cylinder can extend the nose gear? |
up-lock cylinder releases the gear
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What 2 conditions must be satisfied before electrical power can be applied to the up solenoid on the landing gear selector valve? |
The aircraft must be in the air and the LGCH must be in the UP position |
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What conditions exist when the landing gear warning horn sounds? |
The landing gear is not down and locked when any throttle is placed below cruise power or the wings are extended 75% down |
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What circuit opens when the up-limit switches are actuated? What does the opened circuit do? |
Opens warning light circuit extinguishes warning light |
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Under what condition does the down-limit switch actuate? |
When landing gear is fully extended and locked |
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To what is a ground applied when the horn silence switch is pressed momentarily? |
the other side of the horn silence relay |
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What keeps the horn silent after the horn silence switch is pressed momentarily? |
a lock in circuit |
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What feature of the lock-in circuit permits the warning horn to sound off another time if a second throttle goes below cruise speed? |
it only maintains a lock in circuit for a particular throttle |
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To check out a faulty landing gear system, what 2 steps should be initiated prior to performing an operational check? |
place aircraft on jacks extend and retract landing gear |
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What is your next action if the position indicator coil reads infinity with an ohmmeter? |
replace position indicator |
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What does the Mark II antiskid system do? |
prevents prolonged skidding of any main landing gear wheel |
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What type of electrical device is a wheel speed transducer? |
AC generator |
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How is the frequency of the transducer governed? |
wheel speed |
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For what 2 reasons is the output signal from the wheel transducer formed into a square wave in the circuit card control channel? |
removes transient noise and prevents anti skid operation from stray signals |
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What circuit provides for a gradual application of brake pressure after a skid condition has terminated? |
Pressure bias modulation circuit |
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If the locked-wheel memory circuit is activated and any wheel stops rotating, what component will relieve brake pressure to that wheel? |
valve driver |
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How does the touchdown protection circuit prevent brake application when the gears are down and locked, but no weight is on the gears? |
applying 28 VDC to locked wheel circuit |
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What circuit monitors the output of the valve driver? |
indicator drive circuit |
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What circuit allows for a signal to simulate a locked or skidding wheel condition? |
test circuit |
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What circuit produces a nearly constant output, regardless of the variations in the airplane power supply? |
voltage regulator circuit |
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What function does the command potentiometer perform? |
steers the nose gear |
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What are the 4 types of circuits contained in the steering control box? |
steering direction sensing threshold detection solenoid drive fail safe |
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What component tells the system which way to turn once it receives inputs from the potentiometers? |
steering control box |
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How does the scissors assembly permit turning beyond the steering range? |
its attached at the apex with a quick disconnect |
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What type of switch is used for the NLG weight on wheel switch? |
roller actuated limit switch |
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once the aircraft is airborne, as the gear starts to retract and the NLG DOWN AND LOCK switch opens, what is deenergized? What happens to power from control box? |
NLG down lock relay power is removed |
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What switch will turn on the NWS system only if the NLG weight on wheels switch is closed? |
NWS A/R DISC MSL step switch |
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How does the NWS system remain energized after the NWS A/R DISC MSL step switch is released? |
K1 stays energized from holding circuit |
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If the pilot disengages the NWS system by depressing the NWS step switch and relay K1 remains energized, what would never happen? |
System would never disengage |
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What happens when the pilot needs to make a right turn and depresses the right rudder pedal forward? |
the wiper arm moves up the output voltage decreases |
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Where is the differential signal from the potentiometers routed? |
to the left and right error sensing circuits |
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What happens when the pilot needs to make a left turn and depresses the left rudder pedal forward? |
wiper arm goes down increases voltage to control box |
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In NWS system operation, when is hydraulic pressure sent to the steering actuator to turn the nose gear? |
once the left or right control valve energizes |
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What are the 4 components of the failure detection circuit? |
Error sensing circuit 120 ohm control module relays NWS malfunction relays fail safe circuit |
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What purpose does the steering control valve serve? |
directs 3000 psi of hydro pressure to NLG steering system |
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What component controls the NLG steering actuator? |
rudder pedal nose steering select valve |
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How is the rudder pedal nose-steering control relay energized? |
28 VDC from main DC bus No.2 |
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Why does a bomber or cargo aircraft require more lighting systems than a fighter? |
they are larger and have larger crews |
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How are instruments illuminated if the primary instrument lighting fails? |
Secondary lights |
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Why do console floodlights have red lenses? |
to reduce night blindness |
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Why are the white console floodlights connected to the DC bus system? |
used as emergency if AC fails |
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What does the pushbutton switch on the utility light do? |
provides full light intensity |
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What type of lights would you likely find on cargo aircraft that would not be on fighter aircraft? |
cargo cabin |
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What special use is sometimes made of wheel well lights on large aircraft? |
illuminates for refueling |
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How do the landing and taxi lights differ in overall purpose from the formation lights and position lights? |
they are used to illuminate other things, not used to draw attention |
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What feature in the nose gear landing light circuit in most aircraft prevents the landing light from being turned on accidentally? |
the landing gear needs to be down and locked before its turned on
|
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If an aircraft has a crosswind landing light, what type of front wheels is the light mounted on? |
steerable front wheels |
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How are the wing taxi lights of some tanker planes used for other than taxi operations? |
provides light for inflight refueling |
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What are the colors and locations of navigational wingtip lights? |
wingtips and tail left red, right green tail white |
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What opens and closes the flasher contacts to cause the taillight to flash on and off? |
DC motor that drives a rotary cam |
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Why are anti-collision lights designed to flash when they are used? |
to draw attention avoid collision |
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What component converts 28 VDC to 400 VDC to provide a trigger voltage for the strobe anti collision lights? |
step up transformer |
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What is the purpose of the lighting suppressors? |
prevents damage to lighting systems from power surges |
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Explain the function of the bulb filaments in the lights in the fuselage light system |
high wattage filament = bright light low wattage filament = dim light |
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How does a tanker aircraft produce a coded signal for aircraft attempting to rendezvous for air refueling? |
By controlling color and beam from rendezvous lights |
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The first step in troubleshooting a malfunction requires you to use what? |
T. O. |
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When zero voltage is found on the input terminal of the taxi light circuit relay, where do you usually check next? |
lamp terminals to ground |
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When checking a circuit with an ohmmeter, why must the section being checked be isolated from the rest of the circuit? |
So the only resistance being measured is from that segment |
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What type of switch is the locking cylinder unlock switch? |
Double pole, double throw microswitch |
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How many electrically controlled hydraulic valves are in the door system? |
5 |
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As soon as the ramp has reached the full closed position what happens next? |
left and right hand position switches activate to the up position |
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If the ramp failed to operate with the control switch set to open, whats the most probable malfunction? |
the circuit breaker or the ramp control valve |