Civil Aviation History?
Paris Convention 1919 – First international scheduled airservice began
Warsaw Convention – Ticket/ Baggage / Liability
Chicago Convention – ICAO was formed. Five freedoms of air described.
Tokyo Convetion –
Montreal Convention – Damages, Lost baggages, Displaced passengers
Organization Members?
IATA – International Air Tansportation Association
Supports airline activity, helps formulate industry
ECAC – Europan Civil Aviation Conference
Its strategic priorities are safety, security and the environment.
JAA – Joint Aviation Authorities
Priorities operations, maintenance, licensing and certification/design standards for all classes of
aircraft.
EASA – Europan Aviation Safety Agency
Priorities operations, maintenance, licencing and certification
Euro Control –
Coordinates and plans airtraffic control. Controller training, Control of airspace, procedures.
What are the forces acting on an aircraft in flight?
Drag, Thrust, Lift and Weight.
When thrust and drag are in balance, aircraft will maintain a steady speed. For an accelarate thrust
must exceed the value of drag.
When the lift and weight are in balance, aircraft will maintain a steady level attitude. For a climb lift
must exceed the weight.
In a banked turn weight is constant but lift is lost due to the reduction in wing span so lift should be
restored by increasing speed or angle of attack to maintain levelled flight.
Winglet Function?
Winglets are aerodynamically efficent surfaces located on the wing tips. As it is known the high
pressure air below the wings try to escape upper surface. This flow creates wing tip vortices which
produces induced drag. Winglets at the tip of the wings lessen this induced drag and increase the
efficiency of wing.
Lift?
Lift is the force generetad by the pressure difference between the upper and lower surfaces of the
wing and this pressure difference can be explained by Bernoulli’s principle. The air facing aerofil
seperates two parts and the air over the wing travel faster than air o n the bottom. As it is known
faster air produces less pressure.
L= ½ x Coefficent lift x density x surface x Velocity2
High Lift Devices?
High lift devices are moving parts which is used to increase lift.
Trailing edge flaps; There are 5 types of flaps to use extending trailing edge of the wing
Plain, Split, Slotted, Fowler, Slotted Fowler flap
Leading edge flaps; There are 4 types of flaps to use extending leading edge of the wing.
Fixed slot, Moveable slot, Leading edge flaps, Leading dge cuffs.
What is drag?
Drag is the resistance to motion of an object through the air.
It includes various components as profile drag and induced drag. Profile drag is increases directly
with the speed but induced drag indirectly relatedwith the speed.
VIMD= Minimum drag speed. Also it represent best lift / drag ratio that will provide maximum
endurance.
High drag devices?
Flaps, Spoilers, Landing gear, Reverse thrust, Braking parachute
Stall ?
Stall is occured when the critical angle of attack exceeded. After this point the airflow over the upper
surface of aerofil begins to seperate therefore lift production is decreased dramatically.
Stall speed fefcted by various factors;
Weight
Cg
Confugration
Wing design
Density
Icing condition
Turbulent air
Effect of weight on aircraft performance?
Higher take off speed
Longer take off run
Reduced take of climb and angle
Lower maximum altitude
Lower cruise speed
Shorter range
More drag
Reduced maneuverability
Higher stalling speed
Higher landing speed
Longer landing roll
Dutch roll?
Dutch roll is lateral and directional oscilation of aircraft. Especially high speed swept wi ng aircrafts
are suspectible to dutch roll due to smaller fin and rudder area.
Yaw dampers prevent dutch roll. The recovery technique is to apply using opposite aileron if yaw
dampers are not working.
What are the primary flight controls?
Elevator: Control the motion around lateral axis. (Pitch). It is a control surface located at the rear of
the aircraft. If you pull control column back elevator surface will be upward position which produces
aerodynamic force downward for tail of aircraft that pitches aircraft up.
Ailerons: Control the motion around longitudional axis. (Roll) They are control surfaces located at the
wings. If you make control column left, left aileron will be raised which reduces lift of the wing. And
Opposite aileron will be lowered which increases lift of the wing. They are generally operated
hydraulically in heavy and fast aircrafts because of the heavy forces on the contol surfaces.
Rudder: Control the motion around vertical axis. Yaw. It is a control surface located rear of the fin
and controlled by the rudder pedals. If you move left rudder pedal control surface will deflect to the
left which produces aerodynamic force causing a left turn.
Adwerse Yaw?
Adverse yaw is a yawing motion to the opposite direction of turning. It is caused by the drag on the
downgoing aileron which is producing more drag than upgoing aileron.
Adwerse yaw is corrected in the design by the use of differential ailerons.
What are spoilers and how do they work?
Spoilers are opening panels which is located of the upper surface of the wing and have the effect of
producing drag and reducing lift.
Roll Control: Actually spoilers are more efficent even ailerons but they cause too much lost of lift.
(Differential Spoilers)
Air Speed Brakes: Symetrically raised spoilers produce too much drag which is slow down the aircraft.
(Nondifferential Spoiler)
Ground Lift Dumpers: Symetrically raised spoilers produce too much drag whish is decreases lift over
the wing.
What are the effects os extending flaps in flight?
Increase lift by increased wing area and chamber.
Increased drag
Decrease pitch angle
Reduce stall speed
Critical Engine?
The critical engine of a multi engine aircraft is the one whose failure has the worst adverse effects
on aircrats handling performance.
4 engine, clock wise rotating propeller- Left outer engine
2 engine, anticlockwise propeller – Right engine
In crosswind conditions critical engine is the wind side one.
Types of turbine engines?
There are four types of turbine engines.
Turbofan - Turbojet so similar, only difference is that turbofan engine has additional fan to seperate
by pass air to provide engie cooling, less noise and fuel efficiency.
Turboshaft – Turboprop so similar. Only difference is that turboshaft engine drives a shaft that is
connected to a gearbox while turboprop engine drives propeller.
Five Sections of combustion; Induction, compression, combustion, expension, exhaust.
Describe how jet engine works?
There is a divergent entry and convergent exit. (or convergent divergent)
When forward motion is provided from an external source, air is forced into the engine intake where
it loses velocity and gain pressure energy as it passes through divergent duct. The total energy then
increased by the combustion of fuel and expending gasses accelerate to atmosphere.
A jet engine was incapable to produce thrust at low speeds
Gas turbine engines has avoided the weakness of the jet engine by introducing a turbine driven
compressor that produces thrust even at low airspeeds. The pressure energy inreased first by a
compressor than addition of heat energy in the combustion chamber. The airflow finally exhausted
through exhaust nozzle duct.
What is by pass ratio?
By pass ratio is the ratio of the total airmass flow through the fan stage to the airmass flow that
passes through engine core. By pass is used to mix the hot and cld air flow as combined exhaust gas
and it is improves propulsive efficiency, specific fuel consumption, engine noise.
Advantages of fan engine?
Smaller engine size
Better propulsive efficiency
Better specific fuel consumption
Reduced engine noise
Contamination is centrifugally discharged to the by pass duct and it protects the main engine core
from damagres.
What is a reduced / variable take off?
The reduced take off thrust is the correct thrust setting for the aircrafts actual weight that will be
enough for performance requirements even in one engine inoperative conditions.
A higher temperature relates to lower density delivered to engine. The fuel flow is reduced to
maintain correct air/mixture ratio. This produces a lower theoritical thrust from the engines.
There are two reasons for using reduced thrust take off;
To protect enginelife
To reduce noise produced by aircrafts engines.
The limitations of using a reduced take-off are;
Take off field lenght
Engineout climb gradient
Maximum outside air temperature
Contaminated runways
Inop. reverse thrust
Inop antiskid system
Is there a critical engine on a jet/gas turbine aircraft?
There is no critical gas turbine engine because the engines are positioned symmetrically with
opposing revolution direction. But if there is a crosswind conditions we can say that the engine at the
windside is critical engine.
Describe the main differences between jet and propeller engines?
Momentum; Jet aircrafts produce greater momentum
Speed stability; The jet aircrafts has poor speed stability
Wing lift values; Jet engines swept wings produces less lift and high sink rate
Engine response rate to acceleration; The jet engine has poorer acceleration response known as the
lag.
Slipstream effects; the propeller produces extra lift
Stall speed; Propeller aircrafts has lower stall speeds because slipstream effect.
Airspeed Indicator?
ASI measures dynamic pressure as the difference between total pitot pressure and static pressure.
Total pitot pressure (Capsule)
Static pressure (Case)
Static line blockage; Constant – ASI Correctly
Descent – ASI Overrads
Climb – ASI Underreads
Pitot line blockage; Constant – Will not change
Descent – ASI Underreads
Climb – ASI Overreads
In case of blockage;
Ensure that pitot statics probe anti-ice heating on
Use an alternative if aplicable
Fly at correct altitude and power settings
How does an pressure altimeter works?
A pressure altimeter designed to measure the static air pressure. As the aircraft ascends, the static
pressure in the instrument case decreases and allows the enclosed capsule to expand. For a descent
opposite function applies.
QNH - Local altimeter setting (Aircrafts altitude above mean sea level)
QFE – Height (On the airfield elevation it gives zero)
QNE – Standart setting will give the pressure altitude or flight level
Describe NDB / ADF system ?
A non directional beacon send outs a signal in all directions for aircraft.
The ADF is the needle indicator located on the aircraft that shows the direction to the selected NDB
from the aircraft.
NDB/ADF system is used for route tracking, holds, aproach and landing procedures.
The range of NDB controlled by its power and land forms but theoretical range is 300milses over land
and 600 miles over the sea.
The errors of NDB;
Interference from other NDB stations
Thunderstorms
Night Effect
Coastal Effect
Mountain Effect
Quadrantal Error
What is VOR system?
A VHF Omni Range is a short range and accurate navigational aid. VOR sends out line of sight signals
in all directions. And every signal in different direction is differs slightly from its neighbor. These
different direction signals can be tought as tracks.
The range of VOR = 1.25* kök H1 + 1.25 * kök H2
The errors of VOR;
Equipment Errors (max 5 degree)
Site Error
Describe ans ILS system?
The instrument landing system is a precission approach system that gives track and slope guidance
and it has two different ground transmitter.
Localizer; provides tracking guidance to the runway centerline. Signal is protected approximately
6000ft, 25NM, 35 degrees.
Glide Slope; provides vertical guidance to the runway touchdown point. It is normally set an angle 3
degrees. Signals is protected approximately 10 miles 16 degrees.
Describe the DME system?
Distance measure equipment is a secondary radar that gives continious distance readout. Most
DMEs paired with VOR or Localizer frequencies.
Fly by wire Technology?
Fly by wire technology converts the inputs of pilot into electric signals and trasmit to actuators
attached to the control surfaces by wires. This system helps designers to reduce aircrafts weight and
increase reliability.
Etops?
Extented twin engine operations. According to ICAO standarts, a twin engine aircraft operator shall
plan it’s route to land an aeredrome within 60 minutes in case of engine failure. However ETOPS can
increase this time limitations to 180 minutesor more.
CFIT?
Controlled flight into terrain, describes an accident in which an aircraft under pilot control is
unintentionally flown into the ground, mountain, water or obstacle. Main reasons of CFIT are fatigue,
loss of situational awareness, disorientation, misunderstanding charts or ATC clerances . To reduce
the risk of CFIT using GPWS and obeying ICAO rules are important.
GPWS?
Ground Proximity Warning System is a system that designed to alert pilot if an aircraft is in danger of
flying into ground or an obstacle. System monitors aircrafts height above ground and a computer
calculates trends and will warn visual and aural messages If there is a
Excessive barometric rate of descent
Excessive terrain closure rate
Height loss after take off
Flaps or gear not selected for landing
Too low on the ILS glide slope
Descending below approach minima
What is MSA ?
Minimum sector altitude published on ;
Instrument aproach charts at least 1000ft vertical clerance within 25 miles to homing facility
Enroute charts These show gid moras.
What is MEA ?
Minimum enroute altitude is the safe altitude for airway. 5 nautical miles eitherside and radio
reception is guaranteed.
Autopilot?
An autopilot system is an integrated flight control system that enables an aircraft to fly a specified
route and to land at a designated airport. Thanks to autopilot system pilots spend less energy during
flight and do their best at critical phases of flight.
What airsystems use hydraulic power?
Landing gear
Brakes
Steering
Flight Controls
Doors
TCAS?
A traffic collision avoidance system is an aircraft system based on secondary surveillance radar. This
equipment provide advice to the pilot on potential converging aircrafts and protect from collision
accidents.
It is mandated by the ICAO to be fitted with TCAS to all aircrafts with a Maximum take of mass ovr
5700kg or authorized to carry more than 19 passengers.
TCAS 1: TA - only to range about 40 miles
TCAS 2: TA + RA (vertical) traffic information + vertical seperation
TCAS 3: TA + RA (vertical + horizontal) traffic information + vertical and horizontal seperation
Transponder Codes
0000 Mode C malfunction
7700 General Emergency
7600 Radio Failure
7500 Hi-jack
0033 Parachute
7000 VFR when no other code assigned
Mode A: 4 digit code, Mode C : Presure altitude information, Mode S: Callsign, Heading, Altitude
Cabin pressurize system ?
Cabin pressurization system is essential over 10.000 feet to protect crew and passengers from the
physiological problems, such as; hypoxia, altitude sickness and barotrauma which is caused by low air
pressure.
The cabin altitude of a modern aircraft in fly is planned generally 8.000ft.
The most common source for compressed air is bleed air extracted from the compressor stage of a
gas turbine engine and it is regulated by a outflow valve. Compressed air also obtained from auxiliary
power unit on the ground before the main engines started or in case of emergency situations.
What is a Mayday Call?
A mayday call indicates that aircraft threatened by immenant danger and requires immediate
assistance.
Mayday mayday mayday,
ATC
Aircraft callsign
Position
Failures, action being takens and requirements.
What is a Panpan Call?
A panpan call indicates that commender of an aircraft has an urgent message to provide safety of his
aircraft or person on board or another aircraft.
Panpan, Panpan
ATC
Aircraftcallsign
Position
Failures, actions being taken and requirements.
What is the procedure for radio failure?
Contuniue your flight with your current flight plan.
Maintain your last cruising level assigned by ATC
Select 7600
Arrange your flight to arrive over the arrival holding point as close as your last acknowlegded ETA
Start your descent within 10 minutes from over the holding fix at the last acknowledgded the EAT
What dou you know about air datacomputer?
Modern aircrafts feed their static and pitot lines into an Air Data Computer that calculates the TAS,
MACH NUMBER, TOTAL AIR TEMPERATURE, RATE OF DESCENT or CLIMB.
And these calculated datas can be used by;
Autopilot (AP)
Flight Director System (FDS)
Flight Management System (FMS)
Ground Proximity Warning System (GPWS)
Navigation aids
What are the V speeds?
V1 – Engine failure recognotion speed
V2 – Take off safety speed. The aircraft may safely become en airborne with one engine inoperative
V3 – Flap retruction speed.
V4 – Initial climb speed
VA – Design maneuvering speed. ( Full deflection of control surfaces has risk of damage after this
speed.)
Vat – Indicated airspeed at the theresold. (1.3 stall speed)
VB – Design speed for maximum gust intensity
VC – Design cruise speed.
VD – Design diving speed
VF – Design flap speed
VFE – Maximum flap extended speed
VFTO – Final take off speed.
VLE – Maximum landing gear extented speed
VLO – Maximum landing gear operating speed
VLOF – Lift off speed. (The speed which the aeroplane first becomes airborne)
VMC – Minimum control speed ( take off configration)
VMCA – Minimum control speed in the air
VMCG - Minimum control speed in the ground
VMCL – Minimum control speed in landing configration
VMO – Maximum operating speed
VMU – Minimum unstick speed
VNE – Never exceed speed
VNO – Maximum normal operations speed
VREF – Landing referance speed or tresold crossing speed
VS – Stall speed
VS0 – Stall speed landing configration
VSW – Stall warning speed
VX – Best angle of climb speed
VY – Best rate of climb speed
High Speed Flight?
Altough aircraft is flying subsonic, airflow over the wing may rich sonic speeds. When air flow
becomes sonic over any part of aircraft, it results shock wave formation and this speed called as
mach critical. After mach critical, drag rises sharply besides stability and controllability decreases.
To prevent reaching mach critical, at flight level after mid twenties mach number is used.
If an aircraft flies at absolute ceiling, it cannot speed up because of mach critical and it cannot slow
down because of stall speed restriction. This point called as coffin corner.
Sweptwing desing is used to increase aerodynamic performance at high speeds.
Weights?
Aircrafts authorized weight limits are located in the aircraft flight manuals.
Maximum weights established for each aircraft, must not be exceeded during aircraft operation and
loading.
Maximum Taxi or Ramp Weight – MTW or MRW is the maximum weight authorized for taxiing an
aircraft and limited by the aircraft strenght and airworthiness requirements. It is greater than
maximum takeoff weight due to fuel that will be burned during taxi and run-up operations.
Maximum Take-Off or Brake Release Weight – MTOW is the maximum weight authorized for
beggining of the take - off roll and in operations in may be limited by the aircraft performance,
envorimental conditions, airfield characteristics, maximum tire speed and brake energy or obstacle
clerances.
Maximum Landing Weight – MLW is the maximum weight autrized for the normal landing conditions
and in operations it may be limited by the aircraft performance, envorimental conditions, airfield
charecteristichs.
Maximum Zero Fuel Weight – MZFW is the maximum permissable weight without any useable fuel
and limited by the strenght and aiworthiness requirements.
Basic empty mass (empty aircraft + unuseable fuel and oil+ safety eq. + electronical eq.)
Variable load
(crew + crew baggage+ catering loads + lavatory)
----------------------------------------------------------------------------------------------------------+ Dry operating mass
Traffic load
(passengers + baggage + cargo)
Fuel
(useable fuel)
----------------------------------------------------------------------------------- + Useful load
Effects of CG?
Forward CG means more stability, more drug, increased stall speed, increased landing roll,
Aft CG means more controlability, less drug, decreased stall speed, decreased landing roll,
Holding Procedures?
It is used to provide seperation between traffics and to delay due to poor weather or runway
unavailability.
There are two types of holding. Standart holding means right hand turns and nonstandart holding
means left hand turns.
Each circuit of holding starts and ends at over a certain fix. These fixes can be navaid, intersection or
dme distances. These patterns may be done by timing or leg lenght. In timing procedures until
14.000 feets legs should be flown 1 min and over 14.000 feets 1min and 30 secs and always requires
wind correction. In DME procedures there is no need for timing.
Holding speeds should be adjusted according to holding altitude. 230 knots uo to 14.000feet.
There are three methods used to enter a holding pattern. Paralel direct and teardrop entries and the
entry procedure you will apply depends on your heading and outbound course.
Procedure Turn?
Procedure turn is used to reverse course to establish inbound to final approach. There are four type
procedure turns. Racetrack, Teardrop, 45/180, 80/260 degress.
MOCA, MORA, MCA, MRA, MHA, COP, MEA, MAA ?
MOCA – Minimum ostruction clerance altitude. Minimum altitude published on routes which
provides obstacle clerance for the entire route.
MORA – Minimum off route altitude. Minimum altitude published on routes which provides obstacle
clerance 10NM off the route each side by 1000 or 2000 feet in mountainous areas.
Grid MORA - Minimum off route altitude. Minimum altitude published on grid block which provides
obstacle clerance 10NM off the route each side by 1000 or 2000 feet in mountainous areas.
MCA – Minimum crossing altitude. Minimum altitude which has to be gained before reaching that
point.
MRA – Minimum reception altitude. Minimum altitude which ensures reception of navigation signals
to identify this intersection.
MEA – Minimum enroute altitude. Minimum altitude published on the airway which provides signal
coverage and obstacle clerance.
MAA – Maximum authorized altitude. Maximum altitude published on the airway which provides
signal coverage.Above this altitude guiding signal may be confused with another navaid.
COP – Change over point. Point that guiding frequency has to be changed to the next navaid
frequency.
TORA, TODA, TORR, ASDA, EMDA, LDA, LDR,
TORA – Takeoff Run Available is the lenght of runway declared suitable for the ground run of airplane
taking off
TODA – Take off Distance Available TORA + Clearway
ASDA / EMDA – Acceleration Stop Distance TORA + Stopway
LDA – Landing Distance Available is the lenght of runway declerad suitable for the grouınd run of an
airplane landing
TODA = ASDA  Balanced field
RUNWAY ?
Runway thresold – designated space for takeoff and landing under non emergency conditions.
Stopways – Located at the end of runway as emergency space to stop. Marked with yellow
chevrons.
Displaced Thresold – May be used for taxiing, taking off and landing rollout but not for touchdown.
Located at the beggining of the runwaymay be obstacles, noise restrictions.
Runway excursion - an incident involving only a single aircraft, where it makes an inappropriate
exit from the runway.
Runway overrun - a type of excursion where the aircraft is unable to stop before the end of the
runway
Runway incursion - an incident when unauthorized vehicle, person or another aircraft on the
runway
Runway confusion - an aircraft makes use of the wrong runway for landing or takeoff
PAPİ, VASİ ?
Papi – Precision Aproach Path Indicator lights are used for visual precision approach. Four light
system normally located on the left of the runway with a glide angle three degrees. These lights are
visible from 5NM in day and 20NM at night. Two white Two red on the path
Vasi – Visual Aproach Slope Indicator lights are used for visual aproach. Two bar system normally
located on the left of the runway with a glide angle three degrees. These lights are visible from 5NM
in day and 20NM at night. Red over white you are all right.
ALDİS?
Steady Green
Flashing Green
Steady Red
Flashing Red
Flashing White
Alternating R – W
Clear to take off
Clear to taxi
Stop
Vacate Runway
Return to Start Point
Caution
Clear to land
Return and wait for landing signal
Give way to the other aircraft
Do not Land
Caution
What are the main conditions that affect an aircrafts takeoff performance?
Aircraft weight
Aircraft confugration
Aerodrome pressure altitude
Air density
Humidity
Wind
Runway conditions
How is range increased when flying into a headwind?
Headwind never increases your ground range but it is possible to increase your range in headwind
conditions. Higher speed speed allowing less time for the headwind to act. And increase your range.
What are the normal enroute operating performance limitations ?
Obstacle, terrain clerances with one engine inop.
Maximum range limit
ETOPS time limit
Explain a typical fuel plan for a trip?
A Typical fuel profile for flight would include sufficent fuel for the following;
Take off and climb at take off thrust
Climb to the initial altitude with continious thrust
En route cruise
Descent to go around point at destination aerodrome
Contingency fuel %5 of trip fuel or 5 min holding at 1500ft above destination
Diversion to over alternate aerodrome
An additional amount of holding
Precision and Non Precision Aproach ?
Precision approach is an intrument approach using lateral and vertical guidance and as it is
understood from its name it is more precise and has lower minimums than non-precision approach.
Categories of precission approach is limited by the the Decision Altitude (DH) and Runway Visual
Range (RVR) minimums.
CAT I
CAT II
CAT IIIA
CAT IIIB
CAT IIIC
200ft 550m
100ft 350m
50ft 100m
0ft
50m
0ft
0m
An instrument approach may not be continued beyond the DH/DA or MDH/MDA unless the required
visual references for the runway are distinctly visible and identifiable.
Non precision aproach is an instrument approach using lateral guidance but does not vertical
guidance. Non precision approachs use of ground bacons and aircraft equipments such as VOR, NDB
and DME.
A high proportion of CFIT accidents occur during non precision approach as a result of loss of
situational awareness.
Straight in Approach ?
It means that not required nor approved to execute procedure turns. Approach may be initiated
from a fix, DME arc or radar vectors to final.
Straight in Landing ?
When the final approach course is aligned with the runway within 30 degrees, it is called straight in
landing and It means no circle to land maneouvre is required.
Stabilized Approach ?
Stabilized Approach is one of the most critical elements for a safe approach and landing.
An aproach is stabilised when
The aircraft is on the correct flight path
The speed is not lower than VREF or more than VREF 20knots
The aircraft should be in the correct landing configuration
Sink rate is not more than 1000ft
All brieafing and checklists conducted
Top of Descent ?
Top of descent is a point that an aircraft should start descent to reach a point in a designated altitude
with a given vario.
RVSM?
“Reduced vertical seperation minima” airspace reduces the vertical seperation between flight levels
FL290 and FL410 from 2000 to 1000 and makes 6 additional flight levels avaliable for operation. Both
operators and aircrafts should be certified to fly in RVSM airspace and it requires;
2 independent working altimetres
Autopilot
XNDR reporting altitude information
Altitude alert system
Rate of Turn ?
Rate of turn is number of degrees of heading change per time .
As speed increases required bank angle also increase.
1 rate is equal to 3 degrees per second.
Required bank angle for turn 1 rate is equal to TAS/10 + 7
Radius of turn = TAS/ rateofturn*20*pi
Describe the Earths Magnetic Field ?
The earth has a iron core which makes the earth act like a giant magnet with north and south
magnetic poles.The magnetic poles slightly offset from the geographic poles because the obliquity of
the ecliptic.
We call this angular distance between poles as a variation.
Variation east magnetic least
Variation west magnetic best
Turning errors North 20 degree before
South 30 degree after
Turbulance ?
Turbulance is a kind of airflow charecterized by chaotic changes which may cause stress on the
airframe. There are different type of turbulance such as; low level turbulence, clear air turbulance
and mountain wave turbulance.
Low level turbulance may be faced less than 15.000ft and occured because of surface heating,
friction or ground shapes. Wake turbulance also considered as low level turbulance and they are
strenght when the preceeding aircraft slow, heavy, clean configration and high angle of attack.
Light turbulance – Suden changes
Moderate turbulance – Altitude and attitude changes
Severe turbulance – Difficult to control
Extreme turbulance – Impossible to control
CAT ?
Generaly occurs at high altitude with no visual warning. Hard to detect them but usually found in Jet
Streams. 2000ft depth, 10 miles wide, 50 miles long.
Turbulance Penetration?
Maintain level altitude and use penetration speed.
If you encounter turbulance during approach, increase the airspeed slightly above normal approach
speed to attain more positive control.
Thunder Storm Occurence?
Thunder storms are one of the most dangerousweather hazards that pilot should avoid.
Thunderstorms caused by; Instability of air, some type of lifting and high moisture content.
There are three steps of thunderstorm. Cumulus stage, Mature stage and Dissipating stage. There are
several hazards of thunderstorms such as windshear, gust, hail, icing conditions, lightning, turbulance
reduced visibility and radio interference. Pilots shoul avoid them at least 25NM.
Lightning Protection System ?
Lighting strikes generally occurs between the altitudes of 5.000 and 15.000 feets, near of freezing
level and near of thunder storms. Strikes to airplanes are relatively common but rarely result
significant poblems because most aircraft fuselages are made up of aliminium which is a very good
conductor. Also the tickness of the metal surface is sufficent to protect aircraft’s internal spaces from
a lightning strike.
Windshear and Microburst?
Windshear is a sudden change in wind direction, velocity or both wind and velocity at the sametimes.
It can be downward or upward and can cause the significant altitude and speed changes.
Microburst is one of the most dangerous windshear type. It reaches the ground by strong vertical
winds around 6000fpm.
An aircraft can face micoburst especially during aproach or takeoff phases of flight. So if GPWS
alerts the pilot about windshear, only way to recover is to go- around.
Fronts?
A front is defined as the transition between two air masses of different density. There are four types
of fronts which are, cold, warm, ocluded and stationary front.
Warm front; visibility decreases rain or snow occurs and low ceiling will be encountered. Warm
fronts provide advance warning of aproach by devoloping clouds
Cold front; It brings towering cumulus, CB, showers, lightning, thunderstorm, hail, low visibility and
gusty winds. Cold fronts provide little or no warning of approach.
Stationary front; When the forces of two air masses are equal the boundary
Ocluded front; When the fast moving cold air mass catches the slow mowing warm air mass.
Squall Lines ?
It is a narrow band of thunder storms. It devolops on or ahead of cold front in moist and warm
airmass. This line too wide to by-pass and too severe to penetrate. It forms rapidly and reaches its
maximum strength at late afternoon.
Visibility / RVR ?
Meteorological visibility is defined as the greatest horizontal distance can be seen in daylight
conditions for %50 of horizon and published in the METAR. Visibility can be reduced by particles in
the atmosphere such as water, ice, pollution, sand, dust or volcanic ash.
Runway visual range is defined as the horizontal distance a pilot can see on the runway centerline
and it is reported if visibility less than 1500 meters. Also it is one of the main criteria used to
determine ILS category of approach. RV vallues measured at three points along runway. Touchdown
point, midpoint, endpoint
RVR minimum for take off should be 150m if high intensity runway centerline light is available.
Otherwise 200m.
Icıng ?
There are mainly two types of icing occurs on aircrafts.
Induction icing occurs in carburator or air intake of the engine when OAT is between 21 and – 10
(due to fuel vaporization)
Airframe icing occurs when supercooled water freezes on impact with any part of structure when
OAT is between 10 and - 40. Airframe icing can lead; reduced performance, loss of lift, reduced
controlability and loss of controlability.
To avoid icing conditions; Probe heat on when airborne
Crew should monitor air temperature and moisture
Crew should visually check for buildup of ice
Rime Ice; is normally encountered in stratus clouds with a subzero surface. It is formed opaque and
rough and it can affect aerodynamic performance
Clear Ice; is normally encountered in cumulus. It can glaze the the aircraft surface. It is the most
dangerous icing because is has the fastest accumulation.
When you encounter with the icing immediate action is for cumulus change the route and for stratus
change the altitude.
Trace Icing: no need for de-ice / anti-ice operations.
Light ice: de-ice / anti-ice necessary
Moderate ice: de-ice / anti –ice immediately necessary
Severe ice: is beyond the capability of de-ice / anti-ice systems
Anti- ice: Prevents the formation of ice
De-ice : Remove theice after it has been accumulated.
Hydroplanning ?
Hydroplaning may reduce the effectiveness of wheel braking and can cause runway excursions If the
runway surface is contaminated with standing water, slush or wet snow and braking action should be
reported by ATC like “nil, poor, fair, good”.
Pilots are advised to land with possible slower speeds. After nose wheel is lowered moderate
braking should be applied. If deceleration is not enough nose should be raised for aerodynamic drag
to decelerate.
To calculate hydroplaning speed; For take-off : 9 x square root of the tire pressure
For landing:
7,6 x square root of the tire pressure
Inversion ?
When there is an inversion in lapse rate temperature mayincrease with altitude. Radiation cooling
from ground at clear cool nights cause inversions. It usually contributes low visibility, fog, low ceiling,
with no wind and turbulance conditions.
Dew Point ?
Dew Point is the air temperature at which a sample of air would reach 100% humidity. It is the point
which water will condense into liquid. In aviation pilots use dew point data to calculate carburator
icing and visibility.
METAR ?
Is a format for reporting weather information for aviation. And it is used by pilots in preflight
briefings to get redy for the flight. Normally they are generated once in every 30 min but if conditions
change significantly a report as a known speci may be used.
CAVOK – Ceiling and visibility okay; no cloud below 5000, no cumulus at any level, visibility 10km or
more, no significant weather.
Few 1-2 oktas
Scattered 3-4 oktas
Broken 5-7 oktas
Overcast 8 oktas
ISA – International Standart Atmosphere: At sea level
QNH 29.92 inch, 1013mb TEMP 15 Lapse Rate 2 / 100ft density 1225g/m3
BCMG?
It indicates permanent changes in the forcested conditions at some time during specified period.
TEMPO ?
Temporary variation in general forecasted weather lasting less then 1 hour. Once TEMPO event is
finished, the original weather conditions occur again.
TAF ?
Terminal Aerodrome Forecast is a format weather forecast information for aviation. Short taf is
reported every 3 hours for next 9 hours. Long taf published in every 6 hours for next 30 hours.
SIGMET ?
Sigmet is a meteorologic report that adivises significant meteorologic conditions that may affect
flight safety in a general geographic area. Sigmet may include;
Active thunderstorms
Squall lines
Severe turbulance
Severe icing
Marked mountain waves
Sand, dust or volcanic ash
ATIS
The automatic terminal Information service is a prerecorded tape broadcast that gives current
information about aerodrome operations and weather to reduce ATCs workload.
NOTAM ?
NOTAM’s are notices to airmen. Notams are used for to alert aircraft pilots of potential hazards
along a flight route or at a location that could affect the safety of the flight.
Clouds ?
There are four type of clouds; low level, mid level, high level and vertically developed clouds.
Low level clouds from ground to 6500ft AGL and may contain icing hazard. Stratus, Nimbostratus,
Stratocumulus and Fog
Mid level clouds from 6500ft to 20.000ft AGL and may contain severe icing, moderate turbulance.
Altostratus, Altocumulus
High level clouds above 20.000ft AGL. No turbulance no icing. Cirrus, Sirrostratus, Cirrocumulus.
Vertically developed clouds are indipendent of altitude. They show lifting and unstability and may
include all weather hazards; icing, turbulance, lightning, windshear and hail. Cumulinimbus, Towering
Cumulus
Orientation Problems?
Spatial disorientation is a condition that pilots perception of direction does not agree with the reality.
This phenomenon occurs generally in low visibility conditions because witout no referance brain can
not tell realize the difference between gravity and g-load. In this kind situations it is important to
believe instruments.
Vestibular disorientation is a condition caused bymisleading inputs by inner ear. For example a rapid
acceleration can create illision of nose up attitude.
Fatigue, anxiety, lack of sleep, workload, alcohol and drugs increase the possibility of disorientation.
Optical Illusion?
Optical illusions are generally encountered during landing phase of flight. These illusions are
associated with runway width, and runway slope.
Narrow runways lead to an illusion that aircraft is higher so you tend to make a lower approach.
Wider runway causes the opposite.
To overcome optical illusions use glide slope indicator, VASI, PAPI or radio altimeter.
Situational Awareness?
Situational awareness means that having a mental picture of envoirement, other traffics, flight
instruments and intention. For pilots it is very important to have a situational awareness to prevent
incidents and accidents both in the air and on the ground.
IMSAFE Checklist?
Ilness
Medication
Stress
Alcohol
Fatigue
Eat
Atmosphere Layers ?
Troposphere 0 – 36.000
Stratosphere 36.000 – 160.000
Mesosphere 160.000 – 280.000
Thermosphere 280.000
Suplemental O2 Useage?
For pilots over 10.000ft and for passengers over 13.000ft of cabin pressure supplemental O2 useage
is required.
SID?
Standart instrument deperature routes are published flight procedures followed by an aircraft on an
IFR flight plan immediately after take-off.
STAR?
Standart instrument arrivals are published flight procedures followed by an aircraft on an IFR flight
plan just before reaching destination airport.
Wind Gust Corrections ?
½ * stable wind + full gust
for example; 20knots wind 28knots gust
120 + 10 + 8 = 138 correct approach speed
Hypoxia?
Hypoxia is refers to low oxygen conditions and symptoms may change. However the common
symptoms are euphoria, long response time, impaired judgement, limping muscles, dizzy feeling and
headache.
Time of useful consciousness for atmospheric hypoxia
18.000ft 40 min
25.000ft 5 min
30.000ft 2min
35.000ft 1min
40.000ft 20sec
45.000ft 10 sec
Instrument flight Rules position report
Air traffic
Air craft identification
Position and time
Level
Next Position and Estimate