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Файл:Aircraft Maintenance. Учебное пособие
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UNIT 4. INSTRUMENTS
Lower Display
The lower display provides elapsed time (ET) from 00 hours 00 minutes to 99
hours 59 minutes or chronographic time (CHR) from 00 minutes 00 seconds to
99 minutes 59 seconds. Control of this displa y is provided by the ET and CHR
switches.
DATE Switch
The DATE is shown on the GMT display when the DATE push button is pushed.
SET Switch
The GMT or date display is controlled by th e SET switch. This switch is located
in the lower corner of the indicator. The normal position is RUN.
Clock Switch
The Captain’s and F/O’s CLOCK switches (= remote clock switches) are located
on either side of the glareshield. The CHR and remote clock switches are connected in parallel and operate the chronograph display. Both switches cycle the
chronograph through the start, hold and reset functions of the chronograph mode.
BITE
All clock failures are indicated in the same man ner. The clock displays go blank
and the sweep second hand is frozen. In addition, transmission of GMT output
data words is halted.
Elapsed Time Operation
The elapsed time (ET) control switch is located in the lower left corner. This
switch operates as follows:
61
AIRCRAFT MAINTENANCE
• In the RESET position, the ET display is blanked and the elapsed time in-
dication is set to zero. The RESET position is sprin g loaded to return the switch
to the HLD position.
• The HLD (hold) position of the switch freezes the ET display at the present
indicated value.
• In the RUN position, time is accumulated from the last hold or reset condi-
tion. The display automatically advances from this indicated value.
Chrono Time Operation
The CHR switch is located in the upper left co rner. This switch operates as follows:
• The first press of the switch starts the chronograph running.
• A second press of the switch freezes the chronograph display at the present
indicated value.
• A third press of the switch resets the CHR accumulator to zero. The contents
of the ET accumulator is then displayed. If the ET accumulator contains zero, the
elapsed time display is blanked and the sweep second hand goes to zero.
Chronograph operation replaces the display of the elapsed time, but does not affect the internal operation of the ET accumulator.
GMT Setting
The GMT is adjusted by the SET switch.
• The RUN setting of this switch is the normal o perating position for
the clock. GMT is shown continuously while in this mode.
• The HLD (hold) setting is used to freeze the GMT display. Setting
the switch to this position will hold the display at its present indicated value.
• The MS (minute slew) setting is used for slow slew operation. When
set to this position, the seconds display is reset to zero. The minute display automatically advances at a rate of 1 minute/second. The hours display is frozen at
its present indicated value.
• The HS (hour slew) setting is used for fast slew operation. When in
this position, the hours display automatically advances at a rate of 1 hour/second.
The minutes display is frozen at its present indicated value.
Date Setting
Setting the date can be accomplished by the combined use of the SET switch and
the push button DATE switch. The day control function on the SET swit ch pos itions are: D, M, and Y, which are located adjacent to HS, MS, and HLD of the
GMT control, respectively. Each function is operated as follows:
62
UNIT 4. INSTRUMENTS
1. push
a. data
2. second
b. button
3. elapsed
c. condition
4. glare
d. shield
5. date
e. switch
6. output
f. time
7. run
g. panel
8. reset
h. display
9. control
i. position
10. instrument
j. hand
1. upper
a. moving
2. present
b. lower
3. internal
c. distant
4. slow
d. past
5. combined
e. careless
6. adjacent
f. external
7. frozen
g. left
8. continuous
h. fast
9. accurate
i. interrupted
10. elapsed
j. separate
• The D setting is used for changing the day display. When in this p o-
sition, the day display automatically advances at a rate of one day per second up
to maximum value of 31,30, 29, or 28 depending on the month setting and reincrementing from 01. The month display does not change.
• The M setting is used for changing month display. When in this p o-
sition, the month display automatically advances at a rate of one month per second, up to maximum value of 12 and reincrementing from 01. The day display
does not change.
• The Y setting is used for changing year display. Turning the SET
switch to Y position will cause the two right hand digits to update one year per
second up to maximum value of 99 and reincrementing from 00. The two left
hand digits will be blank.
Exercise 1. Match the parts of the compounds and translate them.
Exercise 2. Match the antonyms.
63
AIRCRAFT MAINTENANCE
Exercise 3. Answer the questions.
1. How is the GMT output provided?
2. What I the time accuracy?
3. Where are the electronic clocks located?
4. What is the difference between the upper and lower displays?
5. How is the display controlled?
6. How are the failures indicated?
7. How does the elapsed time control operate?
8. How does the chrono time switch work ?
9. How does the GMT adjusted?
10. How can setting the date be accomplished?
BASIC SENTENCE STRUCTURE
Exercise 4. Use the examples in the notes to identify the subject, verb,
object, means or purpose in the five sentences below.
1. The forward mount comprises four attach bolts. (Subject, verb, object)
2. The, actuator assembly has two electrical DC motors. (SUBJECT ,
VERB , OBJECT)
3. The aircraft attitude is indicated by a sphere. (SUBJECT, VERB,
MEANS)
4. Do not touch the hot parts to prevent bums, (VERB, OBJECT,
REASON).
5. This S/B recommends the installation of shims to improve fatigue life. (SUB-
JECT, VERB, PURPOSE).
Exercise 5. Identify the part of the sentence, which is in bold type, as
in the examples:
_ push-buttons enable selection of the ALT ACQ modes.
“Two push-buttons” = the subject.
- The piping is attached by two clam ps in order to avoid vibration.
“In order to avoid vibration” = the purpose or reason.
1. Each ground spoiler is positioned under hydrau lic pre ssure.
2. Restrictors are installed to limit the terminal velocity.
3. The pitch control channel contains the computing circuitry for receiving data
from the aircraft sensors.
4. Additional extension actuates the valve.
5. Heat from a broken duct can damage airplane structure.
64
UNIT 4. INSTRUMENTS
Exercise 6. Identify the parts of the paragraph below, which are in
bold type.
Extension and retraction of the nose gear is controlled (1) by the selector valve,
and (2) occurs simultaneously with the operation of the main gear. (3) An actu-
ator is pressurized (4) to raise and to lower the nose gear. The actuator acts d irectly (5) on the nose gear trunnion. A small actuator operates (6) to lock and
to unlock the nose gear. A bypass valve linked to the nose gear lock mechanism
(7) prevents hydraulic pressure from reaching the nose gear actuator before the
gear unlocks. A cutout valve is inco rporated (8) to cut off the steering system
hydraulic pressure when the nose gear is retracted. (9) Nose gear doors are op-
erated mechanically by gear retraction and extension movements (10) through a
cable system.
1. .. ... 6.
2. 7.
3. 8.
4. ... . 9.
5. 10.
Exercise 7. The parts of these sentences are in the incorrect order.
Put them into the correct order as in the example:
is moved to the up po sition/to retract the gear, / the control handle
The control handle is moved to the up position to retract the gear. or
To retract the gear, the control handle is moved to the up position.
1. are connected/to the steering cables/the rudder pedals
2. 3000 psi hydraulic fluid/the metering valve/to the actuator/directs
3. is/the compressor section/the source of compressed air
4. entering the system/to prevent oil/seals/are installed
5. a signal/the sensor/ to turn on the red waming/provides
6. controls/to dampen yaw axis movement/the yaw damper system/the rudder
7. by two pumps/system pressure/is supplied
8. two pumps/system pressure/supply
9. the push-button/the system/resets/pushing
10. the valve/opens and closes/to control the fuel flow/an electrical motor
Exercise 8. Try to put these different parts of a sentence into the cor-
rect order as in the example.
transmit/to the monitoring unit/the two pressure transducers/the signals
The two pressure transducers transmit the signals to the monitoring unit.
65
AIRCRAFT MAINTENANCE
Don’t forget to check your answers with the Exercise Key.
1. the bleed air temperature/a precooler/conrrols
2. the autobrake system/pushmg LO, MED or MAX/arms
3. to the seat tracks/with two fasteners/the seat unit/an attachment fitting/attaches
4. of several transmitrers/inhibirs/an electronic device/the simultaneous selection
5. the 115 V-400 Hz current/the exciters/to enable ignition/into high voltage,
pulsating current/transform
6. to control the aircraft/ the main information/presents/the screen
7. from the engine HP compressor/by a heat exchange process/cools/the pre-
cooler/the hot air
8. to open the valve/necessary/a minimum upstream pressure of 8 psig/is
9. comprise/extending from frame 1 to frame 24/the lower section of the fuse-
lage/3 skin panels
10. with the screw the washer and the nut/the bolt/install 35
11. to drive the valve/if the other motor does not operateypermits/the gear
svstem/one motor
12. indicate/two green lines/that the protection is available/inside the speed scale
13. the air pressure an anti-ice valve/controls/at the required value
14. the position/two switc he s/a ccording to a logic/give
15. under spring pressure/the poppet valve/on to the valve seat/moves
Exercise 9. There is no punctuation in this paragraph. Read it and de-
cide where the sentences are. Add the punctuation and capital letters.
HYDRAULIC POWER TRANSFER UNIT
FIGURE 003
the filter bowl screws on to the flanged mounting it contains the filter ele-
ment and holds it against the mounting a seal prevents leakage the bowl is
screwed tight by means of a square tightening lug on the bottom surface the filter
element has a support tube with a spigot which opens the inner valve when the
filter ele¬ment is fitted filter power of the element is 15 microns 0.0006 in. the
red clog¬ging indicator is protected by a transparent cap which is integral with
the mount¬ing the indicator becomes visible when any filter clogging causes
pressure to drop to 6 bars 87 psi
Exercise 10. All the words in these 10 sentences are stuck together. De-
tach them, as in the example, in order to find the meaning of the sentences.
Thesurge-venttankisdesignedtoabsorbtheeffectoffuelsurges.
The surge-vent tank is designed to absorb the effect of fuel surges.
66
UNIT 4. INSTRUMENTS
1. Thegearcanextendbyfreefall.
2. Theoverheadracksaremountedontheceiling.
3. Thereisaniiuerfacebetweent hefi redetectionsystemandthemasterwarningcon
troHer.
4. Disconnecttheretumlinefromthecasedrainhose.
5. Anydropinvoltageisdetectedbythevokagemonitor.
6. TheATCtransponderiselectricallysuppliedbutnotoperating.
7. Checkthatthedoorsareflushwiththefuselageskin.
8. Theambermagneticindicatorshowsthevalveisin transit.
9. Thegroundspoilersarearm edbeforelanding.
10. Theaircraftsymbolisslavedtoacomputer.
Text B. RECORDERS
Vocabulary
assignment – задача
strapped –- фиксированный
mandatory – обязательный
beacon – радиомаяк
acquisition – получение
preconditioning – предварительная обработка
multiplexing – многоканальная передача
scaling – масштабное копирование
external – внешний
malfunction -– несрабатывание
excitation – питание
solid state memory – твердотельная память
survivable – малоуязвимый
hardened – упроченный
impact – удар
stainless steel – нержавеющая
сталь
dust cover – пылезащитная крышка
portable – переносной
immerse – погружать
tape deck – лентопротяжное устройство
erasing стирание
extract – извлекать
lateral – боковой
67
AIRCRAFT MAINTENANCE
longitudinal – продольный
acceleration – ускорение
self-contained – автономный
sealed – герметичный
Flight Data Recorder System FDRS/ Aircraft Conditioning
Monitoring System ACMS
Because they put together the function of DFDRS and ACMS in one box, the
unit is called DFDAMRU (Digital Flight Data and Management Recording
Unit). In the question of power supply, location and some handling we can’t divide this two systems, but generally they have two individually duties and use
therefore different associated systems:
• The DFDRS (Digital Flight Data Recording System) fulfil assignments for
the authority, by recording of important (mandatory) Parameters, which are
realized by the FDAU-part of the DFDAMRU and the following systems
- DFDR, Digital Flight Data Recorder
- ACC, three axis accelerometer
- Flight Recorder Test Module
- Event Push Button.
An ULB (Under Water Locator Beacon) is strapped to the DFDR.
• The ACMS (Aircraft Conditioning Monitoring System) fulfil assignments of
continuous control of essential Engine-Data for Engine Condition Monitoring
and other flight data and aircraft data, which is realized by the use of the
DMU-part (Data Management Unit) of the DFDAMRU and the following
systems:
- MCDU
- Printer
- Print Push Button
- ADL, Airborne Data Loader
- Diskettes.
Cockpit Location Of Dfdr/Acms
Sensors
The following Flight Control Sensors are only used for data recording:
• Control Wheel Position Sensor (M520)
• Control Column Position Sensor (M521)
• Rudder Pedal Position Sensor (M522)
• Horizontal Stabilizer Position Sensor (M1192)
68
UNIT 4. INSTRUMENTS
Spare Paper Rolls
Two spare paper rolls are stored in the cockpit.
Flight Data Acquisition Unit (Fdau)
FDAU processes and prepares all input signals for recording. Electronic circuit s
in the FDAU provide isolation, perform the functio ns of preconditioning, mult iplexing, scaling, synchronization, and converting input signals of various forms
to digital format and sending them to the flight data recorder and the QAR for
storage. A test set plug and a BITE indicator are located on the front panel of the
FDAU. The test set plug is provided to connect external test equipment. The
BITE indicator comes on when BITE circuitry wit hin the FDAU detect a malfunction. The FDAU provides 28 volt dc power for the accelerometer excitation.
Flight Data Recorder
The flight data recorder stores the output data for the last 25 hours of airplane
operation. Data is stored on the 1/4-inch wide magnetic tape. The tape and
transport are located in a 1/2 ATR crash-proo f container within the flight data
recorder. Some aircraft have Fairchild Recorders without a magnetic tape, but
with a solid state memory. The Fairchild SSFDR uses data compression to store
aircraft flight information. The data is compressed by the compression/store data
acquisition circuit card. The data is stored in the crash survivable store unit. The
crash survivable store unit is a hardened cubical where the memory chips are located. The SSFDR will store 25 hours of data. The tape transport assembly protects the recorded data against fire and impact. This protection includes an inner
aluminum cover, isothermal protection shield, an outer stainless steel cas ing and
an exterior stainless steel dust cover. This design enables the flight data recorder
to meet a test of 20,000 pounds of crush per axis, and provides impact protection
of 1000 g’s for 5 msec. When the equipment is subjected to high thermal environments the isothermal insulation maintains the inner chamber at a s afe tempe rature. The front panel of the flight data recorder has a test connector and an underwater locator beacon (ULB). The test connector lets you attach a portable
tester or a copy recorder to the flight data recorder. The ULB transmits an ultrasonic signal when it is under wat er. There are no electrical connections between
the ULB and the flight data recorder. A battery within the ULB supplies the ULB
with power.
Underwater Locator Beacon (Ulb)
The ULB is a battery operated unit that transmits pulses when immersed in water. The ULB has a detection range of 2,000 to 4,000 yards and an operating life
of approximately 30 days.
69
AIRCRAFT MAINTENANCE
1. detect
a. acceleration
2. store
b. malfunction
3. meet
c. cartridge
4. provide
d. data
5. maintain
e. erasing
6. transmit
f. test
7. apply
g. protection
8. prevent
h. signal
9. extract
i. power
10. measure
j. temperature
Quick Access Recorder (Qar)
The QAR is a 3/8 ATR container weighing 6.25 kg and is on the electrical
equipment shelf E2-1. The QAR records maintenance data from the FDAU
through an electrical connector on the rear of the unit when the AIDS power is
applied. The QAR consists of a removable tape cartridge, power supply, electronic con-trol circuits, and tape deck assembly with motor. The front panel contains three indicator lights: The red FLAG indicator illuminates to indicate
FAILURE DETECTED The green TRACK 1 indicator ill uminates while track 1
is in use The red TAPE LOW indicator illuminates at the beginn ing of track 12 .
The QAR records the data sequentially on twelve tracks. The tape speed of
1.19 cm/sec corresponds to a data rate of 768 bits per second (bps) for a total re cording time of 50 hours. A memory circuit provides positive memory of tape
direction and track number during power off periods. The tape drive stops automatically at the end of the last track to prevent erasing previously recorded data
by re-recording the same segment of tape. When a tape cartridge is extracted, the
track memory circuit is automatically reset to track 1. A front panel push button
is also provided for manual reset to track 1. The front panel access door must be
properly closed before the QAR will oper-ate. The tape cartridge contains 180m
of 1/2 inch wide 3M tape.
Accelerometer
The 3-axis accelerometer, M517, measures vertical, lateral and longitudinal acceleration and provides a separat e output signal with respect to ground for each.
Excitation for the accelerometer is 28v dc supplied by the FDAU. The accelerometer is a self-contained sealed unit mounted on the aft side of the forward
wall of the right wheel well at station 664.
Exercise 10. Match the parts of the collocations.
70
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