CAA NZ AME Aeroplanes 1 (Subject 4) common mistakes
CAA NZ AME Aeroplanes 1 (Subject 4) · Understand the traps and how to avoid them.
When asked to identify which structural component carries the primary flight loads in a semi-monocoque wing, candidates name the skin alone and ignore the spar caps and stringers, or they confuse a spar web (carries shear) with a spar cap (carries bending).
Semi-monocoque construction is taught as 'stressed skin', so candidates latch onto the skin as the answer and lose the load-path distinction between bending, shear and torsion members. The failure mode is a load-path reasoning gap, not a memory gap.
What to do instead
Practise drawing a wing box and labelling each member with the load it carries: spar caps take bending, webs take shear, skin and stringers take torsion and compression buckling, ribs maintain shape and transfer loads. Answer load-path questions by tracing the load from attachment to reaction, not by naming the biggest visible part.
On hydraulic system questions, candidates state that a typical transport aeroplane has a single hydraulic system, or they mislabel which system powers which user (e.g. saying the green system drives the standby gear extension) instead of recognising the multi-system redundancy architecture.
Systems are revised in isolation, so the candidate remembers component names but not the allocation map across systems A, B and standby (or green, blue, yellow). Under time pressure they guess an allocation rather than reason from redundancy philosophy.
What to do instead
Build a one-page allocation matrix for the aircraft type studied: system, pressure, fluid, pumps, reservoirs, users, and what happens if it is lost. Learn the redundancy logic (why the standby system exists, what it powers, how it is isolated) rather than memorising isolated facts.
Candidates answer fuel system questions by describing the boost pumps as pressure pumps that supply the engines directly, missing that on many types the engine-driven pump is the primary supply and the boost pump provides positive feed pressure and vapour suppression, and they cannot explain crossfeed or fuel transfer logic.
Pump terminology overlaps and the candidate conflates 'boost' with 'main supply'. Diagrams showing pump symbols without functional annotation reinforce the error.
What to do instead
For each pump in the system, state its type, drive, location, normal function, and the condition under which it becomes critical (engine start, high altitude, crossfeed, tank transfer). Answer with the function first, then the pump name.
When asked about ice protection, candidates say the wing anti-ice system uses bleed air on all aeroplanes, or they cannot distinguish anti-ice (prevent formation) from de-ice (remove after formation), and they omit that some surfaces use electrical heating or weeping fluid.
Textbook generalisations are applied to every type. The candidate has not separated the two functions linguistically, so the terminology collapses in the answer.
What to do instead
Fix the definitions first: anti-ice prevents, de-ice removes. Then tabulate surface by surface (wing leading edge, tail, engine inlet, pitot, static, windshield) with the method used and the source of energy. Learn one type's system in detail and note where other types differ.
On electrical power questions, candidates confuse the role of the battery and the generator/alternator, claiming the battery powers the main bus in normal flight, or they cannot explain what happens when a generator trips and the bus tie closes.
The candidate memorises component names but not the normal/abnormal/emergency state transitions. Distribution logic is spatial and is poorly retained from text-only revision.
What to do instead
Draw the distribution schematic from memory: source, bus, tie, essential bus, and the state change on each failure. Rehearse three scenarios aloud (normal, one generator lost, both lost) and name what remains powered in each.
Candidates describe a flight instrument error as a fixed offset, e.g. saying pitot-static blockage causes a constant altitude error, instead of tracing how a blocked pitot or static port makes the instrument behave like an altimeter or airspeed indicator respectively as the aircraft climbs or descends.
The candidate learns the instrument's normal principle but never rehearses the failure case dynamically. They answer with a static fact when the question requires reasoning about a changing pressure.
What to do instead
For each blockage case, reason step by step: which pressure is trapped, which is still connected, and what the instrument will read as the aircraft climbs or descends. Write the four cases (pitot blocked, static blocked, both blocked, leak) as short scenarios and predict the indications.
In flight controls, candidates say the ailerons control yaw or that the rudder provides roll, or they cannot explain why a jammed control surface requires a specific alternate control strategy or why a split elevator or asymmetric flap causes a roll and pitch couple.
Primary and secondary effects of controls are learned as single facts without the coupled behaviour, and asymmetric failures are rarely practised as reasoning problems.
What to do instead
Learn each control's primary effect, secondary effect and adverse effect, then work through asymmetric failure cases: what force or moment is produced, what the pilot has available, and what the aircraft does if nothing is done.
On landing gear questions, candidates claim the downlock is achieved by hydraulic pressure alone, or they cannot describe the sequence of gear extension including uplocks, hydraulic release, free-fall, and the role of the squat switch and warning system.
The candidate remembers the actuator but not the locking and indication chain. Sequence questions expose the gap because they require ordering, not recall of a single part.
What to do instead
Learn the gear cycle as an ordered sequence with the mechanism at each step: unlock, actuate, downlock, indicate, and the independent backup. Then learn the safety interlocks (squat switch, gear warning, retraction inhibit) and why each exists.
On powerplant installation questions, candidates confuse the function of the engine fire detection and extinguishing system with the APU system, or they cannot explain what a firewall shutoff valve isolates and when it closes, and they misdescribe propeller feathering as simply stopping rotation rather than minimising drag and windmilling.
System boundaries blur because the candidate studies each system in isolation and never maps the interface points between engine, APU, fuel, hydraulic and electrical systems.
What to do instead
Learn the installation as an interface diagram: what passes through the firewall, what the shutoff valves control, which systems have independent detection, and the purpose of feathering (drag reduction, windmilling prevention, damage limitation). Answer interface questions by naming both sides of the boundary.
In maintenance and airworthiness questions, candidates answer with what a task does rather than who may certify it and on what basis, e.g. confusing a scheduled inspection with an airworthiness directive, or stating that any licensed engineer can release any aircraft without regard to type rating, approval and the maintenance programme.
Technical knowledge is revised heavily while regulatory and certification content is skimmed, so the candidate substitutes practical plausibility for the actual rule.
What to do instead
Separate the concepts explicitly: maintenance programme vs AD vs service bulletin vs defect report, and task performance vs certification and release. For each, learn who authorises it, who performs it, who certifies it, and what record results. Practise short scenario questions where the answer hinges on authorisation, not on the physical task.