GCAA ATPL Theory flashcards
GCAA ATPL Theory · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- V1 decision speed
- The speed at or before which a rejected take-off can be safely accomplished and after which the take-off must be continued; it must allow stopping within the accelerate-stop distance.
- MZFM
- Maximum Zero Fuel Mass: the maximum mass of the aircraft without usable fuel; it protects the wing root bending moment and limits structural loading.
- QNH versus QFE
- QNH is the pressure reduced to mean sea level, giving altitude above sea level on the altimeter; QFE is the pressure at aerodrome level, giving height above the aerodrome.
- Rate one turn
- A turn of 360 degrees in two minutes, giving a rate of 3 degrees per second; it is the standard rate shown by the turn indicator.
- Critical Mach number
- The free-stream Mach number at which airflow over some part of the airframe first reaches the speed of sound, causing shock waves and Mach buffet onset.
- Transition altitude
- The published altitude above an aerodrome at which the altimeter is changed from QNH to standard pressure 1013.25 hPa for flight at flight levels.
- Squawk 7700
- The transponder code selected to indicate an emergency; it alerts ATC and triggers alarm responses on radar displays.
- Induced drag
- Drag caused by lift generation, proportional to the square of the lift coefficient and inversely proportional to aspect ratio; it decreases as speed increases.
- Great circle
- The shortest path between two points on the surface of a sphere; its direction changes continuously and it plots as a curved line on a Mercator chart.
- Conversion angle
- The angular difference between the great circle track and the rhumb line track between two points; approximately half the change in longitude times the sine of mean latitude.
- VOR radial
- The magnetic bearing from the VOR station to the aircraft, displayed by the course deviation indicator with a TO or FROM flag.
- Glideslope angle
- The vertical guidance angle of an ILS, normally 3 degrees; descent rate in feet per minute equals roughly five times the groundspeed in knots.
- Hypoxia time of useful consciousness
- The period from loss of oxygen supply until the ability to act is lost; roughly 30 to 60 seconds at FL 350 without supplemental oxygen.
- Somatogravic illusion
- A false sensation of pitching up or down caused by linear acceleration or deceleration, often leading pilots to push or pull the controls incorrectly.
- Anti-icing holdover time
- The estimated period during which de-icing or anti-icing fluid remains effective under given precipitation and temperature conditions; it must not be exceeded before take-off.
- Sterile cockpit
- A rule prohibiting non-essential conversation and activity during taxi, take-off, approach and landing, and below 10,000 feet, to maintain concentration.
- Accelerate-stop distance
- The distance required to accelerate to V1, recognise an engine failure and bring the aircraft to a full stop; it must not exceed the accelerate-stop distance available.
- Balanced field length
- The runway length at which the accelerate-stop distance equals the accelerate-go distance to 35 feet, giving the optimal V1 for the field.
- Dry operating weight
- The aircraft empty weight plus crew, crew baggage, catering and other operational items, excluding traffic load and usable fuel.
- CG shift formula
- Moving a mass m by distance d shifts the centre of gravity by (m times d) divided by the total mass of the aircraft.
- Density altitude
- Pressure altitude corrected for non-standard temperature; performance decreases by roughly one percent per 1000 feet increase in density altitude.
- Final reserve fuel
- Fuel required to fly for 30 minutes at holding speed at 1500 feet above the destination aerodrome in ISA conditions, as a minimum after diversion.
- Equal time point
- The point along a route where the time to fly to either of two diversion aerodromes is equal, considering wind at the planned altitude.
- Point of no return
- The point beyond which the fuel remaining is insufficient to return to the departure aerodrome, so the flight must continue to its destination.
- ISA lapse rate
- The standard temperature decrease of 1.98 degrees Celsius per 1000 feet in the troposphere, from 15 degrees at sea level up to the tropopause.
- Clear ice versus rime ice
- Clear ice forms from large supercooled droplets between 0 and minus 10 Celsius and is heavy; rime forms from small droplets and is rough and milky.
- Load factor in a turn
- In a level turn the load factor is one divided by the cosine of the bank angle; stall speed increases by the square root of the load factor.
- Critical angle of attack
- The angle of attack at which the wing stalls; it is constant regardless of mass, speed or bank angle, though the stall speed varies.
- Pitot static blockage
- A blocked static port causes the airspeed indicator to over-read in a climb and under-read in a descent, while the altimeter and variometer freeze.
- Mercator projection
- A cylindrical chart on which rhumb lines plot as straight lines; scale increases with latitude and great circles appear curved.
- Reverse current relay
- A relay that disconnects a generator from the busbar when current flows from the battery into the generator, preventing damage.
- Halon fire extinguisher
- An extinguishing agent, typically halon 1301, that interrupts the chemical chain reaction of fire without displacing all oxygen; used in engine and cargo bottles.