ATPL 14 Subject Interview Refresher


Flat rated engine is an engine for which the control system is designed to achieve the same level of thrust (hence the “flat” term), up to a certain OAT, then for higher ambient temperatures, the level of thrust decreases as a function of OAT, normally in a pretty linear fashion. Making it more predictable.

A turbofan engine, sometimes referred to as a fanjet or bypass engine, is a jet engine variant that produces thrust using a combination of jet core efflux and bypass air which has been accelerated by a ducted fan that is driven by the jet core. Jet engine is most efficient on High Altitude at High RPM. Due to low air density, there is minimum frame drag.

Service ceiling is where the rate of climb drops below a prescribed value (100 feet per minute climb).

Absolute ceiling is the height at which the rate of climb drops to zero (also known as coffin corner).

The bypass ratio is the ratio between air drawn through the fan that bypasses the engine core to the mass air flow that passes the core.

Direct injection system = fuel is injected into the combustion chamber. This is distinct from manifold fuel injection systems, which inject fuel into the intake manifold. Increases engine efficiency and specific power output as well as reduces exhaust emissions.

Phases of reciprocating = Induction, Compression, Combustion, Exhaust. Intermittent process Constant volume.

Phases of jet engine = Induction, Compression, Combustion, Exhaust. Constant process and pressure

Thrust reverse works by changing the bypass flow direction. The airflow produced by the fan.

EGT = Exhaust gas temperature is measured at the turbine stage of the engine. Exceeding EGT increases the risk of turbine blade creep.

Hung start is a condition where fuel ignites but the engine won’t accelerate to self-sustaining speed.
Wet start is a condition where fuel is already in the combustion chamber.

Drift down procedure is a maximum thrust/minimum rate of descent after engine failure during climb or cruise when the aircraft can not maintain altitude.

V2 is Take-off safety speed. Speed which gives margin above stall speed in take-off configuration. Not less than 1.2Vs.
Vr must be at least 1.05Vmca.
Aircraft speed categories are defined by Vat, 1.3VS at landing configuration at maximum gross landing weight.

Draw the carburetor (remember venturi, throttle valve), pressure drops, and get colder.


Amps are simply the amount of electricity used by the item. 
Volts are the measure of the force of the electric.

An alternator is mechanically engine-driven and produces electrical power when the engine is running.
The battery has stored electrical power. The battery uses a chemical reaction to provide electrical energy DC.

DC = In direct current, the voltage is always constant, and the electricity flows in a certain direction. 
AC = Voltage periodically changes from positive to negative and from negative to positive, and the direction of the current also periodically changes accordingly. 
DC can store electricity, but it is difficult to convert voltage. AC has less power loss due to high-voltage transmission. No worries about negative/positive.

Hot bus = a bus that is constantly energized with power from any source, i.e. battery or generator, when the rest of the system is “locked out” from the power source.

Setting all electrical components to the same potential is bonding. it protects aircraft against fire.


Stall is a reduction in the lift coefficient generated by a foil as the angle of attack increases. This occurs when the
critical angle of attack of the foil is exceeded.

Dihedral = Wing slopes in a positive (upward) degree about the wing base.
Anhedral = Wing has a negative (downward) slope from the wing base.
Anhedral is more stable.

Static stability is the initial tendency of an airplane, when disturbed, to return to the original position.
Dynamic stability is the overall tendency of an airplane to return to its original position following a series
damped-out oscillations.

Longitudinal stability is pitch stability or stability around the lateral axis of the airplane.
Lateral stability is roll stability or stability around the longitudinal axis.
Directional stability is stability around the vertical or normal axis.

Dutch roll increases with altitude. Yaw and roll motions interact. Lateral stability more than longitudinal stability.
Sweepback wings, High wing, and dihedral increase the tendency to dutch roll.

Vx = Most height gained for the shortest distance. Angle of climb 
Vy = Most height gained for the shortest time. Rate of climb

Vortex generators energize airflow over the wing.

Fwd CG = More stable, higher stall speed due to more drag. Less range.
Aft CG = Unstable, lower stall speed, Less drag, may be impossible to recover from a stall.

Coeffiecent of lift allows us to compare wing lifting capabilities at a given angle of attack.
It does not have any units. Lift coefficient curve with flaps, higher and longer curve
How to increase the coefficient of lift? Increase the angle of attack or wing shape.

Chord line = Imaginary straight line from leading edge to trailing edge.
Angle of attack = is the angle between your chord line and the relative wind.
Angle of incidence = Angle between the aircraft’s longitudinal axis and the chord of the wing.
During takeoff, it reduces your pitch angle and gives better visibility. No effect on lift during flight.
Mean camber line = Line joining the leading and trailing edges of an aerofoil, equidistant from the upper and lower surfaces.
Aspect ratio = The ratio of wing length to average chord.

Drag is maximum at Vmo/Mmo(maximum operating limit)
Drag is minimal when induced and parasite drag is equal.

Parasite drag is from the interference of the airframe with airflow. Increases with speed.
Induced drag is the result of creating lift.

A ratio of L/D indicates airfoil efficiency.
Higher L/D ratios are more efficient. If the aircraft is operated in steady flight at a Lift/Drag maximum ratio, the total drag is at a minimum.
Flaps always decrease the maximum lift-to-drag ratio.

The decrease in the angle of incidence from root to tip is Wing washout. It ensures some aileron effectiveness even in stall

Swept wings delay supersonic flow but stall from the wing tip.
Poor lift qualities and higher stall speed.

Mach tuck is a plane’s tendency to pitch down caused by the center of pressure moving rear during transonic speed.
Mach trim
prevents Mach tuck.
Mach Buffet is the separation of airflow from the flight surfaces because they exceed the speed of sound. This occurs because
a shockwave is formed.

Winglets prevent factors like an induced drag. Winglets are aerodynamic surfaces located at the wingtips, they prevent intermixing airflow from upper and lower surfaces.


Green = Cleared to land.
Flashing green = Return to land.

Red = Give way to other aircraft, keep circling.
Flashing red = Aerodrome unsafe, do not land.

The distance between runway centerline lights is 15m and the color of runway centerline lights is white except the last 900-300m are alternative white and red and the last 300m are red.

The distance between runway edge lights is 60m and the color of runway edge lights is white, except the last 600m/half of the runway are yellow.

Taxiway edge lights are Blue.
Taxiway center lights are Green.

High-speed exit taxiway lights are alternative green and yellow. Two yellow centerline lights (3,2,1. 100m between)

CAT I II III minima = 550m/200ft, 300m/100ft, 200m/<100ft 50m/<50ft 0m/0ft

Balanced field = TODR = ASDR.
TODA = TORA + clearway.
ASDA = TORA + stopway.

The contaminated runway is more than 25% and 3mm of water-compressed snow/ice.

Approach ban = If the weather is not enough and the height of the airplane is above 1000ft or before the outer marker, go around.

Black background and yellow letters is Your position currently.
Yellow background and black letters is Your ”destination”.
Red background and white letters is Runway.


Screen height = Distance from where the brakes are released to the point at which the aircraft reaches a defined height. This defined height is known as screen height. It is usually is 35ft(A)/50ft(B) on a dry runway and if the runway is wet it can reduce down to 15 ft.

1st – Starts when the aircraft reaches screen height(35fts). Climb with V2 until the gear is retracted.

2nd – Starts when gear retracted. Still, fly V2. Climb to flap retraction/acceleration altitude, 400AAL(min). Climb gradient of more than 2.4%.

3rd – Starts from flaps retraction/acceleration altitude or 400AAL(min). Accelerate aircraft to retract flaps. Ends when MCT is set and flaps are retracted. Climb gradient more than 1.2%

4th – Starts when MCT is set and flaps are retracted. Climb gradient more than 1.2%. Climb above 1500AAL where the take-off flight path ends.


FADEC = Full Authority Digital Engine Control controls all aspects of engine performance.

ASI compares dynamic and static pressure (Total – static = dynamic)

VSI = barometric capsule in a sealed case. It relies on air moving in and out of the casting to make readings. Operates without any power.

Altimeter = Measures static air pressure.
The principle of operation is that a compressible, sealed metal canister contains a fixed amount of air. When the external air pressure reduces (as the airplane’s altitude increases), the canister expands.

Compass turning errors
Accelerate North, Decelerate South. = ANDS.
Undershoot North, Overshoot South. = UNOS.


Instruments that use gyroscope

  • Attitude Three freedom, Horizontal spin axis Fast erection (less bottom-heavy, reducing errors during turns and accelerations)
  • Heading Two freedom, vertical spin axis |
  • Turn coordinator. One freedom, vertical axis |

RVSM = Reduced vertical separation minima.
FL290-FL410 separation decreased from 2000ft to 1000ft. More aircraft can fit into airspace and airplanes can fly closer to the optimum altitude.
Air is thinner and altimeters are not so precise at that altitude.

CAS = IAS corrected for instrument and pressure errors.
EAS = CAS corrected for compressibility error.
TAS = EAS corrected for density error.

LSS = 38,94 x neliöjuuri Temp in Kelvin.


1m=3.28ft ∼3.3
1ft=0.30m ∼3
1Nm=6080ft ∼6
1Km=0.53Nm ∼0.5

Percentage calculations; turn numbers around 5% of 75, or 75% of 5

If the radius of the wheel is 25cm, what is the distance covered by 2 wheel rotations? o = 2πr = 3,14m

1.1×1.1 = 1,21

Volume of a cube:1000

Prime numbers, all ODD except 2

What is X?

COS 90 = 0 60 = 0.5
SIN 90 = 1 30 = 0.5TAN 45 = 1

The sum of all the angles in the triangle is 180


TAXI – Prior takeoff, for APU consumption, taxiing, and engine start. Usually, it is a fixed quantity.
TRIP – Takeoff, climb, cruise, descend and land.
CONTINGENCY –  Fuel is carried to account for additional route fuel consumption caused by wind, routing changes, or any restrictions. 5% of the trip or 5min holding consumption. Can be reduced to 3%.
ALTERNATE – Missed approach at the destination, climb to level, approach, and land at alternate.
FINAL RESERVE – fly 30min(jet) at 1500ft holding speed in ISA conditions.

A Take-off alternate is required when the weather isn’t sufficient enough to land at the departure airport.
For two-engine airplanes, such an alternate must be within one hour’s flight time at the one-engine-inoperative cruising speed.

Destination alternate is required if the weather is not VMC while landing/approach, more than one independently usable runway can be used or the aerodrome is isolated. Point of safe return must be calculated and additional fuel must be carried. Two destination alternates are required if destination weather at ETA is below operating minima or if the weather forecast is not available.

ETOPS is an extended twin operation. Engine Turn Or Passenger Swim. Operators can operate aircraft for more than 60 minutes from alternate. Categories vary between 60-180min. A320 is 350Nm.


Rest 12 hours or the length of the previous duty period at home base and 10 hours abroad.

24h = 13h
7days = 60h
14days = 110h
28days = 190h

28days = 100h
Calendar year = 900h


ISA 15deg 1013mbar 1,225kgm3 LSS 661 2deg/1000ft 27hpa/mb 37000ft -56,5deg.

The air in Earth’s atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen.

True altitude = True altitude determines the actual elevation of the aircraft above mean sea level (MSL).
Pressure Altitude = Height above the standard datum plane.
Density altitude = Altitude that is pressure corrected or relative to the measurement of temperature. It allows for the measurement of nonstandard temperature variations. Pressure altitude + (120ft x (OAT-ISA temp) )

Temperature affects true altitude because in cold air the air is more dense and pressure levels are closer to each other so in cold weather you are lower than altimeter reads. vice versa.

QNH is station pressure adjusted down to mean sea level.
QFE is station pressure

Convection =
Subsidence = vajoaminen
Convergence = → ← 
Sublimation = Solid to Vapor
Resublimation = Vapor to Solid

Advection fog = Moist airstream flows over snow-covered ground, wind speed less than 10kts.
Radiation fog = Clear sky, cooling of the land at night by thermal radiation cools the air close to the surface.
Frontal fog = Area ahead of a warm front is subject to prolonged continuous rain and same air mass is pushed ahead of the front. Reduction in visibility is caused by high humidity.
Evaporation fog = Cold air is passed over a warmer moist surface.

Sea smoke, frost smoke, or steam fog is fog that is formed when very cold air moves over warmer water.
Arctic sea smoke is sea smoke forming over small patches of open water in sea ice.

METAR = Meteorological Terminal Air Report

  • CAVOK = Visibility 10km or more, no clouds below 5000ft/MSA
  • TEMPO = less than 1h
  • NOSIG = No significant change in weather for the next 2h.
  • BECMG = Gradual change in conditions over a longer time period.
  • TREND = Significant changes in one or several weather elements. Forecast for 2h
  • CEILING = Lowest broken or overcast cloud layer
  • CLOUD BASE = Lowest visible part of cloud over an airfield
  • FEW=1-2octas,SCT=3-4octas,BKN=5-7octas,OVC=8octas
  • FOG and MIST = How far can you see through 1000m or less, fog.
  • TAF = Aerodrome forecast
  • +RA from NS, +SH from TS, CB
  • SWC= Significant weather chart. Jet streams, tropopause heights, fronts, thunderstorms
  • SIGWX=High level significant weather chart!/NAMCON_Nordic_SWC_User_Guide.pdf
  • PROB 30, probably won’t, PROB40 probably will.
  • SPECI = A selected special aerodrome report, issued when significant changes in weather conditions have been observed

BORAT Bora NE wind, E Europe to NE Italy
VOLKSWAGEN Scirocco S wind, N Africa to Mediterranean/S Europe
FÖÖNI Föhn warm and dry S wind, N side of alps(N Italy) to N
MISTRESS Mistral cold N wind, Centre France to coast

Jet stream = Strong and narrow ribbon of air characterized by vertical and horizontal wind shear.
Jet streams form just below the tropopause.
The minimum speed to be considered as a Jet stream is 60knots.

The most severe turbulence in a polar front jet stream is in the cold side.

Avoid CB clouds 10Nm horizontally if below FL200 and 20Nm if over.

Wind Shear = Rapid change in wind direction horizontally or vertically or wind speed, on short distance.

Microburst = Rapid downdraught from the base of CB, usually about 4km in diameter.

Veering is wind turning clockwise
Backing is wind turning anti-clockwise

Geostrophic wind blow parallel to straight isobars
Gradient wind blow around curved isobars

Unstable Air mass = Ascending parcel of air continues to rise to considerable height

Back to the wind, low pressure is on the left side.

High Pressure Area = Clear skies, hazy weather, poor visibility, inversions

  • The wind is clockwise away from the center, more far from surface.

Low Pressure Area = Low cloud base, precipitation, good visibility, mild temperatures.

  • The wind is anti-clockwise towards the center, closer to the surface.

Cold Front has unstable atmosphere, cumuliform clouds, showers of rainWarm Front has light to moderate precipitation with poor visibility. CB clouds(summer months). Cirriform/stratifrom clouds along with the fog.

Icing will increase stall speed, increase weight and drag. Critical AOA will be decreased(airflow will separate more easily due to the rough surface). The maximum Coefficient of Lift (CLmax) is significantly reduced by the ice.

Anti-icing is to prevent ice formation.
De-icing is equipment designed to remove ice after formation.

Carb ice forms because the pressure drop in the venturi causes the air to “cool,” and draw heat away from the surrounding metal of the carburetor venturi. It’s important to understand that carburetor ice results not from a decrease in airflow through the carburetor, but the change in pressure caused by the restriction in the venturi.


Closest to the sun in January =  Perihelion
Farest from the sun in July = Aphelion

The highest latitude where the sun rises is 66N.

The highest latitude where the sun will be overhead is 23.5N(Cancer)/S(Capricorn).

The length of hours of daylight changes most rapidly Spring Equinox and Autumn Equinox.

Civil twilight is between sunset and 6deg below the horizon.

Maximum dip angle 90deg.
Agonic line = Zero variation.
Alginic line = Zero dip.
Isogonal = Equal magnetic variation.

Lambert chart scale is the constant parallel of latitude.

Distance from the equator to the pole is 5400Nm, the circumference of the earth 21600Nm

Rhumb line is an imaginary line on the earth’s surface cutting all meridians at the same angle.
Great circle is the shortest distance between points A and B.

Almanac time = Local mean time.

Change of longitude 15deg/h.
Change of latitude 1deg/60Nm 1min/1Nm.


ILS works using two radio signals, sent from transmitters at the airport and received and interpreted onboard the aircraft.
One of these, known as the localizer, will guide the aircraft laterally; the other, known as the glideslope, vertically.
Localizer frequencies are 108.10 to 111.95 MHz Horizontal and 329.15 to 335 MHz Vertical.
Localizer modulation frequencies are 90 and 150 Hz.
Localizer must be established 2NM before FAF.
Straight and level 1NM before Localizer captures in parallel operations.
3NM separation on airplanes with the same localizer, 2NM separation on parallel localizers.
45deg maximum intercept angle, 30deg if parallel operations.

QDM = Magnetic bearing to the station.
QDR = Magnetic bearing from the station.
QUJ = True bearing to the station.
QTE = True bearing from the station.

Transition Altitude = From ALT to FL.
Transition Level = From FL to ALT.

MSA = Minimum Sector Altitude lowest altitude which may be used in 25Nm radius, provides 1000ft clearance.
MOCA =  Minimum obstacle clearance altitude.1000ft clearance. 1500/2000ft if mountainous.
MEA = Minimum en-route altitude. Minimum published altitude between two fixes that provide navigational signal coverage. 5nm from the center line on either side.
MORA = Minimum off-route altitude 1000/2000ft(mountain) clearance 10nm from the center line on either side.
GRID MORA = 1000ft/2000ft(+5001ft) clearance. Outlined by longitude and latitude lines.

Line of sight = 1.23 x (neliöjuuri korkeus)


10000ft = All occupants of flight deck.
10000-13000ft = Cabin crew.
+13000ft = 100% of passengers.
10000-13000ft of flying 30min = 10% of passengers.

Oxygen masks required is +10% of passenger seats.