NCAA PPL (Helicopter) Theory Exam cheat sheet

ICAO Annex 2 rules of the air apply in international flight; national AIP differences override where the State has filed them.

VFR minima (ICAO Annex 2, uncontrolled airspace below 900 m/3000 ft AMSL): 5 km flight visibility, 1500 m horizontally and 300 m (1000 ft) vertically from cloud.

At or above 900 m (3000 ft) AMSL: 8 km visibility, 1500 m horizontal and 300 m vertical cloud separation.

Special VFR is a clearance, not a right: it requires ATC approval and remains subject to the State's published minima.

Helicopter minimum fuel: land with at least 30 minutes cruise fuel; helicopter emergency medical service flights may be reduced to 20 minutes.

A helicopter may operate with a sling load only under the conditions of its certificate of airworthiness and the operator's approved procedures.

Right-of-way: a helicopter at low level gives way to all other traffic; converging aircraft of the same category, the one on the right has right-of-way.

An aircraft in distress has right-of-way over all others; on receiving a distress transmission, other aircraft must give way and assist if able.

Main rotor systems: fully articulated (flapping, lead-lag, feathering hinges), semi-rigid (teetering, two blades), and rigid (bearingless composite flexure).

Lead-lag (drag) hinges relieve in-plane Coriolis forces; their dampers prevent ground resonance and blade oscillation.

Ground resonance occurs when blade lead-lag frequency matches airframe natural frequency on the ground; correct action is immediate liftoff or shutdown.

Tail rotor types: conventional (pusher), Fenestron (shrouded), NOTAR (no tail rotor, uses circulation control and direct jet thrust).

Freewheeling unit (sprag clutch) disengages the engine from the rotor during autorotation, allowing the rotor to turn freely.

Turboshaft engine limits: N1/Ng and N2/Nr percentages, TOT/ITT, and torque; exceedance of any limit requires a logbook entry and inspection.

Mast bumping: excessive flapping on a semi-rigid rotor lets the blade grip contact the mast; prevented by limiting cyclic input at low G.

Hydraulic failure in a helicopter with irreversible controls increases control forces and may require reduced airspeed and gentle manoeuvring.

Mass and balance: total mass = empty mass + crew + passengers + fuel + baggage; CG must lie within the forward and aft limits at all times.

Density altitude = pressure altitude + 120 x (OAT - ISA temperature at that level); ISA at sea level is 15 °C, lapse 1.98 °C per 1000 ft.

Hover performance degrades with density altitude: IGE hover ceiling is higher than OGE hover ceiling for the same mass.

Power required in hover increases with mass; power available decreases with density altitude and temperature, reducing the margin.

Autorotation descent rate increases with mass; the flare and landing require careful energy management at high gross mass.

Takeoff and landing performance charts are valid only for the conditions in the chart's notes (wind, slope, surface, anti-ice use).

Fuel planning: trip fuel + contingency + alternate (if required) + final reserve; helicopter final reserve is 30 minutes at cruise.

CG too far forward increases nose-down pitch authority demand; CG too far aft reduces cyclic authority and can cause mast bumping.

Hypoxia: symptoms include euphoria, impaired judgement, and cyanosis; time of useful consciousness at 25 000 ft is about 3-5 minutes.

Hyperventilation and hypoxia share symptoms; hyperventilation is treated by controlled breathing, hypoxia by supplemental oxygen and descent.

Spatial disorientation: vestibular illusions include the leans, somatogravic (false climb on acceleration), and Coriolis illusion.

Fatigue: acute fatigue is relieved by rest; cumulative fatigue requires sleep debt recovery, not caffeine or motivation.

Stress: performance peaks at moderate arousal (Yerkes-Dodson); high arousal narrows attention and increases error rates.

Vision: rods detect motion and low light, cones provide colour and detail; dark adaptation takes about 30 minutes.

Carbon monoxide poisoning from exhaust leaks causes headache, confusion, and cherry-red skin; treat with 100% oxygen and land.

Crew resource management: assertiveness, briefing, cross-check, and callouts reduce error; the captain retains final authority.

ISA: sea level 15 °C, 1013.25 hPa, lapse rate 1.98 °C/1000 ft up to the tropopause (about 36 000 ft).

QNH is pressure reduced to sea level; QFE is pressure at the aerodrome; QNE is 1013.25 hPa used above the transition altitude.

Density altitude affects performance more than pressure altitude alone; high temperature and high humidity reduce performance.

Wind shear on approach: a sudden headwind loss causes airspeed loss and sink; go-around if airspeed or sink rate is unacceptable.

Thunderstorms: avoid by at least 20 nm; hail, microbursts, and turbulence extend well beyond the visible cloud.

Mountain waves: lenticular clouds and rotor clouds indicate severe turbulence; expect downdrafts on the lee side.

Icing: carburettor icing can occur at temperatures between -7 °C and +21 °C with high humidity; use carb heat as required.

Fog forms when temperature reaches dew point; radiation fog is most likely on clear, calm nights with high humidity.

True course + wind correction = true heading; true heading ± magnetic variation = magnetic heading; magnetic heading ± deviation = compass heading.

1 in 60 rule: a 1° error over 60 nm gives 1 nm off track; use it for mental drift and closing-angle calculations.

Track error (°) = (distance off track / distance flown) × 60; closing angle = (distance off track / distance to go) × 60.

Great circle routes are the shortest path on a sphere; rhumb lines cross all meridians at the same angle.

VOR: radials are magnetic bearings from the station; CDI centred with TO/FROM flag indicates on-course.

GPS: RAIM predicts integrity; check satellite coverage before relying on GPS for an approach.

Dead reckoning: groundspeed = distance / time; fuel = fuel flow × time; always add a contingency.

Altimetry: set QNH below transition altitude; above, set 1013.25 hPa and fly flight levels.

Pre-flight: check NOTAMs, weather, mass and balance, fuel, and performance; brief passengers on doors, belts, and emergency exits.

Normal takeoff: confirm power available, hover check, transition to forward flight, and maintain takeoff safety speed.

Autorotation: lower collective immediately, maintain rotor RPM, select landing area, flare at about 50 ft, cushion with collective.

Engine failure in hover: if low, land immediately; if high, lower collective and execute autorotation.

Tail rotor failure: at low speed, close throttle and land; at speed, maintain forward speed and fly to a suitable landing area.

Emergency calls: MAYDAY for distress, PAN-PAN for urgency; give position, nature of emergency, intentions, and persons on board.

Fire: shut off fuel and electrical, use extinguisher, land as soon as possible; do not restart a fire-affected engine.

Sling load operations: use a qualified hook, brief the load, avoid abrupt control inputs, and maintain load clearance.

Bernoulli and Newton: lift is produced by pressure difference and by downward deflection of air; both explanations are valid.

Induced flow and induced drag: induced drag decreases with airspeed; profile drag increases with airspeed squared.

Translational lift occurs at about 15-20 kt effective translational lift; it improves hover performance and reduces power required.

Dissymmetry of lift: advancing blade sees higher airspeed, retreating blade lower; flapping and cyclic feathering equalise lift.

Retreating blade stall: occurs at high speed, high mass, low RPM, and high density altitude; symptoms include pitch-up and vibration.

Autorotation: rotor is driven by upward airflow; RPM is controlled by collective, and forward speed extends glide range.

Ground effect: IGE hover requires less power because the rotor downwash is restricted; OGE hover requires more power.

Settling with power (vortex ring state): descent rate 300-800 ft/min with low airspeed and high power; recover with forward cyclic and collective reduction.

Phonetic alphabet: Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu.

Distress call: MAYDAY spoken three times; urgency call: PAN-PAN spoken three times.

Readback: clearances, runway assignments, altimeter settings, and hold short instructions must be read back.

Emergency frequency is 121.5 MHz; use it for distress and for homing by ATC or rescue services.

Standard phraseology: "wilco" means will comply; "roger" means received; "affirm" means yes; "negative" means no.

Position report: identification, position, time, altitude/flight level, next position and ETA.

Aerodrome traffic: report downwind, final, and clear of runway; use the aerodrome frequency specified in the AIP.

Lost communication: squawk 7600, continue VFR, land at the nearest suitable aerodrome, and report to ATC.

ICAO Annex 2 rules of the air apply in international flight; national AIP differences override where the State has filed them.

VFR minima (ICAO Annex 2, uncontrolled airspace below 900 m/3000 ft AMSL): 5 km flight visibility, 1500 m horizontally and 300 m (1000 ft) vertically from cloud.

At or above 900 m (3000 ft) AMSL: 8 km visibility, 1500 m horizontal and 300 m vertical cloud separation.

Special VFR is a clearance, not a right: it requires ATC approval and remains subject to the State's published minima.

Helicopter minimum fuel: land with at least 30 minutes cruise fuel; helicopter emergency medical service flights may be reduced to 20 minutes.

A helicopter may operate with a sling load only under the conditions of its certificate of airworthiness and the operator's approved procedures.

Right-of-way: a helicopter at low level gives way to all other traffic; converging aircraft of the same category, the one on the right has right-of-way.

An aircraft in distress has right-of-way over all others; on receiving a distress transmission, other aircraft must give way and assist if able.

Main rotor systems: fully articulated (flapping, lead-lag, feathering hinges), semi-rigid (teetering, two blades), and rigid (bearingless composite flexure).

Lead-lag (drag) hinges relieve in-plane Coriolis forces; their dampers prevent ground resonance and blade oscillation.

Ground resonance occurs when blade lead-lag frequency matches airframe natural frequency on the ground; correct action is immediate liftoff or shutdown.

Tail rotor types: conventional (pusher), Fenestron (shrouded), NOTAR (no tail rotor, uses circulation control and direct jet thrust).

Freewheeling unit (sprag clutch) disengages the engine from the rotor during autorotation, allowing the rotor to turn freely.

Turboshaft engine limits: N1/Ng and N2/Nr percentages, TOT/ITT, and torque; exceedance of any limit requires a logbook entry and inspection.

Mast bumping: excessive flapping on a semi-rigid rotor lets the blade grip contact the mast; prevented by limiting cyclic input at low G.

Hydraulic failure in a helicopter with irreversible controls increases control forces and may require reduced airspeed and gentle manoeuvring.

Mass and balance: total mass = empty mass + crew + passengers + fuel + baggage; CG must lie within the forward and aft limits at all times.

Density altitude = pressure altitude + 120 x (OAT - ISA temperature at that level); ISA at sea level is 15 °C, lapse 1.98 °C per 1000 ft.

Hover performance degrades with density altitude: IGE hover ceiling is higher than OGE hover ceiling for the same mass.

Power required in hover increases with mass; power available decreases with density altitude and temperature, reducing the margin.

Autorotation descent rate increases with mass; the flare and landing require careful energy management at high gross mass.

Takeoff and landing performance charts are valid only for the conditions in the chart's notes (wind, slope, surface, anti-ice use).

Fuel planning: trip fuel + contingency + alternate (if required) + final reserve; helicopter final reserve is 30 minutes at cruise.

CG too far forward increases nose-down pitch authority demand; CG too far aft reduces cyclic authority and can cause mast bumping.

Hypoxia: symptoms include euphoria, impaired judgement, and cyanosis; time of useful consciousness at 25 000 ft is about 3-5 minutes.

Hyperventilation and hypoxia share symptoms; hyperventilation is treated by controlled breathing, hypoxia by supplemental oxygen and descent.

Spatial disorientation: vestibular illusions include the leans, somatogravic (false climb on acceleration), and Coriolis illusion.

Fatigue: acute fatigue is relieved by rest; cumulative fatigue requires sleep debt recovery, not caffeine or motivation.

Stress: performance peaks at moderate arousal (Yerkes-Dodson); high arousal narrows attention and increases error rates.

Vision: rods detect motion and low light, cones provide colour and detail; dark adaptation takes about 30 minutes.

Carbon monoxide poisoning from exhaust leaks causes headache, confusion, and cherry-red skin; treat with 100% oxygen and land.

Crew resource management: assertiveness, briefing, cross-check, and callouts reduce error; the captain retains final authority.

ISA: sea level 15 °C, 1013.25 hPa, lapse rate 1.98 °C/1000 ft up to the tropopause (about 36 000 ft).

QNH is pressure reduced to sea level; QFE is pressure at the aerodrome; QNE is 1013.25 hPa used above the transition altitude.

Density altitude affects performance more than pressure altitude alone; high temperature and high humidity reduce performance.

Wind shear on approach: a sudden headwind loss causes airspeed loss and sink; go-around if airspeed or sink rate is unacceptable.

Thunderstorms: avoid by at least 20 nm; hail, microbursts, and turbulence extend well beyond the visible cloud.

Mountain waves: lenticular clouds and rotor clouds indicate severe turbulence; expect downdrafts on the lee side.

Icing: carburettor icing can occur at temperatures between -7 °C and +21 °C with high humidity; use carb heat as required.

Fog forms when temperature reaches dew point; radiation fog is most likely on clear, calm nights with high humidity.

True course + wind correction = true heading; true heading ± magnetic variation = magnetic heading; magnetic heading ± deviation = compass heading.

1 in 60 rule: a 1° error over 60 nm gives 1 nm off track; use it for mental drift and closing-angle calculations.

Track error (°) = (distance off track / distance flown) × 60; closing angle = (distance off track / distance to go) × 60.

Great circle routes are the shortest path on a sphere; rhumb lines cross all meridians at the same angle.

VOR: radials are magnetic bearings from the station; CDI centred with TO/FROM flag indicates on-course.

GPS: RAIM predicts integrity; check satellite coverage before relying on GPS for an approach.

Dead reckoning: groundspeed = distance / time; fuel = fuel flow × time; always add a contingency.

Altimetry: set QNH below transition altitude; above, set 1013.25 hPa and fly flight levels.

Pre-flight: check NOTAMs, weather, mass and balance, fuel, and performance; brief passengers on doors, belts, and emergency exits.

Normal takeoff: confirm power available, hover check, transition to forward flight, and maintain takeoff safety speed.

Autorotation: lower collective immediately, maintain rotor RPM, select landing area, flare at about 50 ft, cushion with collective.

Engine failure in hover: if low, land immediately; if high, lower collective and execute autorotation.

Tail rotor failure: at low speed, close throttle and land; at speed, maintain forward speed and fly to a suitable landing area.

Emergency calls: MAYDAY for distress, PAN-PAN for urgency; give position, nature of emergency, intentions, and persons on board.

Fire: shut off fuel and electrical, use extinguisher, land as soon as possible; do not restart a fire-affected engine.

Sling load operations: use a qualified hook, brief the load, avoid abrupt control inputs, and maintain load clearance.

Bernoulli and Newton: lift is produced by pressure difference and by downward deflection of air; both explanations are valid.

Induced flow and induced drag: induced drag decreases with airspeed; profile drag increases with airspeed squared.

Translational lift occurs at about 15-20 kt effective translational lift; it improves hover performance and reduces power required.

Dissymmetry of lift: advancing blade sees higher airspeed, retreating blade lower; flapping and cyclic feathering equalise lift.

Retreating blade stall: occurs at high speed, high mass, low RPM, and high density altitude; symptoms include pitch-up and vibration.

Autorotation: rotor is driven by upward airflow; RPM is controlled by collective, and forward speed extends glide range.

Ground effect: IGE hover requires less power because the rotor downwash is restricted; OGE hover requires more power.

Settling with power (vortex ring state): descent rate 300-800 ft/min with low airspeed and high power; recover with forward cyclic and collective reduction.

Phonetic alphabet: Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu.

Distress call: MAYDAY spoken three times; urgency call: PAN-PAN spoken three times.

Readback: clearances, runway assignments, altimeter settings, and hold short instructions must be read back.

Emergency frequency is 121.5 MHz; use it for distress and for homing by ATC or rescue services.

Standard phraseology: "wilco" means will comply; "roger" means received; "affirm" means yes; "negative" means no.

Position report: identification, position, time, altitude/flight level, next position and ETA.

Aerodrome traffic: report downwind, final, and clear of runway; use the aerodrome frequency specified in the AIP.

Lost communication: squawk 7600, continue VFR, land at the nearest suitable aerodrome, and report to ATC.