Bahrain CAA ATPL Theory cheat sheet

ICAO Annex 2 (Rules of the Air) applies over the high seas and where no conflicting national rule exists; Bahrain CARs implement ICAO standards nationally.

Semi-circular rule: for magnetic tracks 000-179 use odd flight levels, 180-359 use even flight levels; VFR above FL290 uses 4000 ft intervals.

VMC minima in Class C airspace at/above 10 000 ft: 8 km visibility, 1500 m horizontal and 1000 ft vertical distance from cloud.

Class A: IFR only, all aircraft separated. Class C: IFR separated from IFR and VFR; VFR separated from IFR, receives traffic info about other VFR.

ATIS provides non-control information; the first readback of a clearance must include the ATIS code letter to confirm receipt.

A clearance is an authorisation, not an instruction to act; readback of route, altitude, and frequency elements is mandatory for safety-critical items.

Emergency frequencies: VHF 121.5 MHz, UHF 243.0 MHz; distress call MAYDAY (three times), urgency call PAN-PAN (three times).

Position reporting in oceanic/non-radar airspace uses the standard report: aircraft identification, position, time, altitude, next position and ETA, ensuing significant point.

SSR codes: 7700 emergency, 7600 radio failure, 7500 unlawful interference; these are not to be used for routine identification.

Bleed air for pressurisation and anti-ice is normally taken from the HP compressor stages; engine power loss degrades both cabin pressure control and wing anti-ice capability.

Hydraulic systems are typically duplicated (green/blue or system 1/2/3); a leak isolation valve allows loss of one system without total loss of fluid.

Fuel is loaded in wing tanks primarily to relieve wing bending moment; fuel in the fuselage tanks increases bending moment and limits manoeuvre load.

A pressurisation outflow valve modulates cabin altitude; maximum cabin differential pressure is a structural limit, and positive/negative relief valves protect the hull.

Landing gear retraction is prevented by air/ground logic (squat switches); gear-up warning is inhibited below a low power setting on some types to avoid nuisance warnings.

A gas turbine's compressor stall (surge) produces a bang, vibration, and EGT rise; recovery is reduction of thrust and smooth re-application.

Fire detection uses loop-type detectors in engines and APU; a dual-loop system with fault logic can still detect fire with one loop failed.

Anti-ice on the wing leading edge is usually thermal (bleed) and on the tail often electrical; ice on the tail can be undetected and causes pitch control loss.

APU provides electrical power and bleed air on the ground and can supply bleed for engine start; APU bleed and engine bleed are usually interlocked.

Pitot-static: ASI uses total pressure minus static; VSI uses rate of change of static pressure; altimeter uses static pressure only.

Blocked pitot tube: ASI behaves like an altimeter (climbs in climb), blocked static: ASI over-reads in climb and under-reads in descent.

Altitude errors: position error (static port location), instrument error, and temperature error; altimeters are calibrated to ISA and over-read in cold air at high altitude.

Mach number is computed from impact pressure and static pressure; Machmeter indications are independent of temperature error in the same way as the ASI.

Gyroscope rigidity in space gives the attitude indicator and heading indicator their references; precession is the basis of the turn indicator.

A turn coordinator shows rate of turn and roll; a turn-and-slip indicator shows rate of turn only; both are rate gyros, not attitude gyros.

The magnetic compass has turning and acceleration errors; it is reliable only in straight, level, unaccelerated flight, and the deviation card corrects residual error.

EFIS displays replace mechanical instruments; a red line or amber box indicates a limit exceedance, and a comparator monitors duplicated inputs for disagreement.

Radio altimeter measures height above terrain using frequency modulation; it is used for low-altitude callouts and is invalid above its design range.

Mass and balance: total mass = empty mass + traffic load + fuel; CG position = sum of (mass x arm) / total mass.

Forward CG increases stall speed and pitch-down tendency, reduces cruise efficiency; aft CG reduces longitudinal stability and can cause pitch-up departure.

Maximum zero-fuel mass (MZFM) limits structural load without fuel; maximum take-off mass (MTOM) and maximum landing mass (MLM) limit total mass at those phases.

Regulated landing mass may be exceeded in an emergency, but a landing with mass above MLM requires an overweight landing inspection.

Load sheet: LIZ (last item zero fuel mass) and DOI (dry operating index) are used; final CG must fall within the certified envelope for take-off and landing.

Floor loading limits are separate from total mass limits; concentrated loads require spreader plates.

Fuel density varies with temperature; mass-based fuel planning must convert volume to mass using actual density, not a fixed 0.72 kg/L.

A CG shift of 1% MAC can change trim drag and fuel burn measurably; aft CG within limits reduces trim drag and improves range.

Take-off distance available (TODA) = TORA + clearway; accelerate-stop distance available (ASDA) = TORA + stopway.

Balanced field length: V1 chosen so that accelerate-stop distance equals accelerate-go distance; V1 must be at least VMCG and at most VR.

V speeds: V1 decision speed, VR rotation, V2 take-off safety speed, VMCG minimum control speed on ground, VMCA minimum control speed airborne.

Climb gradients: for a twin, second-segment climb requires 2.4% (with one engine out); landing climb requires 3.2% (all engines) and 2.7% (one engine) for twins.

Density altitude: high temperature, high elevation, and high humidity reduce air density and increase take-off distance and reduce climb performance.

Runway condition affects braking: wet, contaminated, or slippery runway increases landing distance; contaminated runway reduces tyre friction and can cause aquaplaning.

Landing distance required = air distance from 50 ft plus ground roll; it must not exceed LDA, and a 15% factor applies to dry runways for commercial operations.

Wind shear and gust corrections add to approach speed; a headwind component reduces ground roll but must be accounted for conservatively in performance.

Fuel plan: trip fuel + contingency (typically 5% of trip fuel) + alternate fuel + final reserve (30 min holding) + extra fuel.

PIC must ensure fuel on board covers trip, alternate, and final reserve; in-flight fuel monitoring compares actual burn to planned burn at each waypoint.

Equal time point (ETP) is where time to continue equals time to return; it depends on wind, not just distance.

Point of no return (PNR) is limited by fuel available; it is calculated from fuel remaining, fuel required to destination and alternate, and burn rate.

True track and heading: heading = track - wind correction angle; drift = wind speed x sin(wind angle) / TAS (small-angle approximation).

Cruise altitude selection considers wind (headwind favours lower altitude, tailwind favours higher), temperature, and step-climb capability.

Flight plan route uses ATS routes, and the ICAO flight plan form requires aircraft identification, type, wake category, route, and EOBT.

ETOPS: for twin-engine aircraft, the diversion time limit determines the maximum distance from an adequate aerodrome; fuel and systems must support the diversion.

Hypoxia: symptoms include euphoria, impaired judgement, and cyanosis; time of useful consciousness at FL350 is about 30-60 seconds (rapid decompression).

Hyperventilation produces dizziness and tingling; it is treated by controlled breathing and, if suspected hypoxia, by oxygen and descent.

Spatial disorientation: the somatogravic illusion causes a pitch-up sensation during acceleration; the leans occur after a sudden roll recovery.

Crew resource management: assertiveness, briefing, and cross-monitoring reduce error; authority gradient too steep or too flat degrades communication.

Circadian rhythm: alertness lowest around 0300-0600 local; fatigue is cumulative and not fully restored by a single short rest.

G tolerance: anti-G straining manoeuvre and G-suit improve tolerance; AGSM involves muscle tension and breathing, not breath-holding.

Vision: night vision uses rods, which are poor at detail and colour and adapt slowly; scanning at night should use off-centre viewing.

Stress and performance follow an inverted-U curve; moderate stress improves performance, but high stress narrows attention and increases error.

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

QNH is pressure reduced to sea level; QFE is pressure at aerodrome elevation; QNE (1013.25) is used above transition altitude.

The tropopause is higher and colder at the equator than at the poles; jet streams form near the tropopause and are strongest in winter.

Thunderstorm life cycle: cumulus, mature, dissipating; the mature stage has both updrafts and downdrafts and produces the most severe hazards.

Icing: clear ice forms in large supercooled droplets (stratiform), rime ice in small droplets (cumuliform); both degrade lift and increase drag.

Fog forms when temperature reaches dew point; radiation fog needs clear skies, light wind, and high humidity, and usually dissipates after sunrise.

Wind shear on approach is reported as microburst or gust front; a sudden headwind loss causes airspeed loss and requires immediate go-around.

Altimeter setting errors: flying from high to low pressure without resetting causes the altimeter to over-read, giving a lower true altitude than indicated.

Great circle is the shortest path on a sphere; rhumb line is a constant track, longer than great circle except on the equator or a meridian.

Mercator projection: rhumb lines are straight, scale increases with latitude, and great circles are curved (concave toward the equator).

Lambert conformal conic: great circles are approximately straight lines, used for charts in mid-latitudes; scale is constant along standard parallels.

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

Conversion: true bearing = magnetic bearing + variation (east variation added); compass heading accounts for deviation.

Distance along a meridian = change in latitude in minutes; along a parallel = change in longitude in minutes x cos(latitude).

The 1-in-60 rule: a 1° track error over 60 NM gives 1 NM off track; correction angle = (distance off track x 60) / distance flown.

Solar and sidereal time: 1 hour of local time = 15° of longitude; sunrise/sunset tables are computed for latitude and date.

VOR: 108.0-117.95 MHz, line-of-sight; radial is magnetic from the station; CDI centred with TO/FROM flag indicates on-course.

DME: slant range, not ground distance; error is largest directly overhead; DME paired with VOR gives rho-theta position.

ILS: localiser 108.10-111.95 MHz (odd tenths), glide path 329.15-335.0 MHz; category I decision height 200 ft, II 100 ft, III 0-50 ft.

NDB/ADF: low-frequency (190-1755 kHz), susceptible to night effect and static; ADF bearing is relative to aircraft heading.

GNSS: position from satellite ranging; RAIM monitors integrity; receiver autonomous integrity monitoring requires adequate satellite geometry.

RNAV/GNSS approach minima depend on SBAS/GBAS augmentation; LPV approaches provide vertical guidance without ground-based glide path.

Radar: primary radar provides position only; secondary radar (SSR) uses transponder codes and altitude (Mode C) for separation.

TCAS: traffic advisories and resolution advisories; RA commands must be followed, and TCAS is inhibited below a set altitude (usually 1000 ft).

Take-off briefing includes rejected take-off decision, engine failure actions, and emergency return considerations; V1 callout is mandatory.

Sterile flight deck: no non-essential communication below 10 000 ft; critical phases include taxi, take-off, approach, and landing.

Emergency descent: use of oxygen masks, descent to 10 000 ft or MSA, and broadcast of MAYDAY; cabin crew must be alerted.

Decompression: don oxygen first, then descend; time of useful consciousness decreases rapidly above FL350.

Fuel emergency: declare MAYDAY FUEL when fuel is below final reserve; ATC gives priority and the aircraft lands at the nearest suitable aerodrome.

Runway incursion prevention: readback of hold-short instructions, use of exterior lights, and sterile cockpit during taxi.

Checklist discipline: challenge-response format, and no checklist item may be assumed complete without verification.

Ditching and evacuation: brace position, exit selection, and life jacket use; evacuation commands and slide use depend on conditions.

Lift = CL x 0.5 x rho x V^2 x S; induced drag = CDi x 0.5 x rho x V^2 x S; induced drag decreases with increasing speed.

Critical angle of attack is the stall angle; stall speed increases with mass and load factor: VS(new) = VS x sqrt(load factor).

Load factor n = L/W; in a level turn, n = 1/cos(bank angle); at 60° bank n = 2.

Boundary layer: laminar flow has lower skin friction; transition to turbulent increases drag but resists separation.

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

Sweepback increases critical Mach number and lateral stability but reduces lift coefficient and can cause Dutch roll.

Dihedral gives lateral stability; too much dihedral can cause Dutch roll, and anhedral is used on some high-wing aircraft.

Trim: elevator trim balances stick force; a forward CG requires more nose-up trim, increasing trim drag.

Standard phraseology: readback of clearances, altitudes, headings, and frequencies is mandatory; use of standard words (ROGER, WILCO, AFFIRM) avoids ambiguity.

Distress (MAYDAY) has priority over urgency (PAN-PAN) and routine calls; distress traffic is handled on the distress frequency or the working frequency.

VHF propagation is line-of-sight; range in nautical miles is approximately 1.23 x sqrt(height in feet).

HF is used for oceanic and remote communications; SELCAL reduces crew monitoring of HF.

Lost communication: squawk 7600, continue according to the last clearance or the filed route, and attempt contact on other frequencies.

Position reports and estimates are made in the standard format; the report is repeated only if requested or if the estimate changes by more than 2 minutes.

Emergency frequency 121.5 MHz is monitored by ATC and many aircraft; a distress call includes MAYDAY, callsign, position, and nature of emergency.

Readback errors are a major cause of incidents; if a clearance is unclear, request clarification rather than assuming.