Mauritius DCA PPL Theory key terms

A mandatory instruction issued by the state of design and adopted by the Mauritian civil aviation authority requiring inspection, modification or repair of an aircraft or component to restore an acceptable level of safety.

A document confirming that an individual aircraft conforms to its approved type design and is considered safe to fly within the limits and conditions specified on the certificate.

The official record linking a specific aircraft to the state in which it is registered, showing nationality and registration marks and identifying the legal owner or operator.

An accident in which an airworthy aircraft, under pilot control, is flown unintentionally into terrain, water or an obstacle, usually because the crew lost situational awareness of proximity to the ground.

The pilot's continuous perception of what is happening in and around the aircraft, comprehension of what it means, and projection of how the situation will develop in the near future.

A condition in which the body's tissues receive insufficient oxygen, producing symptoms such as euphoria, poor judgement, headache and cyanosis; it can develop insidiously above 10,000 feet without supplemental oxygen.

Abnormally rapid or deep breathing that washes out carbon dioxide from the blood, causing dizziness, tingling and cramps that can mimic hypoxia and impair a pilot's ability to fly.

The period after loss of oxygen supply during which a person can still take corrective action before becoming incapacitated, roughly 15 to 30 seconds at 35,000 feet and longer at lower altitudes.

A pilot's mistaken perception of the aircraft's position or motion relative to the earth, typically caused by conflicting vestibular and visual cues in low-visibility conditions without reference to instruments.

The inner-ear organs, including the semicircular canals and otoliths, that sense angular and linear acceleration; they cannot distinguish sustained turns from straight flight and contribute to spatial disorientation.

A planned, brief period of sleep taken by a pilot on the ground or in a suitable crew rest facility to reduce fatigue before a duty period, distinct from uncontrolled napping in the cockpit.

A systematic approach by operators and pilots to identify, assess and mitigate the effects of fatigue through duty limits, rest planning, nutrition, hydration and recognition of personal fatigue symptoms.

The deliberate prioritisation of tasks and use of resources such as checklists, automation and crew coordination so that the demands of a flight phase stay within the pilot's capacity.

The angle between the wing's chord line and the relative airflow; lift increases with angle of attack until the critical angle is reached, beyond which the wing stalls.

The angle of attack at which airflow separates from the upper wing surface and lift reaches its maximum; exceeding it causes a stall regardless of airspeed, altitude or bank angle.

Drag created as a by-product of lift by the spanwise flow and wingtip vortices; it increases with angle of attack and decreases with higher airspeed, being greatest at low speed.

The ratio of total lift to the aircraft's weight, expressed in g; it increases in turns and manoeuvres and raises the stall speed, since the wing must produce more lift.

An aural or tactile device, such as a horn or stick shaker, that alerts the pilot as the wing approaches the critical angle of attack, giving time to reduce AoA before the stall.

The point at which the aircraft's total weight is considered to act; its position must remain within a forward and aft limit for controllability, performance and stability throughout the flight.

The calculation of the aircraft's total mass and the position of its centre of gravity, ensuring both stay within certified limits for the planned flight, including fuel and payload changes.

Pressure altitude corrected for non-standard temperature; high density altitude reduces engine power, propeller thrust and lift, lengthening take-off runs and reducing climb performance.

The altitude indicated when the altimeter subscale is set to 1013.25 hPa; it is the reference used for flight levels and for performance calculations independent of local pressure.

A graph or table in the aircraft flight manual used to determine take-off distance, climb rate, landing distance or fuel consumption for given mass, altitude, temperature and wind conditions.

The pressure value dialled into the altimeter subscale, either the local QNH for altitude above mean sea level or the standard 1013.25 hPa for flight levels.

The altitude, published for each aerodrome or area, at which a climbing aircraft changes its altimeter reference from local QNH to standard pressure and begins reporting flight levels.

The lowest flight level available for use above the transition altitude, ensuring at least the required vertical separation between aircraft at the transition altitude and those at the transition level.

The convention that aircraft flying magnetic tracks from 000 to 179 degrees use odd flight levels and those from 180 to 359 degrees use even flight levels, providing lateral separation between opposite-direction traffic.

A surface of constant atmospheric pressure related to the datum 1013.25 hPa, expressed in hundreds of feet, used above the transition altitude to keep aircraft on a common pressure reference.

Rules under which a pilot operates by visual reference to the ground, maintaining specified flight visibility and cloud separation, and remaining clear of cloud unless a special clearance is issued.

An authorisation allowing a VFR flight to operate within a control zone in conditions below the normal VMC minima, subject to ATC clearance and specified visibility and cloud-clearance conditions.

Rules governing flight in which the pilot navigates and maintains separation primarily by reference to instruments, requiring an IFR flight plan, appropriate equipment and, for the pilot, an instrument rating.

The systematic pattern in which a pilot samples the flight instruments, such as attitude, airspeed, altitude and heading, to detect and correct deviations before they become large.

The four-digit octal code set on the aircraft transponder, assigned by ATC or selected from prescribed conspicuity codes, which identifies the aircraft on the controller's radar display.

An airborne radar beacon receiver/transmitter that replies to ground interrogations with an identification code and, in Mode S or C, pressure altitude information for surveillance and collision avoidance.

The pilot's repetition of an ATC clearance or instruction to confirm correct receipt and understanding; safety-critical items such as altitudes, headings and runway clearances must always be read back.

A message from a traffic collision avoidance system or from ATC warning the pilot of nearby aircraft; a TCAS traffic advisory requires visual search and preparation for a possible resolution advisory.

A routine coded observation of actual weather at an aerodrome, reporting wind, visibility, runway visual range, weather phenomena, cloud, temperature, dewpoint and pressure, issued at fixed intervals.

A coded forecast of expected meteorological conditions at an aerodrome over a stated period, including wind, visibility, weather and cloud, with temporary or becoming changes where significant.

The altimeter subscale setting that, when dialled in on the ground at an aerodrome, makes the altimeter indicate the aerodrome elevation above mean sea level; it is used below the transition altitude.

A document issued by a manufacturer recommending inspection, modification or maintenance action on a product; it becomes mandatory only when made so by an airworthiness directive.