Oman CAA ATPL(A) Theory flashcards

42 cards. Read the term and the definition here. The deck at the top of this page is optional.

Semi-circular rule

IFR cruising levels: magnetic tracks 000-179 use odd flight levels, 180-359 use even flight levels; RVSM applies between FL290 and FL410.

MAYDAY vs PAN PAN

MAYDAY is the distress call for grave and imminent danger; PAN PAN is the urgency call for urgent but non-distress situations.

Class A airspace

Airspace where only IFR flights are permitted and all flights receive ATC separation; VFR is not allowed.

VMC minima above 10000 ft

In Class C above 3050 m AMSL, VMC requires 8 km flight visibility and 1500 m horizontal, 300 m vertical distance from cloud.

Compressor surge cause

Excessive angle of attack of compressor blades, often from abrupt throttle changes or disturbed intake airflow, causing flow reversal and bang.

Bleed air source

Pressurisation and anti-ice air is normally tapped from the high-pressure compressor stage; excessive extraction reduces engine thrust margin.

Hydraulic accumulator function

Stores pressurised fluid to damp pressure surges, absorb thermal expansion and supply transient demand during high-load operations.

Pitot heat failure

Blocked or unheated pitot tube produces erroneous airspeed; static blockage affects airspeed, altitude and vertical speed together.

QNH vs QFE

QNH set on the subscale gives altitude above mean sea level; QFE gives height above the aerodrome reference datum.

High-to-low pressure error

Flying from high to low pressure without resetting the altimeter subscale causes the aircraft to be lower than indicated.

Turn coordinator indication

Shows rate of turn and roll attitude; the turn-and-slip indicator shows rate of turn only without roll information.

Magnetic compass errors

Turning and acceleration errors make the compass unreliable in manoeuvres; it is most accurate in straight, level, unaccelerated flight.

CG shift formula

Moving mass m by distance d shifts the CG by (m × d) / total mass; the CG moves toward the added or moved mass.

Maximum zero-fuel mass

Structural limit for the aircraft without usable fuel; take-off mass is MZFM plus fuel and must not exceed MTOM.

Forward CG limit

Set by elevator authority for rotation and landing flare; an excessively forward CG may prevent rotation or flare.

Dry operating mass

Basic empty mass plus crew, crew baggage, catering and unusable fuel; traffic load is added to give zero-fuel mass.

V1 decision speed

Speed at which a take-off must be continued after failure; before V1 a rejected take-off must be possible.

Balanced field length

Field length where accelerate-stop distance equals accelerate-go distance, giving the minimum required runway length.

Density altitude effect

Higher temperature and pressure altitude increase density altitude, reducing engine power, lift and climb performance.

Climb gradient formula

Climb gradient (%) = (height gained / horizontal distance) × 100; 3.3% corresponds to about 200 ft per nautical mile.

Specific range

Distance flown per unit fuel (NM/kg); best specific range occurs near the speed for maximum lift-to-drag ratio.

Equal time point

Point where time to destination equals time back to departure; equal fuel point uses fuel burn instead of time.

Descent rate planning

For a 3-degree path, required rate of descent in ft/min is approximately groundspeed in knots multiplied by five.

Headwind fuel penalty

A headwind increases trip fuel and time; the penalty is greater at lower true airspeed for a given wind component.

Time of useful consciousness

Duration of effective performance after loss of oxygen; falls rapidly with altitude, from minutes at FL350 to seconds at FL500.

Hyperventilation treatment

Reduce breathing rate and depth, reassure the patient; symptoms include dizziness, tingling and anxiety from low CO2.

Vestibular system function

Semicircular canals sense angular acceleration; otoliths sense linear acceleration and gravity; neither detects constant velocity.

Night vision characteristics

Rods provide night vision, are slow to adapt and poor at colour; bright light destroys dark adaptation for many minutes.

ISA sea level values

Sea level temperature 15 °C and pressure 1013.25 hPa; temperature lapse rate 1.98 °C per 1000 ft up to the tropopause.

Cold front characteristics

Steep slope, rapid passage, cumuliform cloud, showers, squalls and good visibility behind the front.

Radiation fog conditions

Forms when temperature reaches dewpoint with clear skies, light wind and high humidity, typically overnight over land.

Great circle vs rhumb line

Great circle is the shortest distance with continuously changing track; rhumb line maintains constant track but is longer.

1-in-60 rule

Distance off track equals track error in degrees divided by 60, multiplied by distance flown; valid for small angles.

VOR radial indication

CDI centred with TO/FROM flag indicates the aircraft is on the selected radial; the radial is the magnetic bearing from the station.

DME slant range

DME measures slant range, which exceeds ground distance at high altitude and close range; error grows near the station.

Transponder emergency codes

7700 for emergency, 7600 for radio failure, 7500 for hijack; Mode C transmits pressure altitude.

Rejected take-off actions

Close throttles, apply maximum braking, maintain directional control and use reverse thrust as available.

Emergency descent procedure

Don oxygen masks, descend at maximum rate to 10000 ft or MSA, notify ATC with MAYDAY and advise intentions.

Minimum fuel declaration

Declare minimum fuel when committed to land at a specific aerodrome and any change causes landing below final reserve.

Lift formula

Lift equals half rho V squared S CL; induced drag equals L squared divided by half rho V squared S pi e AR.

Stall angle of attack

Stall occurs at the critical angle of attack regardless of speed, mass or attitude; load factor increases stall speed by square root of n.

Dihedral effect

Wings set at an upward angle provide lateral stability; a sideslip produces a rolling moment restoring wings level.