Airframe Systems and Components
Structures and systems
Candidates must understand the airframe as load paths and as systems. On structure: primary, secondary and tertiary structure; fail-safe, safe-life and damage-tolerance philosophies; corrosion types (galvanic, exfoliation, stress, fretting) and where they appear (battery compartments, lavatory floors, wing spar lower caps). On systems: flight controls (cables, push-pull rods, hydraulically powered surfaces, fly-by-wire with reversion modes), hydraulic systems (reservoirs, pumps, accumulators, priority valves, relief valves), pneumatic systems (bleed sources, precoolers, pressure regulation), pressurisation (outflow valve, cabin pressure controller, differential pressure limits) and ice/rain protection (thermal anti-ice, weeping wing, boots, windshield heat).
Traps
Questions test sequence and consequence: what happens when a hydraulic pump fails or a priority valve closes; which valve controls cabin altitude versus differential pressure; why a relief valve protects a system rather than the component. Distinguish anti-ice (preventive, usually heated leading edges) from de-ice (removal, usually boots). Distinguish fail-safe (structure tolerates failure until inspection) from safe-life (component retired before predicted failure).
Worked example
A question asks which component limits cabin differential pressure. Reason: the outflow valve modulates cabin pressure, the controller commands it, and the negative pressure relief and positive pressure relief valves protect structure. The answer is the relief valve, not the outflow valve, when the question says "protects the structure".
Rule of thumb
Map every system to source, control, actuator, protection, indication - five boxes. Most distractors swap one box.