Iran CAO ATPL Theory cheat sheet

ICAO Annex 2: VFR flight requires flight visibility ≥ 5 km and distance from cloud ≥ 1500 m horizontally, 300 m vertically (unless otherwise authorised by State).

Semi-circular rule: magnetic tracks 000°–179° use odd flight levels (e.g., FL 090, 110); tracks 180°–359° use even flight levels (e.g., FL 100, 120).

Aircraft on converging paths: the aircraft with the other on its right has right-of-way; head-on both turn right; overtaking aircraft keeps clear (turn right if necessary).

ATC clearance: read back all clearances involving runway, altitude, heading, speed, and frequency; if readback incorrect, ATC must correct.

Emergency frequency 121.5 MHz; distress call MAYDAY (3x), urgency PAN-PAN (3x).

Position reporting: at compulsory reporting points, report aircraft identification, position, time, altitude, next position and ETA.

ICAO Annex 1: Class 1 medical valid for 12 months for single-pilot commercial operations; Class 2 for PPL 24 months (under 40) or 12 months (over 40).

Wake turbulence separation: Heavy behind Heavy – 4 NM; Medium behind Heavy – 5 NM; Light behind Heavy – 6 NM.

Piston engine detonation: uncontrolled explosion after ignition; causes high cylinder head temperature and pressure spikes; remedies: reduce power, enrich mixture, lower CHT.

Turbojet: N1 = low-pressure compressor speed, N2 = high-pressure compressor speed; EGT indicates turbine temperature; EPR = engine pressure ratio.

Electrical: alternator/generator output controlled by voltage regulator; overvoltage relay protects bus; battery provides emergency power.

Hydraulic system: pressure typically 3000 psi; relief valve prevents overpressure; accumulator damps pressure surges and provides limited emergency supply.

Fire detection: engine fire handles close fuel, hydraulic, bleed air, and electrical; extinguishing agent (Halon) discharged into affected zone.

Landing gear: squat switch prevents gear retraction on ground; emergency extension by gravity or nitrogen bottle.

Pitot-static: pitot tube provides dynamic pressure; static ports provide ambient pressure; blockages cause erroneous airspeed and altitude indications.

Oxygen system: continuous-flow for passengers, demand for crew; check pressure before flight; minimum 10% reserve.

Fuel planning: trip fuel + contingency (5% or 3% with en-route alternate) + alternate fuel + final reserve (30 min holding) + taxi fuel.

True airspeed (TAS) = IAS × √(ρ0/ρ) approximately; use flight computer for precise conversion.

Wind triangle: heading = true track ± drift; ground speed = TAS × cos(drift) + wind component.

Point of No Return (PNR): distance = (fuel available × GS out × GS back) / (GS out + GS back).

Equal Time Point (ETP): time to ETP = (total fuel available × GS back) / (GS out + GS back).

Flight plan must be filed at least 30 minutes before departure for IFR; changes require ATC approval.

Monitoring: compare actual fuel consumption with planned; if excessive, recalculate endurance and consider diversion.

Hypoxia: symptoms include euphoria, impaired judgment, cyanosis; time of useful consciousness at FL 350 ≈ 30–60 seconds.

Spatial disorientation: somatogravic illusion (false climb/descent), leans, Coriolis illusion; rely on instruments.

Stress: performance curve (Yerkes-Dodson) – optimum arousal; high stress reduces performance.

Fatigue: circadian rhythm low at 03:00–05:00 and 15:00–17:00; sleep debt impairs alertness.

Vision: foveal (day, colour) vs peripheral (night, motion); dark adaptation takes 30 minutes; avoid bright light.

Hearing: noise-induced hearing loss; use headsets; communication intelligibility affected above 90 dB.

Decompression sickness: nitrogen bubbles; avoid flying after diving (12–24 hours).

ISA: sea level temperature 15°C, pressure 1013.25 hPa, lapse rate 1.98°C/1000 ft (2°C/1000 ft).

QNH: altimeter setting to indicate elevation; QFE: height above reference; QNE: standard 1013.25 hPa for flight levels.

Cloud types: cumulonimbus – thunderstorms, icing, turbulence; stratus – low ceiling; cirrus – high altitude.

Wind: veers with altitude in Northern Hemisphere (backing in Southern); surface friction reduces speed and causes backing.

Icing: clear ice (large supercooled drops, rapid accumulation), rime ice (small drops, rough), mixed; use anti-ice/de-ice.

Thunderstorm life cycle: cumulus, mature (updrafts/downdrafts, lightning, hail), dissipating; avoid by 20 NM.

Jet stream: core wind ≥ 60 kt, near tropopause; CAT associated with wind shear.

Great circle: shortest path between two points; rhumb line: constant track, longer except at equator/meridians.

Mercator projection: rhumb line straight, great circle curved; scale varies with latitude.

Lambert conformal conic: straight great circle approximately; used for polar and mid-latitude charts.

Heading = track ± drift; drift = arcsin((wind speed / TAS) × sin(wind angle to track)).

1 minute of latitude = 1 NM; 1 minute of longitude = 1 NM × cos(latitude).

Magnetic variation: east is least (subtract from true to get magnetic), west is best (add).

Time zones: UTC; local time = UTC ± offset; 15° longitude = 1 hour.

VOR: radial = magnetic bearing from station; CDI centred with TO/FROM; identify by Morse code.

ILS: localizer (108–112 MHz) provides lateral guidance; glideslope (329–335 MHz) provides vertical; marker beacons at OM, MM, IM.

NDB/ADF: relative bearing = angle between aircraft heading and bearing to station; QDM = magnetic bearing to station, QDR = from station.

GPS: 24 satellites, 6 orbital planes; RAIM ensures integrity; accuracy ~5 m.

DME: slant range distance; ground speed and ETA displayed; frequency paired with VOR/ILS.

Transponder: Mode A (squawk), Mode C (altitude); code 7700 emergency, 7600 radio failure, 7500 hijack.

Radar: primary returns from precipitation; secondary uses transponder; ATC separation uses radar.

Takeoff briefing: include V1, VR, V2, emergency actions, terrain, weather, rejected takeoff decision.

Approach briefing: type, minima, missed approach, go-around, runway conditions.

Stabilised approach: by 1000 ft IMC or 500 ft VMC, aircraft must be on correct path, speed, configuration.

Emergency: MAYDAY for distress, PAN-PAN for urgency; use 121.5 MHz; squawk 7700.

Minimum fuel: declare when fuel may lead to landing below final reserve; emergency fuel: priority handling.

De-icing: holdover time tables; check critical surfaces before takeoff.

Crew resource management: assertiveness, situational awareness, communication, workload management.

Lift = ½ ρ V² S CL; CL increases with angle of attack up to critical angle (stall).

Induced drag: decreases with speed, increases with weight; parasite drag increases with square of speed.

Stall: angle of attack exceeds critical angle; speed varies with weight, load factor, altitude.

Load factor: n = 1/cos(bank angle) in level turn; stall speed increases by √n.

Mach number: M = TAS / speed of sound; critical Mach number when local airflow reaches sonic speed.

Swept wing: reduces wave drag, increases stall speed and pitch-up tendency.

Boundary layer: laminar vs turbulent; vortex generators delay separation.

Phonetic alphabet: Alfa, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu.

Readback: runway, altitude, heading, speed, frequency, clearance, QNH.

VFR position report: identification, position, time, altitude, next position, ETA.

IFR clearance: clearance limit, route, altitude, frequency, squawk.

Emergency: MAYDAY (distress), PAN-PAN (urgency); state nature, intentions, position, altitude, fuel.

Radio failure: squawk 7600; continue VFR, land at nearest suitable; IFR follow lost comm procedures.

Standard phraseology: "roger", "wilco", "affirm", "negative", "standby", "say again".

Centre of gravity (CG) limits: forward limit ensures elevator authority; aft limit ensures stability.

Basic empty mass + payload + fuel = takeoff mass; landing mass = takeoff mass – trip fuel.

Moment = mass × arm; CG = total moment / total mass.

Load sheet: dry operating mass, takeoff fuel, takeoff mass, trip fuel, landing mass.

Maximum zero fuel mass (MZFM) limits payload; maximum takeoff mass (MTOM) limits fuel + payload.

Fuel density: 0.72 kg/L (avgas), 0.8 kg/L (jet fuel); temperature affects density.

Balance: forward CG increases stall speed and reduces cruise performance; aft CG reduces stability.

Takeoff distance: increases with altitude, temperature, weight, tailwind, upslope, wet/contaminated runway.

V1: decision speed; VR: rotation speed; V2: takeoff safety speed; VREF: landing reference speed (1.3 VSO).

Landing distance: increases with weight, altitude, temperature, tailwind, downslope, wet runway.

Climb performance: rate of climb = (excess power / weight); decreases with altitude.

Service ceiling: altitude where climb rate = 100 ft/min; absolute ceiling = 0 ft/min.

Engine failure: accelerate-stop distance, accelerate-go distance; balanced field length.

Use performance charts: correct for pressure altitude, temperature, weight, wind, runway slope.

Pitot-static: airspeed indicator (dynamic pressure), altimeter (static pressure), vertical speed indicator (rate of static pressure change).

Altimeter errors: position error, instrument error, temperature error (high temp = altimeter underreads).

Airspeed: IAS, CAS (corrected for position and instrument error), EAS (corrected for compressibility), TAS (corrected for density).

Gyroscopic instruments: attitude indicator (rigidity), heading indicator (rigidity), turn coordinator (precession).

Magnetic compass: deviation due to aircraft magnetic fields; turning and acceleration errors.

Glass cockpit: primary flight display (PFD), navigation display (ND), engine indicating and crew alerting system (EICAS).

Radio altimeter: measures height above terrain using radar; used for approach minima.