KCAA IR Theory cheat sheet

KCAA is the civil aviation authority established under the Civil Aviation Act; it issues licences, certificates and approvals and oversees the Kenya Civil Aviation Regulations (KCARs), which are modelled on ICAO Annexes.

KCAR Part 2 governs licensing of flight crew; an IR rating is issued, revalidated and renewed under this Part, and privileges may only be exercised when the rating is valid and the holder meets recent experience and medical requirements.

Instrument rating validity in Kenya follows the KCAR revalidation cycle (typically 12 months for single-pilot IR); renewal after expiry normally requires a proficiency check and may require additional training at an approved organisation.

An IR holder may act as PIC under IFR only if the aircraft is appropriately equipped and certified for IFR, and the pilot holds a valid Class 1 medical (Class 2 for some private privileges) plus a valid instrument rating.

ICAO Annex 2 Rules of the Air apply: VMC minima in controlled airspace at/above 3 050 m (10 000 ft) AMSL are 8 km flight visibility, 1 500 m horizontal and 300 m (1 000 ft) vertical distance from cloud.

Semi-circular rule (Annex 2): IFR/VFR cruising levels are based on magnetic track, 000–179° use odd thousands (FL 090, 110, 130...), 180–359° use even thousands (FL 100, 120, 140...), with RVSM applying 29 000–41 000 ft.

Kenya's airspace includes Nairobi FIR (HKNA) with controlled airspace around Nairobi and Mombasa; entry requires an ATC clearance, and position reporting is mandatory on designated routes and at compulsory reporting points.

Aircraft must carry documents under KCAR/ICAO Annex 6: certificate of registration, certificate of airworthiness, crew licences, journey log, operations manual where applicable, and radio station licence; the IR candidate must know which documents are carried and their validity.

Kenya requires an ELT (406 MHz) for most operations under KCAR Part 12/Annex 6 and mandates occurrence reporting; serious incidents must be reported to the KCAA Accident Investigation/AAID without delay.

Pitot-static system: the ASI uses pitot (total) pressure and static pressure, the altimeter uses static pressure only, and the VSI uses a calibrated leak/chamber referenced to static pressure; blockage of the static source affects all three.

Altimeter errors: with QNH set, indication is height above mean sea level; with QFE set, it is height above the reference datum. Flying from high to low pressure without resetting QNH causes the aircraft to be lower than indicated.

ASI errors: position (installation) error, instrument error, compressibility error at high speed/altitude, and density error (IAS vs TAS). TAS increases with altitude for a given IAS; TAS ≈ IAS + 2% per 1 000 ft (approximate).

VSI lag: the instrument shows a lag of several seconds and indicates a trend, not instantaneous vertical speed; a rapid push-pull manoeuvre causes over/under-reading.

Gyroscopic instruments: attitude indicator and heading indicator are driven by vacuum/air or electrically; the turn coordinator/turn-and-slip uses a rate gyro and shows rate of turn plus slip/skid via the inclinometer ball.

Heading indicator: precession/drift requires periodic alignment with the magnetic compass in straight and level flight; it is not north-seeking and is subject to apparent drift due to Earth's rotation and transport wander.

Magnetic compass: turning and acceleration errors (northerly/southerly turning error, acceleration error on east/west headings) and deviation from aircraft magnetism; deviation card must be applied to give magnetic heading.

Glass cockpit/EFIS: PFD shows attitude, airspeed, altitude, heading and ILS; MFD shows navigation display; failures may cause reversion to standby instruments; the IR pilot must know standby instrument use and degraded-mode procedures.

Radio altimeter: measures height above terrain (AGL) using radar; used for decision height on precision approaches and for GPWS/EGPWS; it is not affected by QNH setting.

Fuel planning: trip fuel + contingency (typically 5% of trip fuel for IFR) + alternate fuel + final reserve (typically 30 minutes holding for turbine aircraft) + taxi fuel = minimum required fuel; extra fuel is added at the commander's discretion.

TAS/Mach and wind: use the navigation computer or formula GS = TAS ± wind component; drift angle = arcsin(wind speed × sin(angle off track)/TAS); heading = track − drift.

Flight plan (ICAO): filed at least 60 minutes before departure for IFR; includes aircraft identification, type, wake category, equipment, departure/destination, route, levels, EET, alternate and endurance; changes require ATC notification.

Point of no return (PNR) and equal time point (ETP): PNR is where time to destination equals time back to departure; ETP is where time to either of two airfields is equal, accounting for fuel and wind.

Critical fuel point: the point where, on a diversion, fuel would reach the final reserve; must be computed for the most limiting scenario (depressurisation, engine failure) on ETOPS/long-range flights.

Climb/descent: rule of thumb for descent planning is 3 × altitude (in thousands of feet) = track miles; descent rate for a 3° path ≈ 5 × GS (knots) ft/min.

Weight and balance: compute zero-fuel weight, take-off weight and landing weight against limits; CG must remain within the forward and aft limits throughout flight, including fuel burn.

Monitoring: in-flight, compare actual fuel burn and groundspeed against the flight plan; a 10% fuel discrepancy or unexpected headwind requires re-planning and, if needed, a diversion decision.

Hypoxia: symptoms include euphoria, impaired judgement, cyanosis and reduced night vision; time of useful consciousness at FL 350 is roughly 30–60 seconds; supplemental oxygen is required above 10 000 ft (or per KCAR) and for the crew at all times above 13 000 ft.

Spatial disorientation: somatogravic illusion (false climb/descent during acceleration/deceleration) and the leans are common; the remedy is to trust the instruments and maintain a standard scan.

The vestibular system (semicircular canals, otolith organs) senses angular acceleration and gravity, not reliable attitude at constant velocity; visual illusions include black hole approach and runway slope illusion.

Stress and fatigue: circadian low points around 03:00–06:00 and 15:00–17:00 local; fatigue impairs reaction time and decision-making; FRMS and flight/duty time limits (KCAR Part 8/Annex 6) manage this.

Workload and automation: automation complacency and mode confusion are hazards in glass cockpits; always verify mode annunciations and maintain basic instrument flying proficiency.

Vision and hearing: night vision uses rods (peripheral, slow adaptation); looking 10–15° off-centre improves night detection; noise-induced hearing loss is cumulative and headsets are protective.

Decompression and barotrauma: rapid decompression requires immediate oxygen, emergency descent to 10 000 ft or below; ear/sinus barotrauma is managed by Valsalva or Toynbee manoeuvres and by not flying with a cold.

Crew resource management: assertiveness, briefings, cross-check and callouts reduce error; the sterile cockpit rule prohibits non-essential activity below 10 000 ft (or per operator).

ISA: sea-level temperature 15°C, pressure 1013.25 hPa, lapse rate 1.98°C per 1 000 ft up to 11 km; tropopause at about 36 090 ft where temperature is about −56.5°C.

Altimetry: QNH gives altitude above MSL; QFE gives height above a datum; flight levels use standard pressure 1013.25 hPa. When flying from high to low pressure or high to low temperature, the true altitude is lower than indicated.

Cloud types: cumulonimbus (CB) produces severe turbulence, icing, hail and microbursts; avoid by at least 20 nm and do not attempt to overfly above FL 400 unless certified; embedded CB in fronts is a major IFR hazard.

Icing: airframe icing occurs between 0°C and −20°C in visible moisture; severe icing risk is greatest in freezing rain/drizzle; anti-ice/de-ice and escape to warmer or colder air are the remedies.

Thunderstorms: stages are cumulus, mature and dissipating; the mature stage has both up and downdrafts; microbursts can cause a 30–50 kt airspeed loss on approach; wind shear alerts and PIREPs must be heeded.

Fronts: cold fronts have narrow bands of heavy precipitation and rapid wind shifts; warm fronts have wide, layered cloud and stable precipitation; occluded fronts combine both and can be hazardous.

Kenya climate: equatorial, with the long rains (March–May) and short rains (October–December); convective CB activity is common in the afternoon over the highlands; the Inter-Tropical Convergence Zone drives seasonal weather.

Mountain wave/lee turbulence: downslope winds and rotor turbulence occur on the lee of the Aberdares, Mount Kenya and Kilimanjaro; expect strong turbulence and altimeter errors in mountain wave.

NDB/ADF: the ADF needle points to the station relative to the aircraft; relative bearing + magnetic heading = magnetic bearing to the station; the needle is subject to night effect, coastal refraction and thunderstorm interference.

VOR: provides magnetic bearing from the station (radial); CDI centred with TO/FROM indicates on-course; reverse sensing occurs if the OBS is set incorrectly; VOR has line-of-sight range, roughly 1.23 × √height (ft) nautical miles.

DME: slant range in nautical miles; indicated DME distance is greater than ground distance, especially at high altitude and close to the station; DME is paired with VOR or ILS.

ILS: localiser provides lateral guidance (108.10–111.95 MHz), glideslope provides vertical guidance (329.15–335 MHz); a 3° glideslope gives about 300 ft per nautical mile; marker beacons and DME provide range.

RNAV/GNSS: RAIM (receiver autonomous integrity monitoring) must be available for standalone GPS approaches; an RAIM prediction is required before departure; WAAS/SBAS provides vertical guidance (LPV) where available.

Radar: primary radar uses skin paint, secondary radar uses transponder replies; transponder codes 7500 (hijack), 7600 (radio failure), 7700 (emergency); Mode C provides altitude reporting.

Ground-based aids: NDB (190–535 kHz), VOR (108–117.95 MHz), ILS localiser (108–112 MHz), glideslope (329–335 MHz), DME (960–1215 MHz), GNSS (L1 1575.42 MHz).

Radio failure: squawk 7600, continue under the last clearance or per the published lost-communication procedure; in IMC, follow the route and levels specified in the AIP/approach procedure.

IFR clearance: read back the clearance including route, level, speed and any crossing restrictions; the initial clearance may include a SID; verify the SID against the chart before departure.

Departure: standard instrument departure (SID) provides obstacle clearance and ATC separation; climb gradient must be met (typically 3.3% / 200 ft per nm) or an alternate procedure used.

Approach categories: precision (ILS, GLS), approach with vertical guidance (LNAV/VNAV, LPV), and non-precision (VOR, NDB, LNAV, LOC); each has a minimum descent altitude (MDA) or decision altitude (DA/DH).

Approach minima: DA/DH applies to precision and APV approaches; MDA applies to non-precision; the missed approach must be initiated at the DA/DH or MAPt, not after.

Holding: standard holding pattern is right turns, 1-minute inbound legs (or DME/gndspeed based); entry is direct, parallel or teardrop depending on the aircraft's heading relative to the holding fix.

Missed approach: climb on the published track and gradient to the missed approach altitude; do not turn before the MAPt unless the procedure specifies; advise ATC.

RNAV/GNSS approaches: LNAV, LNAV/VNAV and LPV minima; the pilot must verify RAIM, the correct baro setting, and the final approach segment; LPV requires SBAS.

Reduced vertical separation minimum (RVSM): applies between FL 290 and FL 410; aircraft must be RVSM-approved with altimetry system accuracy and autopilot; non-RVSM aircraft require a specific clearance.

KCAA is the civil aviation authority established under the Civil Aviation Act; it issues licences, certificates and approvals and oversees the Kenya Civil Aviation Regulations (KCARs), which are modelled on ICAO Annexes.

KCAR Part 2 governs licensing of flight crew; an IR rating is issued, revalidated and renewed under this Part, and privileges may only be exercised when the rating is valid and the holder meets recent experience and medical requirements.

Instrument rating validity in Kenya follows the KCAR revalidation cycle (typically 12 months for single-pilot IR); renewal after expiry normally requires a proficiency check and may require additional training at an approved organisation.

An IR holder may act as PIC under IFR only if the aircraft is appropriately equipped and certified for IFR, and the pilot holds a valid Class 1 medical (Class 2 for some private privileges) plus a valid instrument rating.

ICAO Annex 2 Rules of the Air apply: VMC minima in controlled airspace at/above 3 050 m (10 000 ft) AMSL are 8 km flight visibility, 1 500 m horizontal and 300 m (1 000 ft) vertical distance from cloud.

Semi-circular rule (Annex 2): IFR/VFR cruising levels are based on magnetic track, 000–179° use odd thousands (FL 090, 110, 130...), 180–359° use even thousands (FL 100, 120, 140...), with RVSM applying 29 000–41 000 ft.

Kenya's airspace includes Nairobi FIR (HKNA) with controlled airspace around Nairobi and Mombasa; entry requires an ATC clearance, and position reporting is mandatory on designated routes and at compulsory reporting points.

Aircraft must carry documents under KCAR/ICAO Annex 6: certificate of registration, certificate of airworthiness, crew licences, journey log, operations manual where applicable, and radio station licence; the IR candidate must know which documents are carried and their validity.

Kenya requires an ELT (406 MHz) for most operations under KCAR Part 12/Annex 6 and mandates occurrence reporting; serious incidents must be reported to the KCAA Accident Investigation/AAID without delay.

Pitot-static system: the ASI uses pitot (total) pressure and static pressure, the altimeter uses static pressure only, and the VSI uses a calibrated leak/chamber referenced to static pressure; blockage of the static source affects all three.

Altimeter errors: with QNH set, indication is height above mean sea level; with QFE set, it is height above the reference datum. Flying from high to low pressure without resetting QNH causes the aircraft to be lower than indicated.

ASI errors: position (installation) error, instrument error, compressibility error at high speed/altitude, and density error (IAS vs TAS). TAS increases with altitude for a given IAS; TAS ≈ IAS + 2% per 1 000 ft (approximate).

VSI lag: the instrument shows a lag of several seconds and indicates a trend, not instantaneous vertical speed; a rapid push-pull manoeuvre causes over/under-reading.

Gyroscopic instruments: attitude indicator and heading indicator are driven by vacuum/air or electrically; the turn coordinator/turn-and-slip uses a rate gyro and shows rate of turn plus slip/skid via the inclinometer ball.

Heading indicator: precession/drift requires periodic alignment with the magnetic compass in straight and level flight; it is not north-seeking and is subject to apparent drift due to Earth's rotation and transport wander.

Magnetic compass: turning and acceleration errors (northerly/southerly turning error, acceleration error on east/west headings) and deviation from aircraft magnetism; deviation card must be applied to give magnetic heading.

Glass cockpit/EFIS: PFD shows attitude, airspeed, altitude, heading and ILS; MFD shows navigation display; failures may cause reversion to standby instruments; the IR pilot must know standby instrument use and degraded-mode procedures.

Radio altimeter: measures height above terrain (AGL) using radar; used for decision height on precision approaches and for GPWS/EGPWS; it is not affected by QNH setting.

Fuel planning: trip fuel + contingency (typically 5% of trip fuel for IFR) + alternate fuel + final reserve (typically 30 minutes holding for turbine aircraft) + taxi fuel = minimum required fuel; extra fuel is added at the commander's discretion.

TAS/Mach and wind: use the navigation computer or formula GS = TAS ± wind component; drift angle = arcsin(wind speed × sin(angle off track)/TAS); heading = track − drift.

Flight plan (ICAO): filed at least 60 minutes before departure for IFR; includes aircraft identification, type, wake category, equipment, departure/destination, route, levels, EET, alternate and endurance; changes require ATC notification.

Point of no return (PNR) and equal time point (ETP): PNR is where time to destination equals time back to departure; ETP is where time to either of two airfields is equal, accounting for fuel and wind.

Critical fuel point: the point where, on a diversion, fuel would reach the final reserve; must be computed for the most limiting scenario (depressurisation, engine failure) on ETOPS/long-range flights.

Climb/descent: rule of thumb for descent planning is 3 × altitude (in thousands of feet) = track miles; descent rate for a 3° path ≈ 5 × GS (knots) ft/min.

Weight and balance: compute zero-fuel weight, take-off weight and landing weight against limits; CG must remain within the forward and aft limits throughout flight, including fuel burn.

Monitoring: in-flight, compare actual fuel burn and groundspeed against the flight plan; a 10% fuel discrepancy or unexpected headwind requires re-planning and, if needed, a diversion decision.

Hypoxia: symptoms include euphoria, impaired judgement, cyanosis and reduced night vision; time of useful consciousness at FL 350 is roughly 30–60 seconds; supplemental oxygen is required above 10 000 ft (or per KCAR) and for the crew at all times above 13 000 ft.

Spatial disorientation: somatogravic illusion (false climb/descent during acceleration/deceleration) and the leans are common; the remedy is to trust the instruments and maintain a standard scan.

The vestibular system (semicircular canals, otolith organs) senses angular acceleration and gravity, not reliable attitude at constant velocity; visual illusions include black hole approach and runway slope illusion.

Stress and fatigue: circadian low points around 03:00–06:00 and 15:00–17:00 local; fatigue impairs reaction time and decision-making; FRMS and flight/duty time limits (KCAR Part 8/Annex 6) manage this.

Workload and automation: automation complacency and mode confusion are hazards in glass cockpits; always verify mode annunciations and maintain basic instrument flying proficiency.

Vision and hearing: night vision uses rods (peripheral, slow adaptation); looking 10–15° off-centre improves night detection; noise-induced hearing loss is cumulative and headsets are protective.

Decompression and barotrauma: rapid decompression requires immediate oxygen, emergency descent to 10 000 ft or below; ear/sinus barotrauma is managed by Valsalva or Toynbee manoeuvres and by not flying with a cold.

Crew resource management: assertiveness, briefings, cross-check and callouts reduce error; the sterile cockpit rule prohibits non-essential activity below 10 000 ft (or per operator).

ISA: sea-level temperature 15°C, pressure 1013.25 hPa, lapse rate 1.98°C per 1 000 ft up to 11 km; tropopause at about 36 090 ft where temperature is about −56.5°C.

Altimetry: QNH gives altitude above MSL; QFE gives height above a datum; flight levels use standard pressure 1013.25 hPa. When flying from high to low pressure or high to low temperature, the true altitude is lower than indicated.

Cloud types: cumulonimbus (CB) produces severe turbulence, icing, hail and microbursts; avoid by at least 20 nm and do not attempt to overfly above FL 400 unless certified; embedded CB in fronts is a major IFR hazard.

Icing: airframe icing occurs between 0°C and −20°C in visible moisture; severe icing risk is greatest in freezing rain/drizzle; anti-ice/de-ice and escape to warmer or colder air are the remedies.

Thunderstorms: stages are cumulus, mature and dissipating; the mature stage has both up and downdrafts; microbursts can cause a 30–50 kt airspeed loss on approach; wind shear alerts and PIREPs must be heeded.

Fronts: cold fronts have narrow bands of heavy precipitation and rapid wind shifts; warm fronts have wide, layered cloud and stable precipitation; occluded fronts combine both and can be hazardous.

Kenya climate: equatorial, with the long rains (March–May) and short rains (October–December); convective CB activity is common in the afternoon over the highlands; the Inter-Tropical Convergence Zone drives seasonal weather.

Mountain wave/lee turbulence: downslope winds and rotor turbulence occur on the lee of the Aberdares, Mount Kenya and Kilimanjaro; expect strong turbulence and altimeter errors in mountain wave.

NDB/ADF: the ADF needle points to the station relative to the aircraft; relative bearing + magnetic heading = magnetic bearing to the station; the needle is subject to night effect, coastal refraction and thunderstorm interference.

VOR: provides magnetic bearing from the station (radial); CDI centred with TO/FROM indicates on-course; reverse sensing occurs if the OBS is set incorrectly; VOR has line-of-sight range, roughly 1.23 × √height (ft) nautical miles.

DME: slant range in nautical miles; indicated DME distance is greater than ground distance, especially at high altitude and close to the station; DME is paired with VOR or ILS.

ILS: localiser provides lateral guidance (108.10–111.95 MHz), glideslope provides vertical guidance (329.15–335 MHz); a 3° glideslope gives about 300 ft per nautical mile; marker beacons and DME provide range.

RNAV/GNSS: RAIM (receiver autonomous integrity monitoring) must be available for standalone GPS approaches; an RAIM prediction is required before departure; WAAS/SBAS provides vertical guidance (LPV) where available.

Radar: primary radar uses skin paint, secondary radar uses transponder replies; transponder codes 7500 (hijack), 7600 (radio failure), 7700 (emergency); Mode C provides altitude reporting.

Ground-based aids: NDB (190–535 kHz), VOR (108–117.95 MHz), ILS localiser (108–112 MHz), glideslope (329–335 MHz), DME (960–1215 MHz), GNSS (L1 1575.42 MHz).

Radio failure: squawk 7600, continue under the last clearance or per the published lost-communication procedure; in IMC, follow the route and levels specified in the AIP/approach procedure.

IFR clearance: read back the clearance including route, level, speed and any crossing restrictions; the initial clearance may include a SID; verify the SID against the chart before departure.

Departure: standard instrument departure (SID) provides obstacle clearance and ATC separation; climb gradient must be met (typically 3.3% / 200 ft per nm) or an alternate procedure used.

Approach categories: precision (ILS, GLS), approach with vertical guidance (LNAV/VNAV, LPV), and non-precision (VOR, NDB, LNAV, LOC); each has a minimum descent altitude (MDA) or decision altitude (DA/DH).

Approach minima: DA/DH applies to precision and APV approaches; MDA applies to non-precision; the missed approach must be initiated at the DA/DH or MAPt, not after.

Holding: standard holding pattern is right turns, 1-minute inbound legs (or DME/gndspeed based); entry is direct, parallel or teardrop depending on the aircraft's heading relative to the holding fix.

Missed approach: climb on the published track and gradient to the missed approach altitude; do not turn before the MAPt unless the procedure specifies; advise ATC.

RNAV/GNSS approaches: LNAV, LNAV/VNAV and LPV minima; the pilot must verify RAIM, the correct baro setting, and the final approach segment; LPV requires SBAS.

Reduced vertical separation minimum (RVSM): applies between FL 290 and FL 410; aircraft must be RVSM-approved with altimetry system accuracy and autopilot; non-RVSM aircraft require a specific clearance.