CARC ATPL Theory cheat sheet

ICAO Annex 2: an aircraft in flight over the high seas follows the Rules of the Air without exception; over national territory, local rules prevail where they differ.

VMC minima at or above 3050 m (10 000 ft) AMSL in Class C–G: 8 km flight visibility, 1500 m horizontally and 300 m (1000 ft) vertically from cloud.

Below 3050 m AMSL in Class C–G: 5 km flight visibility, 1500 m horizontally and 300 m vertically from cloud; Class B requires clearance from all aircraft.

Semi-circular (hemispheric) cruising levels apply at or above 900 m (3000 ft) AMSL: track 000–179 magnetic uses odd thousands, 180–359 uses even thousands (IFR, or VFR where required).

Annex 1 medical validity: Class 1 single-pilot commercial - 12 months under 40, 6 months from 40 to 59, 6 months from 60; Class 2 - 24 months under 40, 12 months from 40.

Annex 13 definitions: accident = fatality/serious injury, substantial damage, or missing aircraft; incident = occurrence affecting safety but not qualifying as an accident.

Annex 12 SAR: distress phases are uncertainty (position not established), alert (position known, no contact), distress (grave and imminent danger).

Chicago Convention Article 5 grants non-scheduled transit and non-traffic stops without prior permission, subject to the right of the state to require notification.

Semi-monocoque structure: skin carries most shear and tension; stringers and frames stabilise the skin and transfer concentrated loads; fail-safe design uses redundant load paths.

Landing gear shock absorption: oleo strut converts kinetic energy to heat; static load equals aircraft weight, so extension on jacks reads higher than weight due to gas pressure.

Hydraulic systems: pressure = force/area; a smaller piston area gives higher pressure for the same force, and flow rate (not pressure) sets actuator speed.

Gas turbine cycle: compression, combustion at near-constant pressure, expansion; thrust = mass flow × (jet velocity − flight velocity) plus pressure thrust.

Piston engine: mixture control sets fuel/air ratio; best power ≈ 1:12, best economy ≈ 1:16; detonation is uncontrolled explosion after ignition, pre-ignition is ignition before the spark.

Turboprop: constant-speed propeller with propeller governor; beta range controls blade angle on the ground, reverse pitch provides braking thrust.

Electrical: batteries supply DC for starting and emergency; generators/alternators are rated in kVA and protected by overvoltage and reverse-current relays.

Pressurisation: cabin altitude and differential pressure are limited by safety valves; outflow valve modulates cabin pressure, inflow is set by engine bleed.

Density altitude = pressure altitude + 120 × (OAT − ISA temperature in °C); performance tables are referenced to pressure altitude and temperature.

Take-off distance: TODA = TORA + clearway; ASDA = TORA + stopway; TORA is declared take-off run available, not necessarily full runway length.

Climb gradient (%) = (height gained / horizontal distance) × 100; required gradient for obstacle clearance is converted to feet per nautical mile using 6076 ft/nm.

Fuel planning: trip fuel + taxi + contingency (typically 5% of trip) + alternate + final reserve (30 min holding at 1500 ft for turbine) + additional.

Crosswind component = wind speed × sin(angle between wind and runway); headwind component = wind speed × cos(angle).

Load sheet: mass and balance uses arm (distance from datum) and moment (mass × arm); CG = total moment / total mass, and CG must lie within forward and aft limits.

Landing distance available (LDA) may be shorter than TORA when a displaced threshold exists; the displaced portion is usable for take-off but not for landing.

Accelerate-stop distance must not exceed ASDA; balanced field length occurs when accelerate-stop distance equals take-off distance to 35 ft.

Hypoxia: symptoms begin near 10 000 ft cabin altitude; time of useful consciousness at FL350 is roughly 30–60 s, at FL400 roughly 15–20 s.

Hyperventilation causes hypocapnia and cerebral vasoconstriction; treatment is controlled breathing, and it can mimic hypoxia, so 100% oxygen is given first.

Spatial disorientation: somatogyral illusion from sustained rotation, somatogravic illusion from linear acceleration; trust instruments over sensations.

Night vision: rods are most sensitive at about 20° off-centre (dark spot of the fovea), adapt over 30–45 min, and are destroyed by bright light and smoking.

Cabin decompression: at FL400 the time of useful consciousness with rapid decompression is about 15–20 s, so oxygen masks must be donned immediately.

Circadian rhythm: body temperature minimum around 04:00–06:00 local, a window of lowest alertness; window of circadian low is a factor in fatigue risk.

G tolerance: anti-G suit and the AGSM (straining manoeuvre) raise tolerance; G-LOC occurs when cerebral perfusion falls below about 20% of normal.

Error models: slips and lapses are skill-based errors; mistakes are rule- or knowledge-based; violations are intentional deviations from procedures.

ISA: sea level 15 °C, 1013.25 hPa, lapse rate 1.98 °C per 1000 ft up to 11 km (tropopause), then isothermal to 20 km.

Pressure altitude = indicated altitude corrected for subscale setting; true altitude = pressure altitude corrected for temperature, higher than indicated in cold air.

QNH is pressure reduced to sea level; QFE is pressure at the aerodrome; QNE is 1013.25 hPa used above the transition altitude.

Standard atmosphere cloud base estimate: base (ft) = 400 × (temperature − dewpoint in °C) for convective cloud.

Wind: geostrophic wind flows parallel to isobars, and surface friction causes it to cross isobars at about 30° over land, 10° over sea.

Cold front passage: rapid pressure rise, wind veer, temperature drop, squall lines and cumulonimbus; warm front gives gradual lowering cloud and steady rain.

Icing: most severe in the 0 to −20 °C range with supercooled water; freezing rain indicates a warm layer aloft, a serious hazard for airframe icing.

Thunderstorm life cycle: cumulus (updrafts), mature (both updrafts and downdrafts, hail, lightning), dissipating (downdrafts dominate); avoid the mature stage.

Great circle: shortest track between two points, and the initial great-circle track differs from the final track; rhumb line is a constant-track line.

Mercator chart: rhumb lines are straight but great circles are curved; scale increases with latitude, so it is unsuitable for polar navigation.

Lambert conformal conic: great circles are approximately straight; used for many aeronautical charts, with standard parallels and constant scale along them.

Heading = track − wind correction angle; drift = angle between heading and track, and wind correction angle = −drift.

Wind triangle: ground speed = true airspeed × cos(drift) ± wind component; use the CRP-5 or E6B for vector solution.

VOR: radials are magnetic bearings from the station; a CDI with TO/FROM indication shows the selected radial, and reverse sensing occurs when the wrong OBS is set.

ILS: localiser gives lateral guidance on the runway centreline; glide path is typically 3°; decision altitude is referenced to the barometric altimeter.

GNSS: RAIM detects and excludes faulty satellites; with RAIM unavailable, non-precision approaches may not be conducted without other means.

Take-off minima: lowest RVR/visibility depends on approach lighting and runway markings; a full approach lighting system allows lower minima than a basic one.

Stabilised approach: by 1000 ft IMC (500 ft VMC) the aircraft must be on track, at approach speed, and with the landing checklist complete.

Missed approach: apply go-around thrust, pitch for climb, retract drag devices, and follow the published missed-approach procedure; do not turn before the MAPt unless specified.

Emergency descent: oxygen masks on, seat belts fastened, descend at VMO/MMO or the published limit, and broadcast a distress call.

Fire: engine fire uses the fire bottle and shutdown checklist; cabin fire uses halon extinguisher, and smoke removal requires the smoke evacuation procedure.

Take-off alternate is required when weather at destination is below landing minima; the alternate must be within one hour (twin-engine) at one-engine-inoperative speed.

Runway incursion prevention: complete readback of hold-short and take-off clearances; stop at the holding point until explicit clearance is received.

Fuel: minimum final reserve is 30 minutes holding at 1500 ft above the alternate for turbine aircraft; declare an emergency when fuel is below final reserve.

Lift = ½ ρ V² S CL; induced drag = ½ ρ V² S CDi, and induced drag decreases with increasing speed while parasite drag increases.

Total drag is minimum at the speed where induced drag equals parasite drag, which corresponds to best glide ratio (L/D max).

Stall occurs at the critical angle of attack, independent of speed, weight, or bank; stall speed increases with weight and with load factor (Vs × √n).

Load factor n = 1/cos(bank angle) in a level turn; at 60° bank n = 2, and stall speed increases by √2.

Mach effects: critical Mach number is where local flow first reaches Mach 1; above it, shock waves cause drag rise and buffet.

Sweepback raises critical Mach number and improves high-speed performance but reduces low-speed lift and can cause pitch-up at the stall.

Static stability: positive static stability tends to return to equilibrium; positive dynamic stability means oscillations decrease over time.

Flap extension increases CL max and drag; a forward CG increases longitudinal stability but increases stall speed and reduces elevator authority.

Distress call: MAYDAY, said three times, followed by callsign, position, nature of distress, and intentions; urgency call is PAN PAN.

Readback is required for clearances, runway assignments, hold-short instructions, altimeter settings, and frequency changes.

Emergency frequency is 121.5 MHz; VHF distress frequency is 121.5 MHz, and 243.0 MHz is the military UHF equivalent.

Phonetic alphabet: Alpha, 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.

Transponder codes: 7700 emergency, 7600 radio failure, 7500 unlawful interference; squawk assigned by ATC otherwise.

Radio failure in IMC: squawk 7600, maintain last assigned level for 7 minutes, then follow the published lost-communication procedure.

Position report format: callsign, position and time, altitude, next position and ETA, and any other relevant information.

Clearance readback: prefix callsign, repeat the clearance in full, and read back the altimeter setting and assigned frequency.