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Файл:Aircraft Maintenance. Учебное пособие
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UNIT 1. AIR CONDITIONING. OXYGEN
1. air
a. louver
2. turbofan
b. manifold
3. ram
c. cycle
4. mixing
d. induce
5. distribution
e. discharge
6. exit
f. chamber
7. cooling
g. exchanger
8. compressor
h. air
9. heat
i. pack
10. cargo
j. compartment
Exercise 3. Match the halves of the compounds.
Exercise 4. Correct the statements.
1. The air conditioning system provides air to the engine.
2. The air conditioning packs control only the temperature.
3. There are four different flow schedules.
4. Two disk plates in an air mix valve work in opposite directions.
5. The ram air system employs outside air as a heating medium across the heat
exchanger.
6. The amount of opening is automatically con trolled to maintain a temperature
of 230°C at the compressor discharge.
7. The cold air disk can not work in a manual mode.
8. The air cycle machi ne is a hea ting unit consis ting of a co mpresso r and tur bine
on a common shaft.
9. As the air cools, its moisture content evaporates.
10. The water separator 2°C control system bypasses hot air around the air cycle
machine, if needed, to provide water freezing in the separator.
The order of words in technical English is very important. Technical English us-
es a lot of compound words or “noun clusters”, that is a chain of words, e.g. door
lever fuel tanks
ground servicing operations
left forward passenger door
nose landing gear uplock box
aft cargo compartment door
GRAMMAR: ATTRIBUTIVE CONSTRUCTIONS
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AIRCRAFT MAINTENANCE
qualifier
component
meaning
door
lever
lever of the door
fuel
tanks
tanks for fuel
upper
deck
deck on the top
discharge
valve
valve for discharging air
location
system/function
assembly/ function
sub-assembly
component
left
engine
mounting
bolt
washer
upper
rudder
servo
drive
rod
nose
gear
ground
safety
pin
brake disc
a disc on the brake unit
disc brake
a type of brake
flight level
aircraft standard altitude
level flight
horizontal flight
tank center
the center of the tank
center tank
the tank in the wing center box
proximity detector
outer RHflap track fairing
attachment bolt heads
The basic principle in a compound word is that one word is the component, or
“key word”, and the other words are the qualifiers.
When a compound word/expression is in a text (e.g. the Maintenance
Manual), the “key word” - the component - is the last word in the chain. The
words before qualify the “key word” with more and more specific information:
Remember that the “key word” is also the smallest item in the chain. The other
words only help to identify it. In a text, the “key word” is the last word in the
chain. But in a list (an IPL, IPC, etc.), the “key word” is usually the first word -
to make identification easier. It is followed by a comma or a dash, e.g.
box, uplock, nose landing gear
detector, proximity', aft cargo component door
relay, isolating, starter power
This word order is unusual in a text with a verb.
Careful! The sense of an expression depends on the word order. Look at these
examples. The “key word” is in bold type:
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UNIT 1. AIR CONDITIONING. OXYGEN
Definition
a
в
1. air used to cool hot air
air cooling
cooling air
2. to transfer from one circuit to another
switching circuit
circuit switching
3. procedure to check lights
light test
test light
4. signal sent back by the system
feedback system
system feedback
5. large groups (looms) of wires
wire looms
loom wires
6. non-return valve
check valve
valve check
7. motor to move a valve
valve drive
drive valve
8. activates a valve electrically
solenoid valve
valve solenoid
9. air from engine compressor
bleed air
air bleed
10. system that provides hot air
air bleed
bleed air
You must be methodical. Analyse the context. Your interpretation must be coherent. Don't translate too literally. Find the reality of the aircraft behind the text.
Exercise 5. Choose the compound expression which agrees with
the definition.
Exercise 6. Here are some common aircraft components in the incorrect order. Put them in the correct order. Look at the example:
Incorrect order: COLUMN CAPTAIN CONTROL Correct order: CAPTAIN
CONTROL COLUMN
1. handle control spoiler
2. system oxygen crew flight
3. unit display lower
4. bulkhead aft pressure
5. panel lighting exterior control
6. wing left fairing hand tip
7. edge right trailing upper
8. fuel integral tank
10. door cargo fittings lock
11. distribution cabin conditioned
system air aft
12. main doors gear
13. marker light inner
14. box gear nose interphone
i5. receptacle ground door access
power
9. recline button control
clamp – фиксатор
crimping – обжимание
deplete – опорожнять
Text B. OXYGEN
distribution tubing – распредели-
тельный трубопровод
filler valve – заправочный клапан
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AIRCRAFT MAINTENANCE
gage – измеритель
harness – бортовая кабельная
система
hose – шланг
lanyard – вытяжной фал
latch – замок, защелка
manifold – коллектор
manual shutoff valve – отсечный
клапан с ручным управлением
overboard discharge – сброс за борт
pressure reducing regulator – редуктор давления
pressure transducer – пневмодатчик
punch – перфорированное отвер-
стие
replenish – пополнять
safety relief valve – предохранительный клапан
shutoff valve –
перекрывной клапан
storage cylinder – аккумулирующий цилиндр
stow – размещать
striker – механизм переключения
The purpose of oxy-
gen systems is to provide oxygen to the
crew and passengers,
when required.
The crew oxygen system is supplied from a
storage cylind er located in the forward cargo compartment. A
manual shutoff valve
and system pressure
gage are provided in
the flight compartment. The storage cylinder, pressure reducing regulator, pressure transducer, and
overboard discharge components are located along the right sidewall of the forward cargo compartment. The distribution tubing runs al ong th e right sid ewall of
the lower body and rises through the control cabin floor at the P-6 panel. There it
passes through the crew shutoff valve and along the sidewalls and ceiling to each
crew member’s station. A depleted cylinder is replenished by replacement or re-
charged from the external filler valve.
Oxygen for the crew system is stored in a cylinder, at 1850 psi at 21C (70F). A
direct reading indicator on the cylinder provides cylinder pressure. The crew oxygen cylinder assembly includes a slow -opening shutoff valve, pressure indica-
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UNIT 1. AIR CONDITIONING. OXYGEN
tor, and safety relief valve. Quick release clamps support the cylinder and facilitate replacement when the oxygen is depleted.
Each crew member station is equipped with an oxygen mask/regulator stored in a
box which is secured to the airplane. When the mask/r egul ato r is stowed and box
doors closed, oxygen flow to the mask is prevented by a valve inside the box.
With the doors closed, the RESET-TEST LEVER on the left door holds this
valve closed. A flow indicator is on the opposit e side of the box from the valve.
It can be seen with doors open or closed. The pneumatic harness that holds the
mask to the face is deflated when stowed. The harness fits all head sizes.
The purpose of the passenger oxygen system is to supply, by chemical generators, gaseous oxygen to each passenger seat, lavatories, and cabin attendants
through passenger service units (PSU’s).
Passenger oxygen masks are stowed in a compartment within the overhead passenger service unit.
The compartment door is automatically unlatched by the flight crew or by a cabin pressure sensing switch to release the masks. The latch may also be manually
opened with a small punch.
The passenger oxygen latch mechanism is automatically activated by a solenoid.
The solenoid is controlled by eit her the p assenger oxygen switch on th e P5 panel
or by the pressure switch in J13. The latch is independent of the solenoid and can
be deployed manually. When activated, the solenoid deploys a striker downward
to release the latch.
Oxygen is generated inside the generator by the chemical reaction of sodium
chlorate and iron: - NaClO3 + Fe = NaCl + FeO + 02.
The core is shaped to provide maximum flow at starti ng. A manifold on the generator allows hoses to be connected to the generator. Either two, three or four
hoses can be connected depending on the size of the generator. The manifold
will rotate 360°to prevent hose crimping. A relief valve on the generator will release pressure at 50 psi. Normal internal pressure is 10 psi. The chemical oxygen
generators are manually activated by pulling the mask down. The lanyard attached to the mask pulls a pin that releases the activation pin to initiate the chemical reaction.
Exercise 7. Answer the questions.
1. What is the purpose of oxygen system?
2. How is the crew oxygen system supplied?
3. Where are the main components of the oxygen system located?
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AIRCRAFT MAINTENANCE
4. How is a depleted cylinder replenished?
5. What information does the indicator on the cylinder provide?
6. What is each crew member station equipped with?
7. What size does the harness fit?
8. Where are the passenger oxygen masks stowed?
9. How can the latch be opened?
10. how many hoses can be connected to the generator?
Exercise 8. Read how to skim a text and try to do the task.
Skimming a text is a fast reading technique to look for main ideas in a text.
Skimming is used to obtain the gist (the overall sense) of a text.
Do the following tasks:
- read the title, subtitles and subheading to find out what the text is about;
- look at the illustrations to give you further information about the topic;
- read the first and last sentence of each paragraph;
- don't read every word or every sentence; let your eyes skim over the text,
taking in key words;
- continue to think about the meaning of the text.
AIRCRAFT FIRE RISK FROM BATTERY-POWERED
ITEMS CARRIED ON AIRCRAFT
Many battery types are categoried as Dangerous Goods in the applicable ICAO
Technical Instructions and also in the IATA Dangerous Goods Regulations. Th e
Regulations are intended as a field document and have no legal standing but have
been developed from the ICAO Technical Instructions which are the legal
framework and are compatible with them, although sometimes more restrictive.
This categorization as Dangerous Goods has been made because of the risk of
fire from spontaneous battery ignition, whether batteries are installed in equipment at the time or not, and also because in some cases it is not p ossible to co ntrol any such ignition which might take place on aircraft using the fire control
methods available. However, most of the batteries types carried by passengers
for their personal use are routinely permitted under the “excepted quantities”
provisions. The exact limits of such concessions may be more restrictive than the
minimum provided by ICAO according to the domicile of a particular carrier, or
according to rules set by the carrier itself. Permitted carriage is usually predica ted upon quantity, typ e of flight (passenger or non-passenger) and, for passenger
flights, whether the items are the cabin or checked baggage of passengers travelling on the same flight. Where spare or loose batteries are permitted, they must
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UNIT 1. AIR CONDITIONING. OXYGEN
be carried or packed in such a way that they are protected from damage and short
circuit. Short circuiting of any charged battery and subsequent overheating or
sparking can occur if a metallic path capable of conducting electricity is established and maintained between terminals of opposite polarity.
General Provisions
Dry cell alkaline batteries, incl uding the common AAA, AA, C, D, 9-volt and
button cell types and dry cell rechargeable batteries such as Nickel Metal Hydride (NiMH) and Nickel Cadmium (NiCad) represent much lower quantifiable
risk of fire provided that precautions against unintended activation or short circuiting of the terminals in loose packed batteries are taken. However, lithiumbased batteries can be extremely flammable because of this and the much greater
power contained within and are subject to restrictions on carriage both as cabin
and checked baggage.
Lithium Batteries
These are the type of batteries that most often feature in on-aircraft incidents. Often it is overheating, which eventually triggers ignition in equipment and batteries that, unknown to t he user, are faulty in s ome way. However, various origins
of overheating have been identified during investigations.
There are two principal types of lithium battery. Lithium metal batteries and
Lithium ion batteries. Lithium polymer batteries are a kind of lithium ion battery
and so are also included in that category. Fires arising in th e Lithium Metal type
cannot necessarily be extinguished using fire suppression equipment currently
carried on aircraft. For this reason, the maximum permitted lithium content of
this type is much smaller than for lithium ion types. However, when installed in
serviceable equipment, the risk of overheating is assessed as low for both types
and they may, in most circumstances, be carried by passengers in either cabin or
checked baggage. No spare or loose lithium batteries of either type are usually
permitted in accompanied checked baggage.
Lithium Metal batteries (also referred to as non-rechargeable lithium or primary
lithium) are batteries that cannot be recharged and are designed to be thrown
away once their initial charge is used up. They are often used in cameras and in
other small personal electronics. Consumer-sized batteries of these types - typically those containing up to 2 grams of lithium per battery (which includes all
the usual non-rechargeable batteries for personal film and digital cameras such as
AA, AAA, 123, CR123A, CR1, CR2, CRV3, CR22, 2CR5, etc. and flat/round
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AIRCRAFT MAINTENANCE
lithium-button cells) are not usually subject to restrictions in personal-use quanti ties. Passengers are usually prohibited from carrying larger batteries of this type.
Lithium Ion batteries are also known as rechargeable lithium, lithium polymer,
LIPO or secondary lithium batteries. They are always mains-rechargeable and
are normally found in laptop and net book computers, digital cameras, camcorders, cell phones, P DAs, and radio -controlled to ys and games. They may take the
various forms including the s tandard AA, AAA, and 9-volt t ypes. The degree of
potential fire hazard from a lithium ion batteries increases in direct proportion to
the amount of lithium it contains. However, since few batteries display this information, an approximate equivalence has been developed which links the watthours of battery power with the lithium content of these batteries. The watt hours
(wh) which a particular battery provides can be checked by multiplying the pla carded milliamp hours (mAh) by the placarded volts (V). Lithium content is approximately 8 grams per 100 watt hours. Most lithium ion batteries currently
available to consumers have a power output below 100 watt-hours and the number of these that can be carried in pa ssenger baggage when install ed in equipment is not limited. A small number of very large / extended life computer laptop
batteries and some batteries used for powering professional audio-visual equipment have ratings of up to 160 watt -hours and are usually restricted to a maximum of two per passenger. For lithium contents greater than this, there are no
concessions for carriage in passenger baggage.
It should be noted that some more complex issues may be raised if passengers
are able to connect their battery powered equipment to an aircraft power source
since such action usually has the concomitant effect of initiating a recharge of
the battery supply. At the first hint of battery overheat – the equipment feeling
hotter than usual or a ‘hot’ smell – the power cable should be dis connected and
the equipment placed in view.
As lithium ion batteries are rechargeable they represent the greatest number of
batteries on a passenger aircraft. It is entirely possible for a single aisle airline r
with 140 passenger seats to have in excess of 500 lithium batteries onboard. This
presents a threat not only due to the number but also to the potential difficulty in
gaining access during a thermal runaway/overheat. Regulators are updating
guidance to crewmembers in the best actions to fight such fires. Movement of
overheating electronic devices can cause adjacent cells to overheat resultin g is
high-energy expulsion of extremely hot gel and parts of the device acting as
shrapnel. It is therefore imperative that adequate protection of the crewmember
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UNIT 1. AIR CONDITIONING. OXYGEN
acting as the firefighter be provided. Only if adequate protection is available
should a device be moved.
Cooling an overheating device is the only way to stop the thermal runaway. W ater or other non-alcoholic liquids in large quantity will be necessary. The crew
must consider the potential collateral damage of a large amount of liquid. If, in
their professional opinion, it is a safer course of action to move the device, protection of the firefighter and a clear plan of where to contain the device must be
accomplished. During thermal runaway lithium batteries will emit significant
amount of organic vapor (looking like smoke) it is a mucous membrane irritant
and high flammable. In addition the odour of th ese fumes is noxious and very
unpleasant. Containment of the device to eliminate fumes and the potential inj ury by additional cell discharge is essential.
BIRD STRIKE ON FINAL APPROACH:
GUIDANCE FOR FLIGHT CREWS
Editor's Note: This article discusses the issues and thought processes associated
with a bird strike on final approach. Crews should follow company approved
emergency procedures (e.g. Company Operating Manual) and manufacturers
guidance regarding the conduct of the flight, and management of aircraft systems, when such an event occurs.
Description
This article provides specific guidance regarding the response to bird strike while
on final approach.
Scenario 1
An aircraft is hit by birds while on final approach to land - should the pilot continue the approach or initiate a goaround/missed approach? Having encountered
birds, the question to be ans wered is "what is the da mage to the aircraft and what
effect will this have on the safe conduct of the flight?" The full extent of any
damage, to the engines and/or the control surfaces and landing gear, may not be
apparent until applying pow er, configuring, or manoeuvring the aircraft. It might
therefore be the case that, if a go-around is initiated, the pilots rapidly finds
themselves in a situation where the runway is disappearing beneath them but the
aircraft cannot safely fly a missed approach. Therefore, in the above scenario, it
is advisable to continue the approach and land.
Scenario 2
A pilot sees a flock of birds ahead of him on final approach - should he continue
the approach or initiate a go-around/missed approach? Having seen the birds, the
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AIRCRAFT MAINTENANCE
question to be answered is "if a go-around is initiated, how likely is it that the
aircraft will avoid a bird strike?" There are two matters to consider. Firstly, the
behaviour of birds towards an aircraft in flight is highly unpredictable and varies
greatly by species, some waterfowl species typically dive but such behaviour is
not consistent and the birds may fly upwards, potentially into the path of the aircraft initiating a go-around. Secondly, the greater the engine thrust, the greater
the damage caused by ingesting birds - it is probable that less damage will be
caused if the birds are hit while the engines are at low speed or idle. Therefore,
in the scenario described above, unless a go-around can be achieved with a reasonable degree of confidence that the aircraft will not hit birds, it is less hazardous to continue the approach to land.
Accidents and Incidents
Here are some examples of bird strike events, not necessarily on final approach,
that have caused significant airframe or engine damage:
Significant Airframe Damage
734, Amsterdam Netherlands, 2010 (1) (On 6 June 2010, a Boeing 737-400 being operated by Atlas Blue, a wholly owned subsidiary of Royal Air Maroc, on a
passenger flight from Amsterdam to Nador, Morocco encountered a flock of
geese just after becoming airborne from runway 18L in day VMC close to sunset
and lost most of the thrust on the left engine following bird ingestion. A
MAYDAY was declared and a minimal s ingl e engin e cl imb out was follo wed by
very low level visual manoeuvring not consistently in accordance with ATC radar headings before the aircraft landed back on runway 18R just over 9 minutes
later.)
B734, Barcelona Spain, 2004 (On 28 November 2004, a KLM B737-400 departed laterally from the runway on landing at Barcelona due to the effects on the
nosewheel steering of a bird strike which had occured as the aircraft took off
from Amsterdam.)
B738, Djalaluddin Indonesia, 2013 (On 6 August 2013, a Boeing 737-800 encountered cows ahead on the runway after landing normally in daylight following an uneventful approach and was unable to avoid colliding with them at high
speed and as a result departed the runway to the left. Parts of the airport peri m eter fencing were found to have been either missing or inadequately maintained
for a significant period prior to the accident despite the existence of an airport
bird and animal hazard management plan. Corrective action was taken following
the accident.)
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