02 airframes notes (atpl)

7/25/2019 02 Airframes Notes (ATPL)

1/48

Ground School Day 1 12/29/2015

Types of load

Static: Steady load of some intensity throughout

Dynamic: Varying intensity and direction for

Cyclic:

StressStress is the internal force per unit area inside a structural part as a resultof tension: ension! Compression! orsion! Shear! "ending

Wing (Main Plane)Stress - Bending#n ground: $ings droop due to fuel! engine and its o%n %eight& 'ppersurface under tension and lo%er surface under compression&(n flight: $ings )end up%ards due to lift forces& 'pper surface no% undercompression and lo%er surface under tension&

o mitigate %ind )ending stress in flight

$ing mounted engines

*uel 'sage: Centre tan+ then %ing tan+s ,in)oard then out)oard! if

applica)le-

.ileron 'p *loat: Crude drag inducing deice

Pressurization Stressoop ,adial- and .ial stress

Stressing a material may cause it to change its shape or to deform&his change or deformation is +no% as S.(3&(t %ill go )ac+ to its original dimension proided the change is %ithin its4lastic imit&


2/48

Station numbers

Attachment methodsieting! $elding! .dhesie )onding! "olting!6inning

Material Properties

4lasticity

.)ility to change its shape reersi)ly %hen su)7ected to certain

loads or forces

6lasticity ,or Ductility-.)ility to deform irreerisi)ly under force or load

Stiffness / igidity.)ility to %ithstand reersi)le deformation under load

Strengthesistance to damage

!imit load

Design limit load8aimum load the airframe or component is designed to eperience in

serice


3/48

Design 'ltimate oadoad %hich the structure must %ithstand %ithout collapse

Safety *actor

D'/D

System "esign Philosophy

Safe ife

he structure is gien a life of hours and/or landings or

pressuriation cycles and must )e remoed from serice %henthe appropriate criteria are met&

he life is )ased on fatiue assessment and aircraft role& he

fatigue life must )e recalculated if a change in aircraft role isproposed&

Can a long haul airplane )e used for short sector flights on a long term)asis; 3o! hae to re assessShort term solution for shortage of aircraft; 6ossi)ly

*ail Safe

6hiliosophy anticipates a possi)le failure %ith minimum

(f one component fails! the ad7acent components ta+e up the

load for a limited period of time! usually until the net sericeinspection&

Damage tolerant

Does not hae specified life

a+es structural %ea+ening into account

oading spread oer larger area

Damage can )e detected during the normal inspection cycles

)efore a failure occurs


4/48

*atigue

he life of an airframe is limited )y fatigue %hich is caused )y

load cycles eperience during ta+eoff! landing and pressuriation&

$ohler ,S/3- Cure leads to fatigue

'se less load! more cycle

he more the applied alternating stress! the lesser the num)er of

cycles )efore it leads to fracture

#oc$pit %indo%s

oughened glass %ith inyl interlayers %ith ru))er sealing

Coc+pit %indo% heating

Conductie film applied to inner surfae of outer glass pane toproide electrical heating for anti


5/48

6assengers %indo%s ,6hoto-

8ade of 6lastics ,6erspe-

6assenger Door 6lug ype ,oc+ing 6ins-

Cargo Door

atch type/inge

Pressure Bul$heads

'npressurised areas: 3ose gear "ay! .ir Conditioning

Compressor! 8ain Gear "ay! ail Cone

ail S+id / ail stri+e might damage and depressurie tail cone

*loor Venting ,"lo% out panels-

Decompression in the cargo )ay leads ca)in pressure difference

and ca)in floor might collapse! leading to actiation of the )lo%out )ungs

Aluminium Alloy

Duralmin

.luminium and Copper Good Strength to $eight ratio

6oor corrosion resistance


6/48

Good thermal and electrical conductiity

6oor %elding capa)ility

&ther metals

Steel

anding gear

itanium

ighter than steel

Strong and high corrosion resistance

Can %ithstand high temperatures

'sed in high temperatures areas li+e engine compartment for fire

protection

8agnesium alloys 4cellent strength to %eight ratio

6oor elastic properties

3ot used in primary structures

#omposites,in the form of laminate or sand%ich a+a honey& educe oerall airplane %eight


7/48

Disadantageous1& a+es time to cure

ypical composite materials2& *i)erglass

>& Car)on fi)er=& .ramide ,?elar-

heir composition:

8atri ,esin or *iller-%hich are )asically )inders

*i)res %hich are reinforcements

Anisotropic8eaning %e can tailor to the direction of the loadStiffness of composites depends on the panel design li+e the composition

of the constituents&

'sotropic.luminium or steel hae the uniform stiffness regardless of the directionof the load&

Sand%ich structure composite

%o thin )ut stiff s+in sheets and a light %eight )ut thic+ core

he core! normally of lo% strength material! proides high )ending

stiffness %ith oerall lo% density due to its thic+ness& (t also sta)ilies thecoering sheets&


8/48

'nsuita)le for a)sor)ing concentrated loads&

uselage #onstruction

hree types:

russ Contruction! normally %ith fa)ric s+in @Diagonal )race and

ongeronA

8onocoue Constuction

o S+in a)sor)s all the load

o Cylindrical shape for maimum stiffness

o *ormers or *rames are for shaping& (t does not support any

load

Semi


9/48

Wing construction #antile*er monoplane

Wing construction - #omponents

1& $ing sparsa& 8ain load )earing mem)ers of the %ing)& 8ain spar B thic+est section of the %ing

2& i)s ,hae holes in them to lighten the %eight->& S+in

a& *ormers that proide the %ing %ith cross sectional shape)& ae holes to reduce %eightc& ransfer some load from s+ins to the spar

=& Stringer

Torsion Bo+ or Bo+ SparSpurs )uilt into a )o shape %ith reinforced s+in forming the upper and

lo%er sides of )o

S$in

8ore suited to a)sor)ing stress under tension than under

compression %here )uc+ling tend to occur

Stringers

ong thin mem)er that runs the length of the %inf under the s+in

.)sor) some of the )ending load

elp stiffen the s+in against )uc+ling


10/48

,mpennage

Consists of ailplane and *in

Similar to %ing construction

Wing mounted engines *s Tail mounted ones ail mounted engines more prone to stall )ecause of the shift in

CG

$ing mounted engines more prone to ya% in case of single sided

engine failure

Probability of ailure #ondition and Se*erity ,(nsert 4.S.

chart-

Duple! riple

ard Time Maintenance (different from Safe !ife. in specific toindi*idual component)

ard ime maintenance is a primary maintenance process under

%hich an item must )e remoed from serice at or )efore aspecified time for inspection or oerhaul

.lso +no%n as ime "et%een #erhaul ,"#-

&n #ondition Maintenance

his is a preentie primary maintenance process %hich reuires

that a component )e periodically inspected or chec+ed against

some appropriate physical standard or limit to determine%hether it can continue in serice&

(f the limit is eceeded! the part has to )e replaced

(t is not a philosophy of fit and forget or fit until failure&


11/48

Pascal/s !a%

6ressure E *orce / .rea

*orce E 6ressure .rea

$or+ Done E *orce Distance

6o%er E $D / ime

E *orce Distance / ime

E 6ressure .rea Distance / ime

E 6ressure Volume / ime

8echanical .dantage

he use of a small force to create a larger force else%here


12/48

ydraulics Applications

"ra+es

*laps

anding Gear ,etracta)le-

*light Controls "y conerting pressure energy into mechanical %or+s ,through

actuators-

$hy is hydraulics )etter than 6neumatics

iuid is imcompressi)le

iuid transmits pressue eually

.ir can )e compressed )y 99&F5 of its oulume

.ir is springy

.is has time lag .ir B lea+s are difficult to detect

.ir B not suita)le for heay loads

3o return line needed in pneumatics ,adantage-

ight %eight and no fire haard ,adantage-

Summary

ydraulics is used to conert pressure energy into mechanicalH

ydraulics luid properties

Good lu)rication

o% iscosity

$ide operating temperature range

3on corrosie

Sta)le

3on toic

igh flash point ,if-

Types if hydraulic fluids 8ineral

Synthetic


13/48

8ineral )ased ,D4* S.3 91


14/48

Acti*e 1 Passi*e ydraulics Systems

.ctie system: 6ump reuired

6assie System: 3o pump

4ample: ight aircraft )ra+ing system

Simple ydraulic System

1& eseroir B Standpipe / Stac+pipe is to preent total lea+! stac+pipeleel

2& 6ump>& *ilter! out contaminants / sediments=& 6ressure regulator5& .ccumulator! store it as gien 6S(K& Chec+ ale / 3on return ale! #ne %ay ale ,3V-F& and pump , for ground sericing or manual sericing of cargo doors-

I& 6ressure gauge ,to preent oer pressure in system-9& elief ale10& Selector ale11& .ctuator ,inear/otary-

Scre%7ac+s B Drien )y hydraulic motors ,otary-

ydraulic System Pressureo% 6ressure Systems: 'p to 2000 psiigh 6ressure Systems: >000 psi or higher


15/48

2eser*oir

6roides storage space for system fliud

6roides a resere to compensate for minor lea+s in the system

.llo%s for ariation in fluid olume due to thermal epansion and

actuator operation

6roides space for returning fluid

6urges system of air ,preents caitation %hich ma+es )ra+es

unresponsie-

8ay )e pressuried or 'npressuried

6ressuried )y air from engine )leed ,typically 100psi-

o o gie positie head pressure to pump (nlet

o 6reents caitation

o 8inimise foaming ,preent slushing-

ypes of ydraulic pumps o% pressure pumps

o S6' G4. type

o V.34

igh pressure pumps

o 6iston ypes

Constant Volume

6ump Volume output is fied

. pressure regulator is reuired to unload the

pump %hen system pressure is reached! andthe accumulator maintains the pressurethereafter

Constant 6ressure ,Varia)le Volume-

6ump olume output is aria)le according to

system reuirements to maintain pressure& Self regulated )y output pressure and piston

acting on the s%ash plate angle


16/48

ilter

ocated 7ust after the pump

*ilter solid particles L 25microns

$hen pressure )uilds up to a certain alue! a *(4 "M6.SS%arning %ill come on to %arn of an impending )ypass

#n some system! a red )utton indicator %ill pop up for engineers

to rectify

Pressure 2egulator

.lso +no%n as .uto Cut


17/48

1& *lo% only in one direction2& 6reents )ac+ flo%>& .rro% indicate on the ale to state its flo% direction

andpump

'sually dou)le acting pump

'sed in emergency on smaller aircraft and for ground operation

and maintenance on larger aircraft

Pressure 2elief 3al*e

Safety deice to protect system from oer


18/48

ydraulic use

'nder normal operation condition! fluid is allo%ed to pass through

the fuse&$hen there is a lea+! there %ill )e a pressure drop )ehind the

piston forcing it to close&

light "ec$ Warning 'ndicators

o% fluid Nuantity

igh emperature

System 6ressure o%

6ump o% 6ressure ight

&pen #entre Selector 3al*e

*itted on older light aircraft! serices connected in series

#nly one serice can )e operated at a time

$hen no serice is selected! the fluid passes though the centre

of the open centre selector

$ith a serice selected and actuation completed! the selector

automatically returns to open position

$hat happens if it did not return to open position; 6ressure relief

ale %ill actuate&

#losed 1 Pressurized System

'nloading ale ,6- maintains pressure at deisng alue Junloads pump )y directing fluid )ac+ to reseroir

#perating pressure manintained in the line leading to selector

ale )y accumulator

Can operate multiple serices simultaneously


19/48

i+ed !anding 5ear

ricycle

ail %heel ,ail dragger-

Ad*antages of a Tricycle configuration

4asier to steer

ess li+ely to nose oer in a cross %ind

"etter for%ard ision particularly during taying

Types of undercarriage Shoc$ absorption

4lastic "ungee

eaf Spring Cantileer

#leo


20/48

(ndication system

$arning system

4mergency lo%ering system

2etractable !anding 5ear 'ndications 'p and loc+ed ,3o light-

(n transit! Disagreement %ith Gear eer position! 'nloc+ed

,steady ights-

Do%n J oc+ed position ,Green steady lights-

!anding 5ear &perating SpeedsVloB 8a speed at %hich gear can )e operatedVleB 8a speed at %hich aircraft can )e flo%n %ith gear etended

6ploc$ oo+ feature

#nce landing gear is hoo+ed and loc+ed! hydraulic pressure is

not needed

"o%nloc$

#er


21/48

.ll these are sensed )y .ir/Ground sensors! also +no%n as Suate

s%itches

5ear "o%n Safety !oc$

#n the ground! leer held in D3 position

o 5ear "o%n Pins

emoe )efore flight

0ose %heel

Tyre Sections

Cro%n < hic+est part& Designed for %ear and tear

Shoulder < 3ot designed for %ear and tear

Side%all < hinnest and %ea+est section& .oid doing tight turns

%ith loc+ed inner main %heel "ead < o fit against the rim of the %heel& 6reent air lea+age

Ply 2ating - (nde of type strength

Speed rating 8a speed on ground in mph

A7uaplaning

ayer of %ater lifting the tyre from the run%ay surface reducing

the )ra+ing effect

#ccurs %hen tread depth is completely filled %ith %ater

#ccurs at 9 times the suare root of the tyre pressure ,psi- E

speed in +nots

1 8pa E 1=5psi


22/48

Greatest stress on the tyre is during the touchdo%n& (t can cause

creeping&

ight turns induce ecessie stress on tyre side%all ,and torue

lin+s-

Tyre

u)e tyre

o 6ro)lem %ith tyre creep! %hich can cause damage to

inflation ale and cause a )lo%out& ,ale shearing-o (nternal friction )et%een the tu)e and the tyre! generating

heat

u)eless tyre

o ighter

Creeping can )e descri)ed as

"isc Bra$e System

usible Plug 1 Thermal plugB elease air in eent of oer& #utflo% Vale 8otor/ .ctuators=& 6ressure Controller

5& 4cessie Differential 6ressure elief ValeK& 3egatie Differential 6ressure elief Vale

"ifferential PressureDifferential pressure is the difference )et%een the ca)in pressure andoutside am)ient pressure

he higher the pressure differential the higher the stress on the fuselagestructure

?eeping the maimum differential pressure to a practical minimum %illreduce this stress

herefore the structural strength of the aircraft %ill determine itsmaimum Differential 6ressure

ypical 8aimum Differential 6ressure of large modern aircraft is a)out 9-:


29/48

Modes of #abin Pressurisation1& (so)aric 8ode ,Constant 6ressure / Ca)in .ltitude-2& 8aimum ,Constant- Differential 6ressure 8ode

WarningsCa)in altitude %arning horn %ill sound %hen ca)in altitude eceeds10!000 ft$hen ca)in altitude reaches 1=!000ft! passenger oygen mas+s %ill drop

Safety 3al*e 1 Pressure 2elief 3al*eo protect aircraft from structural damage from ecessie positiedifferential pressure

Safety ale opens %hen ma pressure is eceeded )y 0&25psi

euirement for 2 ale installation

0egati*e "ifferential pressure$hen am)ient pressureL ca)in pressure*uselage su)7ected to crushing effect.ircraft fuselage not designed to ta+e compressie loadsVale opens %hen outside pressure eceeds ca)in pressure )y 0&5


30/48


31/48

(cing Condition eists %hen:

emperature is P10 deg Celsius and )elo% ,otal .ir emp in

flight and #. on ground and ta+eoff-! .3D

Visi)le moisture ,clouds! rain! sno%! sleet! mist and fog- is

present

'ce "etection

SmithOs (ce Detector

osemount (ce Detector ,>5+-! $ith icing! sensitiity %ill

decrease

Areas that are protected against icing

4ngine (nta+e ,and some (nlet 6ro)es-

$ing eadig 4dges ,Slats and *laps-

6ropellers $ater $aste Drain 8asts

6itot u)es ,some Static 6orts-

Coc+pit $indo%s

Stall $arning Vanes

#lassification

.nti


32/48

Methods

8echanical

hermal

iuid

Anti-'cing and "e-'cing Systems

1& 8echanical

De& *luid

6ropellers! $ing! $indscreens

"e-icing boots

(nflata)le ru))er mats

#n %ings and some tail surfaces

(nflated alternatiely and symmetrically

#perated %hen ice thic+ness reaches 1&5cm

Mechanical "e-'cing Boots

1& (nflation .ir Source:

6ressure side of acuum pump

4ngine )leed air


33/48

igh pressure reseroir

2& Deflation source:

Vacuum pump

Venturi of e7ector nole

"e-'cing Boots "isad*antages

(ncrease in drag

igher maintenance cost! possi)le )oot lea+

"e-'cing Boots

1 cycle ta+es >= seconds

ime interal )et%een cycles:

(G: 20K sec

4.VM: 2K S4CS

Thermal (Bleed Air)

Common on large modern aircraft

(ce protection for engines and %ings

.ir ducted from engine compressor

Small 6enaltyH loss of thrust

.erofoil eading 4dges

6itot! %aste %ater ehaust

*ront glass shield


34/48

4ngine inta+e and pod

Thermal (electrical Systems)

6ropellers: 4 of )lade and root! spinner cone

eating mat coers 1/> of )lade length from root

$indscreen heaters

6rotect against interior fogging

8a+e %indscreen more resistnant to )ird stri+es

Speed may )e limited to 250 +nots )elo% 10!000ft if system is

inoperatie

eating elements

for pitot pro)es! some static ports ! angle of attac+ panes ,alpha

pro)es- and temperature pro)es&

*ront %indo%: .nti5deg

luid Systems "e-icing Systerms

*luid de


35/48

5round "e-'cing

2ain protection

$indshield $ipers

ain epellanto 'sed in ery heay rain %hen %ipers alone is not effectie

o .pply to one %indo% at a time

3ot to )e used on dry %indshield

6ermanent rain repelling coating layer on %indshield during

manufacture

#RMG43 SMS48S

Supplemental #ygen

Carried in pressuried aircraft in case of emergencies

Safety 6recautions

Care must )e ta+en %ith the use of oygen systems

1& Control ales must )e opened slo%ly ,friction may cause

com)ustion-

2& Contact %ith grease or oil must )e aoided as it can result in a

chemical reaction leading to a spontaneous fire or eplostion

>& Smo+ing is strictly prohi)ited

light #re% Supplemental &+ygen

Stored in the cargo


36/48

"iluter "emand regulator,*light Dec+-

Supply oygen only on demand

4cept %hen in emergency and test positions

"iluter "emand 2egulator

Pa+ and cabin cre% supplemental o+ygen

Chemical generator or high pressure gaseous ,cylinder tan+s-

type

Continuous

Ca)in air is mied %ith oygen

o (t does not gie protection against smo+e and fumes

6a serice units ,6S's- opened automatically at 1=!000 ft&

Chemical generator type opened electrically )y solenoids

Gaseous type opened pneumatically

#hemical 5enerator Type

8inimum 15min oygen supply

#nce process started! cannot )e stopped

(ndicator changes colour from orange to )lac+ once used

.dantages

ight

(nepensie

3o maintenance

ong shelf ife


37/48

Gaseous ype

Self contained

efilla)le

Can )e regulated and )e turned off

irst aid Therapeutic &+ygen

*irst .id #ygen ,6orta)le )ottles- are meant to proide some pa

%ho may reuire additional oygen after an emergency descent due torespiratory pro)lems

#r

o deal %ith pa %ith medical conditions li+e respiratory disorders

during normal flight

.dditional )ottles M6ST )e carried for pa %ith +no%n medical

conditions

lo% rate

= litre flo% for first aid use B >0 min

2 litre flo% for post decompression %al+ around B K0min

Protecti*e Breathing ,7uipment (PB,)

6"4s must )e aaila)le to all cre% mem)ers

Deice must )e a)le to protect the eyes! nose and mouth for

15minutes

(t can )e a porta)le oygen )ottle %ith a full face mas+ #r a smo+e hood

#r coc+pit oygen mas+ %ith smo+e goggles

#re% portable &+ygen %ith full face smo$e mas$ ("emand

Type)


38/48

PB, Smo$e hood

ire Triangle

> elements are reuired to start and support a fire

*uel #ygen

eat

"etection of smo$e ; ire

"y Visual

Smo+e detectors

#erheat detectors

Smo$e "etectors

"elly Cargo and "aggage Compartments .ionics Compartment

aatory

8ain Dec+ Cargo Compartments ,*reighter and Com)i .ircraft-

Smo$e "etector &ptical

$hen smo+e is present! the light %ill )e refracted and sensed )y thephoto electri cell %hich %ill then produce a oltage to )ring on the smo+e%arning

Smo$e "etector 'onization

he air )et%een the 2 plates is ionied )y the radioactie source

and made electrically conductie

$hen smo+e is present! the conductiity is decreased and this is

sensed )y the control circuit to )ring on the smo+e %arning


39/48

&*erheat "etectors

4ngines

.6'

$heel %ells oilet $aste "in

&*erheat type detection

'nit type detector

o "i


40/48

Center electrode! conductie capillary! *iller material! hermistor

8aterial has a negatie co


41/48

*or .6'! if systems detects a fire on the ground %hen )oth

engines are off! it shuts do%n the .6' automatically anddischarges the etinguishing agent& ,(t assumes there is no onein the flight dec+ and plane is on ground-

ire %arning indication re7uirements

1& .ural

"ell! +laon or repetitie chime

2& Visual

8aster %arning caption

Steady red light for the .6'! the appropriate engine or

compartment>& est circuit to chec+ for continuity of the loops as %ell as the %arning

systems

,ngine ire ,+tinguishing Systems

%o shots must )e proided

%o )ottles per engine or one )ottle per engine %ith proisions

for %ither )ottle to )e discharged into the other engine

,+tinguishing Agents ,ngine and #argo #ompartments

*reon B "8 alon 1>01

Very effectie flame fighting

When pushed (0ormally guarded) .ural %arning is cancelled ,if not already cancelled )y pressing

the 8aster $arning-

Sui) is armed

espectie generator is deactiated

*uel! ydraulics! .ir "leed ales are closed ,isolating the

engine-


42/48

S7uib

(s a small eplosie cartridge ,electrically operated-

'pon detonation! the piston is forced do%n to allo% the

etinguishing agent to )e discharged into the selected engine

Thermal discharge

Discharge due to ecessie pressure %ill result in the am)er

discharge light illuminating

.t the same time! an oer)oard discharge dis+ %ill )e isi)le on

some aircraft type on the outside %hen you do your %al+ around

2'5'" 6,! TA0

02 airframes notes (atpl)

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