CPL AGK / Systems study guide
CPL AGK / Systems · Work through your exam, one topic at a time.
Aircraft General Knowledge - Systems is the technical paper of the Commercial Pilot Licence knowledge examination. It tests whether a candidate understands how an aeroplane's airframe, powerplant and supporting systems actually work, and what happens when they fail, rather than whether they can recite a component list. The CPL AGK / Systems study guide has 11 sections and about 3,173 words.
01Airframe, Structure and Flight Control Actuation
Candidates must be able to describe the primary structure and how loads travel through it. The fuselage is a semi-monocoque shell: skin carries shear and hoop stress, stringers and frames stiffen it against buckling, and a few bulkheads pick up concentrated loads (wing attachment, pressure bulkheads, engine mounts).
346 words, about 2 min02Hydraulic Systems: Components and Monitoring
Typical transport aircraft use two or three independent systems, each with its own reservoir, engine-driven pump, and often an electric pump, a power transfer unit (PTU) or ram air turbine (RAT) for backup. Reservoirs are pressurised (by bleed air or hydraulic pressure) to prevent cavitation at altitude and to feed the pumps; they contain standpipes so that a leak in one user circuit does not drain the whole reservoir.
316 words, about 2 min03Pneumatic, Bleed Air and Pressurisation Systems
Bleed air is taken from engine compressor stages (low and high pressure ports, with a pressure-regulating and shut-off valve), from the APU, or from a ground cart. It supplies air-conditioning packs, pressurisation, engine and wing anti-icing, hydraulic reservoir pressurisation, and engine starting.
295 words, about 1 min04Electrical Generation, Distribution and Protection
Light aircraft typically use a 14 V or 28 V DC system with an engine-driven alternator or generator, a voltage regulator, a battery and a bus bar. Transports use 115 V 400 Hz AC from integrated drive generators (IDGs) or variable-frequency generators, plus transformer-rectifier units (TRUs) for DC, and a battery for essential DC and emergency supply.
300 words, about 2 min05Fuel Storage, Feed, Transfer and Gauging
Fuel is carried in wing tanks (integral structure), fuselage tanks, or tip tanks, and in transports often in centre and outer wing tanks. Feed is normally from the tank serving the engine on that side, via boost pumps, with a cross-feed valve for balancing or for feeding both engines from one side.
302 words, about 2 min06Powerplant Installation, Lubrication, Ignition, Starting and Propellers
Know the engine installation: mounts and firewalls, cowling and cooling, induction and exhaust, fuel control unit, and the accessories driven by the engine (vacuum pump, alternator, hydraulic pump). Lubrication uses a dry-sump system with a pressure pump, scavenge pump, oil cooler, filter and bypass valve; oil pressure and temperature are the key indications, and low pressure with normal temperature is a different diagnosis from high temperature with normal pressure.
293 words, about 1 min07Ice, Rain and Environmental Protection
Anti-icing prevents ice formation (thermal bleed air on wings and engine inlets, electrical heater mats on small aircraft); de-icing removes ice already formed (pneumatic boots, weeping alcohol). Know which surfaces are protected: wing leading edges, tail leading edges (sometimes not protected - a trap), propeller blades, engine intakes, pitot heads, static ports, and windscreens.
247 words, about 1 min08Landing Gear, Wheels, Brakes, Antiskid and Tyres
Gear is extended and retracted by hydraulic or electric actuators, with uplocks and downlocks, and a sequence valve or control unit. Emergency extension may be by gravity, nitrogen bottle or manual crank.
302 words, about 2 min09Instruments, Indications and Warning Systems
Pitot/static instruments are the airspeed indicator, altimeter and vertical speed indicator. Know the errors: position error, instrument error, and the behaviour with blocked pitot or static.
253 words, about 1 min10Oxygen, Fire Protection and Emergency Equipment
Know the difference between a continuous-flow system (mask with rebreather bag, used in light aircraft) and a demand system (transport aircraft, with diluter-demand masks and a regulator). Oxygen is stored as high-pressure gas (typically 1,800-2,000 psi in light aircraft cylinders), as liquid oxygen, or generated by a chemical or molecular sieve system.
276 words, about 1 min11Automatic Flight Control, Avionics and Navigation Architecture
Know the components: autopilot computer, servos or actuators, mode control panel, and the sensors (ADC, AHRS/IRU, radio altimeter). Modes include heading, altitude hold, vertical speed, ILS approach, and autothrottle.
243 words, about 1 min