CAA NZ AME Licence Exam - Rotorcraft cheat sheet

Main rotor head types: fully articulated (separate flap, lead-lag and pitch hinges), semi-rigid/teetering (two-blade, underslung flapping hinge), and rigid/hingeless (loads carried by flexing composite or elastomeric elements).

Lead-lag (drag) hinges or elastomeric dampers absorb in-plane Coriolis and acceleration forces; a failed damper produces ground resonance, so damper condition and bolt torque are mandatory inspection items.

Ground resonance is a self-exciting coupling of rotor lead-lag motion with airframe on its landing gear; recovery is immediate liftoff or throttle reduction, so gear oleo pressures and dampers are airworthiness-critical.

Coning angle results from blade lift; flapping hinges or flexure relief of the root bending moment. Flap-back increases with speed and forward tilt, flap-forward occurs at low speed and high thrust.

Tail rotor types: conventional single tail rotor (pitch change via pitch-change spider and slider), Fenestron/fan-in-fin (ducted, more blades, quieter), and NOTAR (circulation control using main rotor downwash and a variable-pitch fan).

Primary structure on a helicopter includes the main gearbox deck/frame, keel beams, tail boom attachments and the mast support; secondary structure includes fairings, doors and cowlings that carry only aerodynamic or handling loads.

Blade tracking is checked by flag or electronic tracking; out-of-track blades cause 1-per-rev vibration. Blade balance is corrected by chordwise or spanwise weights, per the maintenance manual.

Composite airframe repairs: scarf or stepped repairs follow the SRM; wet layup vs prepreg, ply orientation and cure cycle are recorded; lightning protection mesh and bonding straps must be restored.

Corrosion-prone rotorcraft areas: battery compartment, gearbox/fuel tank sumps, landing gear oleos, exhaust and tail rotor drive shaft splines; use prescribed CPC and inspect per the corrosion control schedule.

Turboshaft engines are free-turbine (gas generator and power turbine on separate shafts, e.g. Arriel, RR300) or fixed-shaft (single shaft, e.g. Allison 250). Free-turbine design allows the rotor to be driven through a freewheel unit.

N1 is gas generator speed, N2 is power turbine/rotor speed. Engine limits are expressed as N1, N2, TOT (turbine outlet temperature) or T4/T5, torque (psi or %), and oil pressure; exceedances require a maintenance action per the engine manual.

Freewheel (sprag/one-way clutch) decouples the rotor from the engine during autorotation or engine failure; its function is checked during run-up and after any overspeed or hard landing.

The engine fuel control unit meters fuel using N1, compressor discharge pressure (Pc), TOT and collective pitch input; the hydro-mechanical unit is trimmed by the electronic control (EECU/FADEC), which also controls starting and overspeed protection.

Engine anti-ice uses hot compressor bleed to the intake; inlet barrier filters or particle separators protect the compressor from sand and FOD in dusty operations; both must be checked for blockage and correct operation.

Turboshaft starting sequence: starter cranks N1, ignition is energised, fuel is introduced at a defined N1, light-off TOT is monitored, starter cuts out at self-sustaining N1; a hot start (TOT limit exceeded) requires fuel shutoff and engine inspection.

Engine oil system: pressure pump, scavenge pump, filter with bypass and chip detector; gearbox chip detectors are checked for fuzz vs metal particles, and the magnetic plug is a scheduled inspection item.

Autorotation: main rotor is driven by airflow, the freewheel disengages the engine, and rotor RPM is controlled by collective; the engine-off check confirms the freewheel releases and the rotor turns freely.

DC systems on light helicopters use a 14 V or 28 V battery, engine-driven alternator or generator, voltage regulator, overvoltage protection and a split bus (battery bus, avionics bus).

Ammeter or loadmeter indications: a loadmeter shows alternator output, an ammeter shows battery charge/discharge; a discharge in flight indicates alternator failure and requires load shedding per the flight manual.

Bonding and static discharge: all major metallic components are bonded to a common ground; the tail rotor and rotor head have static discharge paths, and bonding resistance is checked per the maintenance manual.

Pitot-static system: pitot heat, static ports and drain traps; a blocked static source causes airspeed, altimeter and VSI errors, so alternate static source or the flight manual procedure applies.

Rotorcraft instruments: dual tachometer (N1/N2 or rotor RPM), torque gauge (turbine), TOT gauge, fuel quantity and flow, and a low rotor RPM horn or light. The low RPM horn is tested before flight.

Magnetic compass swing is required after installing or replacing electrical or magnetic equipment, after welding, or after a major structural change; deviation card is placarded in the cockpit.

Avionics installation: wire routing separated from power cables, shielded cables grounded at one end, circuit breakers correctly rated, and antenna VSWR checked after installation.

Emergency power: battery-only operation has a defined endurance; the emergency bus powers essential instruments and radios. Battery capacity check and emergency bus test are scheduled items.

EFIS/glass cockpit: display units are line-replaceable, require configuration/software part-number verification, and air data/attitude source selection must be verified during pre-flight checks.

CAA NZ rules: Part 43 (maintenance), Part 66 (licensing), Part 91/135/121 (operations), Part 145 (maintenance organisations). An AME licence is issued under Part 66 with type ratings; certification requires the correct rating and scope.

Maintenance release: after maintenance, a certificate of release to service (CRS) is issued by an appropriately rated LAME; the CRS states the work done, the references used and any limitations.

Maintenance records: logbook entries, work cards, defect reports and CRS copies are retained per Part 43/91 requirements; records must be legible, permanent and traceable to the task and the person.

Airworthiness directives are mandatory; service bulletins are usually recommended unless made mandatory by an AD or the operator's maintenance programme. The maintenance programme is approved by the CAA.

Human factors: the Dirty Dozen (fatigue, complacency, distraction, pressure, stress, lack of communication, lack of resources, lack of teamwork, lack of knowledge, lack of assertiveness, norms, awareness). Use the SHELL model and MEDA for occurrence analysis.

Error management: two-person independent inspection for critical tasks, torque wrench calibration records, tool control (shadow boards, tool counts), and FOD prevention.

Maintenance error reporting is non-punitive; the occurrence report goes to the CAA and the operator's safety management system (SMS) per Part 100/Part 12 requirements.

Shift handover must include open defects, deferred items (MEL/CDL), parts on order, and work in progress; verbal handover alone is not sufficient, it must be recorded.

Fuel and fluid handling: fuel samples are taken from sumps and drained until clear; Jet A-1 water contamination is detected by clear-and-bright test; refuelling requires bonding and grounding.

Main rotor head types: fully articulated (separate flap, lead-lag and pitch hinges), semi-rigid/teetering (two-blade, underslung flapping hinge), and rigid/hingeless (loads carried by flexing composite or elastomeric elements).

Lead-lag (drag) hinges or elastomeric dampers absorb in-plane Coriolis and acceleration forces; a failed damper produces ground resonance, so damper condition and bolt torque are mandatory inspection items.

Ground resonance is a self-exciting coupling of rotor lead-lag motion with airframe on its landing gear; recovery is immediate liftoff or throttle reduction, so gear oleo pressures and dampers are airworthiness-critical.

Coning angle results from blade lift; flapping hinges or flexure relief of the root bending moment. Flap-back increases with speed and forward tilt, flap-forward occurs at low speed and high thrust.

Tail rotor types: conventional single tail rotor (pitch change via pitch-change spider and slider), Fenestron/fan-in-fin (ducted, more blades, quieter), and NOTAR (circulation control using main rotor downwash and a variable-pitch fan).

Primary structure on a helicopter includes the main gearbox deck/frame, keel beams, tail boom attachments and the mast support; secondary structure includes fairings, doors and cowlings that carry only aerodynamic or handling loads.

Blade tracking is checked by flag or electronic tracking; out-of-track blades cause 1-per-rev vibration. Blade balance is corrected by chordwise or spanwise weights, per the maintenance manual.

Composite airframe repairs: scarf or stepped repairs follow the SRM; wet layup vs prepreg, ply orientation and cure cycle are recorded; lightning protection mesh and bonding straps must be restored.

Corrosion-prone rotorcraft areas: battery compartment, gearbox/fuel tank sumps, landing gear oleos, exhaust and tail rotor drive shaft splines; use prescribed CPC and inspect per the corrosion control schedule.

Turboshaft engines are free-turbine (gas generator and power turbine on separate shafts, e.g. Arriel, RR300) or fixed-shaft (single shaft, e.g. Allison 250). Free-turbine design allows the rotor to be driven through a freewheel unit.

N1 is gas generator speed, N2 is power turbine/rotor speed. Engine limits are expressed as N1, N2, TOT (turbine outlet temperature) or T4/T5, torque (psi or %), and oil pressure; exceedances require a maintenance action per the engine manual.

Freewheel (sprag/one-way clutch) decouples the rotor from the engine during autorotation or engine failure; its function is checked during run-up and after any overspeed or hard landing.

The engine fuel control unit meters fuel using N1, compressor discharge pressure (Pc), TOT and collective pitch input; the hydro-mechanical unit is trimmed by the electronic control (EECU/FADEC), which also controls starting and overspeed protection.

Engine anti-ice uses hot compressor bleed to the intake; inlet barrier filters or particle separators protect the compressor from sand and FOD in dusty operations; both must be checked for blockage and correct operation.

Turboshaft starting sequence: starter cranks N1, ignition is energised, fuel is introduced at a defined N1, light-off TOT is monitored, starter cuts out at self-sustaining N1; a hot start (TOT limit exceeded) requires fuel shutoff and engine inspection.

Engine oil system: pressure pump, scavenge pump, filter with bypass and chip detector; gearbox chip detectors are checked for fuzz vs metal particles, and the magnetic plug is a scheduled inspection item.

Autorotation: main rotor is driven by airflow, the freewheel disengages the engine, and rotor RPM is controlled by collective; the engine-off check confirms the freewheel releases and the rotor turns freely.

DC systems on light helicopters use a 14 V or 28 V battery, engine-driven alternator or generator, voltage regulator, overvoltage protection and a split bus (battery bus, avionics bus).

Ammeter or loadmeter indications: a loadmeter shows alternator output, an ammeter shows battery charge/discharge; a discharge in flight indicates alternator failure and requires load shedding per the flight manual.

Bonding and static discharge: all major metallic components are bonded to a common ground; the tail rotor and rotor head have static discharge paths, and bonding resistance is checked per the maintenance manual.

Pitot-static system: pitot heat, static ports and drain traps; a blocked static source causes airspeed, altimeter and VSI errors, so alternate static source or the flight manual procedure applies.

Rotorcraft instruments: dual tachometer (N1/N2 or rotor RPM), torque gauge (turbine), TOT gauge, fuel quantity and flow, and a low rotor RPM horn or light. The low RPM horn is tested before flight.

Magnetic compass swing is required after installing or replacing electrical or magnetic equipment, after welding, or after a major structural change; deviation card is placarded in the cockpit.

Avionics installation: wire routing separated from power cables, shielded cables grounded at one end, circuit breakers correctly rated, and antenna VSWR checked after installation.

Emergency power: battery-only operation has a defined endurance; the emergency bus powers essential instruments and radios. Battery capacity check and emergency bus test are scheduled items.

EFIS/glass cockpit: display units are line-replaceable, require configuration/software part-number verification, and air data/attitude source selection must be verified during pre-flight checks.

CAA NZ rules: Part 43 (maintenance), Part 66 (licensing), Part 91/135/121 (operations), Part 145 (maintenance organisations). An AME licence is issued under Part 66 with type ratings; certification requires the correct rating and scope.

Maintenance release: after maintenance, a certificate of release to service (CRS) is issued by an appropriately rated LAME; the CRS states the work done, the references used and any limitations.

Maintenance records: logbook entries, work cards, defect reports and CRS copies are retained per Part 43/91 requirements; records must be legible, permanent and traceable to the task and the person.

Airworthiness directives are mandatory; service bulletins are usually recommended unless made mandatory by an AD or the operator's maintenance programme. The maintenance programme is approved by the CAA.

Human factors: the Dirty Dozen (fatigue, complacency, distraction, pressure, stress, lack of communication, lack of resources, lack of teamwork, lack of knowledge, lack of assertiveness, norms, awareness). Use the SHELL model and MEDA for occurrence analysis.

Error management: two-person independent inspection for critical tasks, torque wrench calibration records, tool control (shadow boards, tool counts), and FOD prevention.

Maintenance error reporting is non-punitive; the occurrence report goes to the CAA and the operator's safety management system (SMS) per Part 100/Part 12 requirements.

Shift handover must include open defects, deferred items (MEL/CDL), parts on order, and work in progress; verbal handover alone is not sufficient, it must be recorded.

Fuel and fluid handling: fuel samples are taken from sumps and drained until clear; Jet A-1 water contamination is detected by clear-and-bright test; refuelling requires bonding and grounding.