Bahrain CAA ATPL Theory flashcards

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

Semi-circular rule

Magnetic tracks 000-179 use odd flight levels; tracks 180-359 use even flight levels. Above FL290 VFR uses 4000 ft intervals.

Class C airspace

IFR separated from IFR and VFR; VFR separated from IFR and receives traffic information about other VFR. VMC minima apply.

Squawk 7700

The transponder code indicating an emergency. It alerts ATC to give priority and is not used for routine identification.

Balanced field length

The runway length where accelerate-stop distance equals accelerate-go distance, with V1 chosen to minimise required field length.

V1

The decision speed: below it a rejected take-off is possible; above it the take-off must continue. It is at least VMCG and at most VR.

Second segment climb gradient

Required climb gradient with one engine inoperative, gear up, take-off flaps: 2.4% for a twin, 2.7% for a three-engine aircraft.

Maximum zero-fuel mass

The maximum mass of the aircraft without usable fuel. It limits structural loads and is a separate limit from MTOM.

Dry operating index

A moment-based index for the aircraft's empty mass and crew, used with load indices on the load sheet to compute final CG.

Blocked pitot tube

With total pressure trapped, the ASI behaves like an altimeter: it indicates increasing speed in a climb and decreasing speed in a descent.

Turn coordinator

A rate gyro instrument displaying rate of turn and roll. It is not an attitude indicator and does not show pitch.

Radio altimeter

Measures height above terrain using frequency modulation. Valid only at low altitude; used for approach callouts and automatic landing.

Hypoxia time of useful consciousness

At FL350 after rapid decompression, useful consciousness lasts about 30-60 seconds. Oxygen must be applied immediately.

Somatogravic illusion

During acceleration, the otolith organs signal a pitch-up sensation. The pilot may incorrectly lower the nose during take-off.

Inverted-U stress curve

Performance improves with moderate stress but degrades at high stress, when attention narrows and error rates rise.

ISA conditions

Sea level temperature 15 °C, pressure 1013.25 hPa, lapse rate 1.98 °C per 1000 ft up to the tropopause at 36 090 ft.

QNH versus QFE

QNH is pressure reduced to sea level and shows elevation on the ground. QFE is pressure at the aerodrome and shows zero on the ground.

Clear ice

Ice formed from large supercooled droplets in stratiform cloud. It spreads over the surface and is difficult to remove.

Great circle

The shortest path between two points on a sphere. Its track changes continuously and it appears curved on a Mercator chart.

Mercator projection

A cylindrical projection where rhumb lines are straight and scale increases with latitude. Great circles appear curved.

1-in-60 rule

A 1° track error over 60 NM gives 1 NM off track. Correction angle equals distance off track times 60 divided by distance flown.

VOR radial

The magnetic bearing from the VOR station. The CDI centres when the selected radial matches the aircraft's position.

DME slant range

Distance measured directly to the station, not along the ground. Error is largest when directly overhead the station.

ILS Category I

An ILS approach with decision height not lower than 200 ft and runway visual range of at least 550 m.

Final reserve fuel

Fuel required to hold for 30 minutes at 1500 ft above the alternate aerodrome, computed at the planned landing mass.

Equal time point

The point where time to continue equals time to return, determined by wind and true airspeed rather than by distance alone.

Critical angle of attack

The angle at which airflow separates and the wing stalls. It is independent of mass, but stall speed rises with mass.

Load factor in a turn

In a level turn, n = 1/cos(bank angle). At 60° bank the load factor is 2, doubling stall speed's square root factor.

Sweepback effect

Increases critical Mach number and lateral stability but lowers lift coefficient and can promote Dutch roll.

Sterile flight deck

No non-essential communication or activity during taxi, take-off, approach, and landing, and below 10 000 ft.

MAYDAY FUEL

The distress call when fuel is below final reserve. ATC gives priority and the aircraft lands at the nearest suitable aerodrome.

VHF line-of-sight range

Approximate range in nautical miles equals 1.23 times the square root of antenna height in feet.

Readback requirement

Clearances for route, altitude, heading, and frequency must be read back. Ambiguous clearances must be clarified, not assumed.