Note

structure

Q pot reduces the range of movement as the speed increases

Cable system have better strength/weight ratio Detent breaks out at 35 lb force. Fair leads – little or no change in direction Fair leads are not lubricated Turn buckle are tension rod and barrel rod type, in barrel

rod – all the threads are buried in the barrel Fixed tab is adjustable only on the ground. Controllable trim tab Servo tab has problem at low speed, which is overcome by

spring tab Spring tab – it operates at higher airspeed only. At low

speed, control system moves the control surface directly. Aerodynamic balance- pressure balance and balance panel

and etc Differential ailron – inside ailron creates more drag than

outside ailron during turn. Ailron upfloat – disadvantage of continuous drag and

slight negative lift All flying tail plane – less drag and more rigid Spoilers – fitted forward of flaps Spoilers – automatic extention fro aborted take off only

when wheel speed is higher than 70 knot

Ground effect spoiler retraction by speed brake lever or throttle lever out of idle position

Flap load relief by blow back valve Fowler flap stall angle 15 degree Kruger flap stall agnel 25 degree Slats and kruger – nose up pitching moment and center of

lift moves forward Slat – pantograph linkage Ruddervator - one moves up and other down for rudder

effect Freedom of movement check – force required to operate

the controls with spring balance attached to control column

Range of movement check by inclinometer or rule Double slotted fowler flap – lift by 100 % and stall angle to

20 degree Painting radaome – use non metallic acrylic Cs 25 large aircraft Minimum factor of safety is 1.5 Safe life is normally in flying hours and associated with

primary structure Critical part list Wing top skin panel 7150 or 7050, zinc based Landing gear attachment fitting is forged 7010 Grp is glass reinforced plastic

Nomex is Kevlar Glare is metal/composite sandwich Secondary structure has alternate load paths Wing attachment by bolts or butt straps Buttock line – width measuring either side of center lin e Major zone,subzone and zone – third number is zone or

component Windscreens are electrically heated to prevent icing and to

increase toughness of windscreen at low ambient temperature

Windscreen must withstand an impact of 4 lb bird at cruise speed at sea level

Windscreen may be glass or polymer or composite Pressure is maintained by outer pane on window Hatch may be operated from inside as well as outside and

it is inward opening Décor panel on door Plug type door fits into the frame from inside If there is a door failure but it locks securely, then aircraft

may be dispatched with reduced passenger compliment and no pax near door

Pressure sensing flap prevents lever being operated when the aircraft is pressurized

Engine pylon – primary and auxiliary structure Lateral and longitudinal datum lines pass through cg

Paint – vehicles cements the pigments together and pigments give color, solidity , hardness

Spar – front, main and rear or auxiliary Engine chine/strake

Air conditioning

Ram air is filtered and heated prior to entering the cabin Catalytic convertor is between engine tapping and prsov Bootstrap – turbine, compressor and heat exchanger Brake turbine –charge air to precooler to turbine, then to

cabin Water extractor is before cabin Temperature control – manual control permits overriding

of automatic control Maximum differential pressure is 9 psi Cabin climb rate is lower than aircraft climb rate A person shouldnot fly 24 to 48 hours after being

pressurized

Instruments Desynn system – permanent magnet and stator windings

on indicator Torque synchro – ac supplied to rotor coils Dead weight tester – plunger is screwed in until the mass

carrier is pushed up and spins freely. Mass carrier is above piston

Blockage of static source – altimeter and vsi constant and asi dangerously inaccurate

Blockage of pitot source – asi useless Leakage of pitot pressure- asi underreads Sensitive altimeter – tow or more capsules in series. And

temperature compensation is provided by bimetallic strip fitted between capsule and transmission shaft

Qfe set on subscale, altimeter will indicate height above airfield.

Servo assisted altimeter – it has less lag Instrument error – small tolerance in moving parts of

instrument Temp error – 4 percent for 10 degree During climb, blocked static source causes asi underread

and blocked pitot source causes asi overread Machmeter during climb – if static source blocked it

underreads and if pitot blocked, then difficult to predict

Vsi – capsule contract to indicate rate of clmb Laser ring gyro – time difference between laser beam is

proportional to the rate of rotation and produces digital readout

Direction gyro erection – air is exhausted onto the wedge attached to the outer gimbal,

Gimbal error –when gimbals of gyro are not mutually perpendicular and gyro itself is displaced

Advantage of dg is that it doesn’t suffe from turning and acceleration error of the magnetic compass

Acceleration error is due to erection unit of pneumatic driven attitude indicator .

Compass is made aperiodic by compass fluid and using several small powerfull magnets instead of single powerfull magnet

Deviation is angular difference between compass north and magnetic north

Electrical

Battery

Lead acid – gasing occurs towards the end of charging ni-cd – cellophane separators, oxygen at positive plate due to gasing no gasing during normal discharge

advantages – low internal resistance, high peak performace, higher charging rate and wide operating temp range

battery room test – capacity test, cell balance , insulation and cell vent pressure

insulation test between cell and battery case 1 megaohm for lead acid and 10 megaohm for ni cd

57 degee c is high temp indication and 71 degree will inhibit the battery to suppy emergency bus

Battery charging current flows through reverse current cb and if excess cureent , it trips

Constant current charging – greater water loss on overcharge

On shut down of engine, generator is taken off line by under voltage

If battery is switched out during flight, then battery bus is isolated from the battery

Dc motors and generators Low insulation resistance when hot Insulation test – all terminals together and frame , 0.5

megaohm Differential cut out switch – repulsion takes places Overvolt sensing coil is in parallel with generator field Carbon pile voltage regulator - Air gap is max initially

Any reduction in generator speed produces a reduction in generator output voltage. So, armature moves away from electromagnetic force of voltage coil and carbon pile is compressed.

Load sharing – volatage of lightly loaded generator is to be increased, so it will take more load.

Csdu – Low oil pressure warning 120 to 160 psi High oil temp warning at 157 degree centigrade Ac load shading by ubr and elcu Lamp dark method to close the contacts in ac paralleling

Oxygen

Dilute demand for crew

Autopilot

Trim must be set before autopilot engagement Fail soft means fail passive Yaw damper indication in eadi in conjuction with rate of

turn indicator Accuracy of radio altimeter is 1 ft or 3 percent The incidence of ths can be operated by three methods-

electric actuator motor through switch on control column ,

trim servo actuator of automatic flight control system and manual wheel

Ball nut prevents binding of the jackscrew When the trim system is not in operation, rotation of

jackscrew under the influence of air loads, is prevented by braking system

Autopilot holds the aircraft to an external conditions Duplex , triplex systems for system protection against

malfunction like runaway Adhesive bonding is wetting and setting As mach number increased, boundary airflow thickness

increases Comfortable climb is 500 ft per minute Diodes are placed across cotactor to speed up operation

by reducing back emf Cat 2 rvr is 1000 or 1200 ft ? Engine fire bottle at 600 psi and 15 degree centi Radio marker info on adi When flaps ar lowered, auto trim will decrease the

incidence of ths In capacitive fire detection system, if there is a short to

earth the system will work but not test satisfactorily Solid burning oxygen unit has burn time of 15 minutes Cat 2 rvr limit is 400 meter

Bonding lead to aircraft component must be 0.5 in wide or 26 swg

Oil absorbs landing shocks C band radar 7 cm Spar is fail safe structure Minimum passenger aisle width is 15 inch Synchronizing bus bar allows monitoring and trimming

from the flight deck Chromating on mg alloys For pressure bulkhead sealing , soft rubber is used Velocity of air from cabin ventilation system is 120 feet per

second Mach trim is initiated by autopilot motor Fusible plug on tire for over temp protection Radio coupled approach is localizer first, followed by glide

slope Portable oxygen bottles are fitted with demand regulators In air condition using heater, if overheat then reset can be

done only on the ground Max battery temp on charging before protection circuit

starts is 144 degree fah Air conditioning For flight deck, air required is 10 cubic feet per minute Subcooler is a heat exchanger to superheat the vapour Water trap at the inlet of the turbine

Before distribution, air goes through tcv Cabin temp is little more than ambient air temp Conditioned air is temp and pressure adjusted Temp within the cabin is 18 to 24 Before filling vapour cycle system, apply suction to remove

moisture and air Air flow rate from punkha louver should be of minimum 25

feet per minute In vapour cycle, system heat is removed from charge air by

changing liquid into vapour Cabin climb is shown by double scale Cabin roc is less than ambient roc Cabin altitude is the equivalent height of the aircraft from

the sea level Ambient pressure decreases more quickly than cabin

pressure Flight altitude is set 500 ft more than actual flight altitude

to prevent pressure controller hunting Inward relief vale open at 0.5 psi Inward relief valves are interconnected to allow controlled

pressure during desecent Ata 25 Galley equipments – awn 99 Life jacket inspection iaw manufacturer specifications

Toilet smoke detection must have aural or vedio warning in the cabin

Clean seat belts with warm water and low alkalinity soap Megaphones 9g Fire protection Capacitive – short circuit doesn’t result in false warning Systron donner helium gas, contamination monitor for

dirty contacts Apu fire- aural and red light Toilet fire detection awn 83 Smoke detectors detect 10 percent smoke Weight of fire bottle is fitted on bottle head Co 2 fire ext on all fires in fuselage Fire ext can be identified as being used by weigning Flight control On ground, spoilers deflect to 60 degree When pressure is removed, hydraulically operated flight

control surface droops On fly by wire, stabilizer trim is controlled by sec and elac For auto trim system to operate, autopilot need not tobe

engaged Artificial feel for power operated system Fries ailron increases drag to increase the rate of yaw and

turn Manual reversion should be automatic and instantaneous

Servo vale directs hydraulic fluid to the jack Cg aft, stick force reqd high Tail plane is not a primary control Powered flying control actuators transmit pilot input to

the control surface Spoiler panel should not affect pitch trim If spoilers loss electrical power, then go to zero position Pulleys in flight control system are made of Teflon or al

alloy Interrupter arm in flight control locking mechanism

restricts the movement of throttle Ground spoilers decrease wing loading on landing Outboard ailerons are isolated at high speed to prevent

ailron reversal Fuel system

Fuel tanks interconnected must have protection against overfill

If fadec loses air data, it goes to soft reversion To prevent water condensation, tanks should be filled as

full as possible When jettission valve in transit, magnetic indicator is

amber and cross Before installation, linen bag should be wetted with water

Do not jettison when flaps are in transit Jettison indication – white flash means jettison has been

completed, magneta means fuel to remain after jettison In jettison, all pumps and cross feed valves open Hydraulic power Air is removed from hydraulic by passing through a tray Pressure control relay is de enerzied to start the pump Non return valve directs fluid to hydraulic actuator Acov hammering is due to low accumulator pressure Thermal relief valve senses fluid pressure Phosphate easter requires butyl rubber or Teflon Ice and rain Anti ice fluid is applied at 100 psi and 70 degree centi Windscreen wiper torque test at shaft end De icing pipeline is nylcon Landing gear Oil absorbs shock Flutter plate permits free flow of oil during compression

and restricts the flow during extension Alignment check of mlg = symmetry, camber and track On detachable flange, locking ring Composite brake – increased efficiency at higher temp Yellow fuse plug melts at 200 deg centi Restrictor controls landing gear extension and flap

retraction

Restrictor is fitted in the up line of landing gear, restricting the flow from the actuator

Breaker strip between casing plies and tread rubber Hop damper to Tubed tyres stored horizontally, upto 4 in total and

smallest at top Positive camber – bottom of wheel towards fuselage Torque links keep the wheels in track Red or yellow line in inner tube is heavy spot Light Port red Cargo bay light by ac Runway turn off and taxi light is fifty degree Master dim and test switch to on position – rectangular

indicator lights will illuminate Escape route light no more than twenty percent obscured Rotating beacon 40-45 rev/min and frequency of 80-90

cycles per minute If blow back device operates on landing lamp, it is reset by

selecting full retract Fluorescent tube 115 v ac Self illuminating signs ha phosphor coating and tritium gas Captain’s and first officer’s dome lights are in series Strobe light xenon gas and blue white color Navigation lights from single circuit

Floor proximity lights on 40 inch interval Automatic no smoking sign at below 10000 ft and desend Oxygen Hygrometer to measure moisture Oxygen cylinder dates are painted white on the neck Sodium chlorate and iron mixed by electronic detonator Left hand thread on charging connection Double headed pressure regulator for additional crew Critical altitude for oxygen requirement is 25000 ft In emergency, 100 percent oxygen continuous flow

positive pressure Portable cylinder is alloy steel Oxygen filters sintered bronze Lubrication yellow Oxygen green Hydraulic yellow and blue circle Fuel red and star Charge oxygen bottle in situ with temp / pressure graph High pressure lines are stainless stell Pneumatic When moisture separator is purged, it dumps the moisture

trap If water drain trap is left open for long time, then it will

drain between compressor and prv

If drain plug of water trap is left open for long period, then system would loose pressure from compressor side only

Waste / water Drain masts are heated using low amperage only when

aircraft is on the ground Seal of the valve is replacable without draining the tank Drinking water pipes are wrapped by heated ribbon or

tape Toilet awn 83 Drain masts by ribbon heater Recirculation fan unserviceable, then close toilet until

landing On board maintenance Modern cmc use crt screen Warning signals are generated by warning computers Acm system stores information for long term error analysis With acms quick access recorder, tape can have been used

previously if it is first bulk erased

Target clearance check on near position

Electrical Open phase sensing on neutral point on current

transformer

In ni cad battery when fully charged, electrolyte level incrases

Undervolt condition in ac generation system causes activation of time delay circuit

Two short prongs on ac plug to prevent arcing during plug connection or disconnection

Purpose of diode in gcr is to prevent back flow of current in emf coil

Eddy currents are circulating current Synchronizing bus bar for interconnection between

generator busbars Vibrating contact generator , sensing coil in parallel with

the field Static inverters on kva Generator on kw and kva On engine shut down, generator tripping is initiated by

undervolt and underfrequency prevents gcr being tripped Generator field relay can be reset only on the ground In parallel ac generator, cba must be equal to cba On normal engine shut down, generator breaker is tripped

oly Control relay brings the generator on line Specific gravity by hydrometer If water is added to ni cad battery when not fully charged,

then spewing will occur

Equalization coil in carbon pile modifies the effect of voltage sensing coil

Acid turns litmus paper into red Polarization is that hydrogen bubbles at negative plage Pmg provides initial excitation Insulation is higher when machine is hot Lamp dark method to synchronize the generators If electrolyte level is low at one cell, then top up individual

cell Instrument Rvsm tolerance for aircraft certified after 1997, 200 and

50 ft for instrument error Niddle of resolver is connected to two coils only Torque synchro for angular position In trun and slip indicator, if speed of the rotor is increased,

then it underreads Dg inner gimbal is restricted to plus minus 85 degree Displacement gyro used on gyro horizon One atm is equal to 14.7 psi Mach warning when mcrit is reached Inner gimbal of vertical gyro for roll Heading is angle between true north and longitudinal axis

of the aircraft t Machmeter true airspeed and local sound speed

Leak check on instrument case Rmi is rbi Relative bearing plus heading equal to magnetic bearing to

the station On rmi , angle between compass datum and radio pointer

is relative bearing Vsi metering unit consists of orifice and capillary Autopilot servo brake to actuate off Handmikes are essential on light aircraft t Decca navigation on low frequency Vlf/hyperbolic decca omega loran c Clutch on autothrottle servo for overriding In transponder, pulse frequency is reply signal sent per

second Hyperbolic system is 400 m, cat 2 rvr B rnav indicates bearing and speed upto next waypoint Autopilot receives input form vor and ils Epr and thrust mode are selected on take off in

autothrottle Ins has mercury switch on all gimbals If runway picture moves down, then aircraft must fly down Bearing information on ddrmi is received from vor and adf Line of sight vhf an uhf Vhf is 108 to 136 Call system for captain is high tone chime

Next database is activated on fmc manually on the ground Atc transponder mode c for altitude information Atcrbs is atr radar beacon system Ticas I gives ta and ticas II gives ra When ths in motion, auto trim is inhibited To obtain accurate gps fix, ther must be 4 satellites in line

of sight Dh aural warning at decision height Fmc pin programming for position compensation Before moving from the loading pier, latitude and

longitude of the pier must be entered into the ins Ins detects acceleration down to 10-6 g Fmc receives 24 digital inputs and 3 descrete inputs and 9

digital outputs In strapdown inertial navigation, 3 acceleratometer and 3

gyro and no gimbals Centripetal error compensation by applying additional

signal to n/s acceleratometer Transport rate compensation by platform being torque by

computed torque signal Localizer deviation signal comes from vhf nav system Bearing of ground station is determined by comparing the

phase of two 30 hz modulations Radio areal masts are bonded In vor, referrece and variable singal

Oss over station sensor detects the rapid rate of vor singal over the cone of confusion

Attitude hold an ils incompatible fd modes Side lobe suppression to mute dme during atc transmit L band dme transmits at 1090 mhz Aerials provide optimum output when load is purely

reisitive Torque preset in autopilot to allow override Fmcs utilizes ils , adc , dme Fmcs doesn’t use adf Structure Differential ailron increases drag on inner wing Ailerons control the aircraft in lateral plane Downward displacement of ailron decreases stall angle Flap induced downwash decreases the tailplane incidence Induced drag curve characteristics of slender delta wing is

such that there is decrease in gradient with increase in speed

Root stall on detla wing At speed above mach 1, shock wave at both leading and

trailing edge Symtomps of shock stall are buffet, loss of control and

instability Vortex generators make flying controls more effective at

high speed

Zone 320 is vertical stablzr Bonding lead 50 milliohm and 0.5 in wide Zone 323 is between fron and rear spar and 324 is top of

vertical stablzr Compression loads are taken by stringers Waffle doubler acts as tear stopper Faying surface is material under repair Paint spray tem 15 to 25 and humidity below 75 Synthetic resin consist of nylon, vynil and acrelyc Stowage doors inspection on catches Wall mounted seats are fixed to stanchions Main undercarriage is attached to aircraft structure Direction of travel of ths is determined by solenoid

operated clutch Primary purpose of sealant used in pressurized aircraft is

to prevent corrosion Upper and lower strobe lights are red Semi monoquo offers good damage resistance Subcooler cools the vapor further to prevent slugging Multispar means more than one spar Mid spar assists main spar with operational loads Structure primary is red, secondary is yellow and tertiary is

green

Primary structures are engine mountings, frames, spars, main floor members

Secondary structures are ribs and parts of the skin of the wing , skin and stringers of the fuselage

Landing gear is attached to rear spar Series motor – if load is removed then motor overspeeds

dnageously, it has high starting torque Structural members are designed to carry side and end

loads Gimbal brake restricts outer gimbal Acms supplies cmc with source of fault Synchronization bus bar provide interconnection

generator busbars In vibrating contact regulator, sensing coil is inseries with

field winding Gcr connects field powr supply to generator excitor Vent holes on tubeless tyres only In cmc, warning signals are generated by warning

computer Rising runway appears at 200 ft Main undercarriage is attached to aircraft structure In pressurized cabin there is agauge that shows cabin

differential pressure Fuel scavange system to disperse water Selcal operates on hf or vhf

In international aviation, SELCAL or SelCal is a selective-calling radio system that can alert an aircraft's crew that a ground radio station wishes to communicate with the aircraft. SELCAL uses a ground-based encoder and radio transmitter to broadcast an audio signal that is picked up by a decoder and radio receiver on an aircraft. The use of SELCAL allows an aircraft crew to be notified of incoming communications even when the aircraft's radio has been muted. Thus, crewmembers need not devote their attention to continuous radio listening.

Hirf means high intensity radiated field

Gps use atomic clock

In strapdown ins, solid state acceleratometer

Marker beacon receiver has no control unit

Acars frequency is 131.55 mhz

Microwave landing system frequency is 5ghz

Glideslope indicator niddle is horizontal

Priority order from highest is windshear, gpws and tcas

Vor is 108 to 118

Dme 962 to 1213 mhz

omega 10 to 14 khz

gps is based on principle of satellite ranging – calculating position

hf antenna has weak point as base

in vhf, 25 khz separation and 720 channels

weight of extinguisher is stamped on head fitting

water for class a fire

methyl bromide is most harmfull fire ext agent

laboratory smoke detector for 20 seats or more

tyre creep or slippage

positive camber means bottom of wheel closer to fuselage

dome lights are in series

apparent drift of vertical gyro is a function of sin latitude

with increase in mach number, boundry layer thickness increases

diode across a coil reduces back emf

gcr trip signals are undervolt and differential protection

wavelength of x band is 3 cm

a fire zone in which crew member could enter to fight a fire is class a

spars are front, main and rear

front takes air load and main takes structural laod

oxygen cylinder test dates are stamped on the neck

in vibrating contact, sensing coil in paralle with the field

hydrometer reading doesn’t read temp correction if electronlyte temp is 60 deg f

speed of alternator may be controlled by csdu

insulation resistance is high when machine is hot

ambient air pressure is set on millibar scale

rmi input from vor and azimuth gyro, rmi shows relative bearing

machmeter works on pitot and static

in irs, laser ring gyro

vhf 108-136 mhz

random precession of inner gimbal is detected by mercury switch in inner gimbal

side lobe suppression mutes dme operation during transmission phase

fuse plugs in tyre for over temp protection

if aircraft is aerodynamically stable, then it returns to trimmed attitude

semi monocoque offers good damage resistance

ins pin programming for magnetic orientation

acms airplane condition monitoring system provides source of fault for cmc

field realy can be reset by cycling the generator switch

rising runway appears at 200 ft

cabin climb rate is shown by double scale

drinking water pipes are wrapped with ribbon

ribbon heater on drain mast

fire bottle – all three pins must be shorted together and ground to the cartridge body

a check valve prevents jettison of outboard tanks