Mauritius DCA CPL Theory cheat sheet

Mauritius CAA administers the Civil Aviation Act; CPL licensing follows ICAO Annex 1 standards adopted nationally.

VFR minima in controlled airspace: 5 km flight visibility and 1500 m horizontal, 300 m (1000 ft) vertical distance from cloud.

VFR flight not permitted above FL195 or at transonic/supersonic speeds without an ATC clearance.

CPL minimum age 18; Class 1 medical; 200 total hours including 100 PIC, 20 cross-country PIC and 10 instrument.

Aircraft must carry documents: certificate of registration, certificate of airworthiness, crew licences, journey log and, where required, radio licence.

Rules of the air: overtaking on the right, head-on both turn right, converging - the aircraft with the other on its right gives way.

Landing priority: aircraft in emergency, then balloon, glider, airship, and aircraft towing or refuelling.

Aircraft must be operated per the certificate of airworthiness, flight manual limitations and any applicable airworthiness directive.

Four-stroke cycle order: induction, compression, combustion, exhaust - two crankshaft revolutions per cycle.

Mixture ratio chemically correct is about 15:1 air-to-fuel by mass; best power is slightly rich of peak EGT.

Detonation is uncontrolled explosive combustion; pre-ignition is ignition before the spark - both raise CHT and can destroy pistons.

Constant-speed propeller: governor controls blade angle to hold selected RPM; oil pressure drives toward fine pitch in most light aircraft.

Electrical: battery supplies start and emergency power; alternator/generator charges in flight; ammeter/loadmeter shows charge or load.

Pitot-static: pitot feeds airspeed only; static feeds altimeter, VSI and airspeed; blockage of static causes airspeed to read high in climb.

Hydraulic and vacuum systems: vacuum typically drives gyros; loss of vacuum invalidates attitude and heading indicators.

Weight and balance: datum, arm, moment; CG must remain within forward and aft limits for all loading configurations.

Density altitude = pressure altitude corrected for temperature; high density altitude reduces power, thrust and lift and increases take-off and landing distances.

Take-off distance scales roughly with weight squared and inversely with density ratio; use the aircraft flight manual charts.

V speeds: Vx best angle (obstacle clearance), Vy best rate (time to altitude), Va manoeuvring (turbulence penetration), Vne never exceed.

Rate of climb = excess power / weight; excess power falls with altitude until service ceiling where climb rate is 100 ft/min.

Fuel planning: trip fuel + reserve + contingency + alternate + final reserve; verify against flight manual consumption at planned power.

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

Mass and balance: sum moments and divide by total mass to find CG; forward CG increases stall speed and reduces elevator authority.

Landing distance increases with weight, temperature, altitude, tailwind and runway slope; add 43% for a dry grass runway where the manual requires.

Hypoxia symptoms: euphoria, impaired judgement, tunnel vision, cyanosis; time of useful consciousness at FL180 is roughly 20–30 minutes.

Hyperventilation mimics hypoxia; treatment is controlled breathing and, if in doubt, supplemental oxygen.

Spatial disorientation: somatogravic illusion in acceleration feels like a climb; rely on instruments, not sensations.

Night vision uses rods (peripheral, slow adaptation, 30 minutes); avoid bright light and smoking, which raises CO and impairs night vision.

Cabin altitude above 10 000 ft requires oxygen for crew; above 8 000 ft for prolonged periods passengers should be considered.

Stress and fatigue degrade decision-making; circadian low points around 0300–0600 local and after long duty periods.

Decompression sickness from nitrogen bubbles after altitude exposure; avoid flying within 24 hours of scuba diving.

Alcohol: no flying within 8 hours of consuming alcohol and blood alcohol below 0.02% (or national limit) - check the national rule.

ISA: sea level 15 °C, 1013.25 hPa, lapse rate 1.98 °C per 1000 ft up to 36 090 ft.

QNH set on the subscale gives altitude above mean sea level; QFE gives height above the aerodrome; QNE (1013.25) gives flight level.

Cloud base estimate: (temperature − dewpoint) × 400 ft per °C for convective cloud.

Stable air gives stratiform cloud and steady precipitation; unstable air gives cumuliform cloud, showers and turbulence.

Icing risk greatest in stratiform cloud between 0 °C and −20 °C with supercooled droplets; carburettor icing possible at 0–30 °C with high humidity.

Wind veers with height in the northern hemisphere; surface friction backs the wind and reduces speed near the ground.

Thunderstorm life cycle: cumulus, mature (hail, lightning, downdraughts, gust front), dissipating - avoid by at least 20 NM.

Mountain waves produce severe turbulence, lenticular cloud and downdraughts on the lee side; expect strong wind shear.

Great circle is the shortest path between two points; rhumb line is a constant track and appears straight on a Mercator chart.

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

True bearing = magnetic bearing + variation (east variation subtracts: variation east, magnetic least).

Compass deviation is aircraft-specific and is applied after variation: magnetic heading ± deviation = compass heading.

Track made good is affected by wind; drift = angle between heading and track, corrected by the wind correction angle.

Time to station by the 90° method: time to station = time to turn 90° / degrees of bearing change × 60.

Fuel flow and ground speed give endurance and range; recalculate at each waypoint using actual wind and consumption.

Dead reckoning uses heading, time and speed; position fixes update the estimate and allow calculation of actual wind.

Before take-off: check fuel quantity and grade, controls free, trim set, doors and harnesses secure, no frost or ice on surfaces.

Emergency descent: reduce power, extend speedbrakes, turn away from traffic, use oxygen if needed and declare MAYDAY.

Engine failure after take-off: maintain control, pitch for best glide, select a landing area, attempt restart only if altitude permits.

Fire in flight: close fuel and mixture, use extinguisher, then plan an immediate landing; electrical fire - switch off the master.

Wake turbulence: avoid by taking off before the preceding aircraft's rotation point and landing after its touchdown point; stay above its flight path.

Wind shear on approach: go-around if airspeed or sink rate deviates; apply full power and do not change configuration until clear.

Passenger briefing must cover seat belts, exits, oxygen and smoking rules; no smoking in the cabin.

Ditching and forced landing: transmit position on 121.5 MHz, squawk 7700, and brief passengers before impact.

Lift = ½ ρ V² S CL; induced drag falls with speed and rises with weight, so total drag is minimum at the speed for best L/D.

Stall occurs at the critical angle of attack (about 15–16°) regardless of speed, weight or bank angle.

Load factor n = 1/cos(bank angle); stall speed increases by √n - at 60° bank the stall speed rises by 41%.

Induced drag coefficient = CL² / (π × aspect ratio × e); high aspect ratio wings reduce induced drag.

Longitudinal stability requires the CG forward of the neutral point; too far forward increases stick force and stall speed.

Adverse yaw from ailerons is countered by rudder; use coordinated controls to avoid a spin entry.

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

Propeller thrust falls with forward speed; constant-speed prop keeps RPM constant by increasing blade angle as speed rises.

Distress call: MAYDAY three times, then callsign, nature of distress, position, altitude, intentions.

Urgency call: PAN PAN three times, used for urgent but not immediately dangerous situations.

Read-back is required for runway, altitude, heading and frequency instructions; include the callsign.

Squawk codes: 7700 general emergency, 7600 radio failure, 7500 unlawful interference.

Radio failure in IMC: maintain last assigned speed and level for the last assigned time, then follow the published lost-communication procedure.

Phonetic alphabet: Alpha, Bravo, Charlie…; numbers are spoken digit by digit with five as FIFE and nine as NINER.

Position report format: callsign, position, time, altitude, next position and ETA.

VFR flight plan and arrival reports are required for flights beyond 10 NM from the aerodrome; close the plan on arrival.

VOR gives magnetic bearing from the station (radial); CDI centres when the OBS is set to the desired radial.

NDB/ADF gives relative bearing; magnetic bearing to station = heading + relative bearing; ADF points to the station.

DME measures slant range in nautical miles; error is greatest at high altitude and close to the station.

ILS: localizer gives lateral guidance (108–112 MHz), glideslope gives vertical (329–335 MHz); marker beacons mark distances.

GPS RAIM predicts integrity; check availability before relying on GPS for the approach.

Transponder Mode C reports pressure altitude; Mode S includes aircraft address and supports TCAS.

Radar: primary returns from skin paint, secondary uses transponder replies; ATC separation uses both.

Instrument approach minima depend on approach category, aircraft speed and available lighting and navigation equipment.