Module 13: Aircraft Aerodynamics, Structures and Systems

13.1Theory of Flight

13.1(a)Aeroplane Aerodynamics and Flight Controls

• Atmosphere: composition, International Standard Atmosphere (ISA)
• Bernoulli's theorem, subsonic airflow
• Boundary layer: laminar and turbulent flow
• Generation of lift: angle of attack, lift coefficient, aerofoil types
• Drag: parasite drag, induced drag, lift/drag ratio
• Stalling: stall angle, stall speed, stall warning
• Aerofoil contamination effects (ice, frost, rain)
• Stability: static and dynamic, longitudinal, lateral, directional
• Primary flight controls: ailerons, elevators, rudder
• Secondary controls: trim tabs, flaps, slats, spoilers, speed brakes
• High speed flight: speed of sound, Mach number, compressibility effects

13.1(b)Rotary Wing Aerodynamics

• Terminology: rotor disc, tip path plane, advancing/retreating blade
• Principles of rotary wing flight
• Torque reaction and directional control
• Gyroscopic precession
• Dissymmetry of lift and blade flapping
• Ground effect and translational lift
• Autorotation principles
• Hovering, forward flight, climbing, descending

13.2Structures — General Concepts (ATA 51)

13.2(a)General Concept

• Fuselage, wings, stabilisers: structural members and functions
• Structural classification: primary, secondary, tertiary
• Fail-safe, safe-life, damage-tolerant design concepts
• Aircraft zoning and station identification systems
• Stress, strain, bending, compression, shear, torsion, fatigue
• Lightning strike protection and bonding

13.2(b)Fundamentals of Structural Systems

• Construction methods: riveted, bonded, composite
• Doors: types, construction, safety devices
• Windows and windshields: construction, heating, bird-strike resistance
• Wing construction: spars, ribs, stringers, skin
• Stabiliser construction
• Nacelle and pylon construction
• Helicopter structural features: fuselage, tailboom, transmission deck

13.3Autoflight (ATA 22)

13.3(a)Fundamentals of Automatic Flight Control

• Autopilot system fundamentals: sensing, computing, output
• Autopilot modes: heading hold, altitude hold, vertical speed, LNAV, VNAV
• Flight director: command bars, modes, operation
• Yaw damper systems
• Automatic trim
• Autopilot interlocks and disconnect systems
• Servomotors and actuators: electric, hydraulic
• Autopilot BITE and monitoring
• Helicopter autopilot and stability augmentation systems (SAS)
• Automatic stabilisation equipment (ASE)

13.3(b)Autothrottle and Automatic Landing Systems

• Autothrottle: principles, speed and thrust modes
• Approach mode: ILS coupling, glideslope/localiser tracking
• Autoland systems: fail-passive, fail-operational
• CAT I, CAT II, CAT III approach requirements
• Go-around mode
• Autoland alerting and monitoring systems
• Wind shear detection and recovery

13.4Communication/Navigation (ATA 23/34)

13.4(a)Fundamentals of Communication and Navigation Systems

• VHF communication: principles, operation, frequency range
• HF communication: principles, operation, SSB
• SATCOM: satellite communication systems
• Intercom and passenger address systems
• Audio integrating systems and audio control panels
• Emergency communication: ELT operation and types
• CVR (Cockpit Voice Recorder)
• VOR: principles of operation, types (DVOR, CVOR)
• ILS: localiser, glideslope, marker beacons, operation
• ADF/NDB: principles, loop and sense aerials, operation
• DME: principles, operation, frequency pairing with VOR/ILS
• GPS/GNSS: principles, satellite constellations, RAIM, SBAS, GBAS
• RNAV and FMS: area navigation, waypoints, flight management system
• Inertial navigation systems (INS/IRS): principles, laser ring gyro, fibre optic gyro
• Weather radar: principles, modes, operation
• Radio altimeter: principles, operation

13.4(b)Fundamentals of Aircraft Surveillance Systems

• Transponder: Mode A, Mode C, Mode S, operation
• ADS-B: Automatic Dependent Surveillance — Broadcast
• TCAS/ACAS: Traffic Collision Avoidance System — principles, RA/TA advisories
• TAWS/EGPWS: Terrain Awareness Warning System — modes, operation
• Secondary Surveillance Radar (SSR)
• Multilateration

13.5Electrical Power (ATA 24)

• Batteries: types (lead-acid, NiCd, Li-ion), installation, operation, maintenance
• DC generation: generators, starter-generators
• AC generation: alternators, constant-frequency and frequency-wild systems
• Integrated Drive Generators (IDGs)
• Transformer Rectifier Units (TRUs) and inverters
• Emergency generation: RAT (Ram Air Turbine)
• Power distribution: bus systems, essential bus, battery bus, split bus
• Circuit protection: circuit breakers, fuses, current limiters
• External/ground power connections and interlocks
• Load management and shedding
• Voltage regulation and current limiting
• Electrical system monitoring and BITE
• Power quality and harmonic distortion

13.6Equipment and Furnishings (ATA 25)

• Emergency equipment: oxygen masks, life vests, life rafts, slides
• Emergency exits and escape systems
• Seat construction, seat belts, harnesses
• Cabin interior: panels, overhead bins, partitions
• Galley and lavatory installations
• Cargo compartments: liners, nets, restraints
• Cargo loading systems and ball mats
• ELT (Emergency Locator Transmitter)
• Portable fire extinguishers and crash axes

13.7Flight Controls (ATA 27/67)

13.7(a)Primary and Secondary Flight Controls (ATA 27)

• Ailerons, elevators, rudder: operation and function
• Spoilers: flight spoilers, ground spoilers
• Trim systems: trim tabs, trimmable horizontal stabiliser, electric trim
• Flaps: types (plain, split, slotted, Fowler), operation
• Slats and leading edge devices
• Speed brakes and lift dumpers

13.7(b)Actuation and Protection

• Manual control: cables, rods, bellcranks, pulleys, torque tubes
• Hydraulic actuators: linear, rotary
• Electrical actuators
• Fly-by-wire (FBW) systems: principles, redundancy, flight control laws
• Artificial feel and Q-feel systems
• Stall protection: stick shaker, stick pusher
• Mach trim systems
• Yaw damper and rudder limiter

13.7(c)System Operation

• Control system architecture and redundancy
• Power control units (PCUs)
• Autopilot servo integration
• Flap and slat asymmetry protection
• Control surface monitoring and BITE
• Gust lock systems

13.7(d)Rotorcraft Flight Controls (ATA 67)

• Swashplate assembly: rotating and non-rotating stars
• Collective pitch control system
• Cyclic pitch control system
• Tail rotor / yaw control system
• Mixing unit and control rods
• Servo and hydraulic boost units
• Stability augmentation systems (SAS)
• Fly-by-wire helicopter applications

13.8Instruments (ATA 31)

• Pitot-static systems: pitot tube, static ports, alternate static
• Airspeed indicator (ASI): IAS, CAS, TAS, Mach
• Altimeter: operation, subscale settings, encoding altimeter
• Vertical speed indicator (VSI, IVSI)
• Gyroscopic instruments: attitude indicator, heading indicator, turn coordinator
• Compass systems: direct reading, remote reading (flux valve)
• Engine instruments: RPM, temperature (EGT, CHT, TGT), pressure, fuel flow, torque
• Glass cockpit: EFIS, EICAS/ECAM, PFD, MFD, synoptic displays
• Standby instruments and switching
• Air data computers (ADC) and air data inertial reference units (ADIRU)
• Alerting/warning systems: master caution, master warning, annunciator panels
• Stall warning systems and angle-of-attack indicators
• Flight recorders: FDR and CVR — principles and mandatory parameters

13.9Lights (ATA 33)

• External lights: navigation (red, green, white), anti-collision (beacon, strobe), landing, taxi, runway turnoff, wing inspection, logo
• Internal lights: cockpit, cabin, cargo, emergency
• Emergency lighting: floor path, exit signs, battery-powered
• Light control systems: switching, dimming, automatic activation
• NVG-compatible lighting (where applicable)

13.10On-Board Maintenance Systems (ATA 45)

• Central maintenance computers (CMC)
• Built-in test equipment (BITE): power-up, continuous, initiated
• Centralised fault display system (CFDS)
• Troubleshooting and fault isolation using BITE
• Data loading systems: databases, software updates
• Maintenance data recording and retrieval
• Electronic logbook systems
• Maintenance access terminals

13.11Air Conditioning and Cabin Pressurisation (ATA 21)

13.11(a)Pressurisation

• Pressurisation systems: need, principles, operation
• Cabin pressure controllers, outflow valves, safety valves
• Pressure differential, maximum differential
• Cabin altitude and rate control

13.11(b)Air Supply

• Air supply sources: engine bleed, APU bleed, pneumatic ground supply
• Flow control and shut-off valves
• Cross bleed systems

13.11(c)Air Conditioning

• Air cycle machines (bootstrap, reverse bootstrap)
• Vapour cycle systems
• Temperature control and distribution systems
• Recirculation fans and filters

13.11(d)Safety and Warning Devices

• Cabin altitude warning systems
• Over-pressure and negative pressure relief
• Duct overheat detection
• Excessive cabin rate of change warnings

13.12Fire Protection (ATA 26)

13.12(a)Fire and Smoke Detection and Extinguishing Systems

• Fire detection: thermocouple, resistance loop, continuous loop (pneumatic, electrical)
• Smoke detection: ionisation, photoelectric
• Fire zones: engine, APU, cargo, wheel well, lavatory
• Fixed fire extinguishing: HRD bottles, agents (Halon alternatives, inert gas)
• Fire shut-off valves and fire switches
• System testing and maintenance

13.12(b)Portable Fire Extinguisher

• Types: water, CO₂, dry chemical, Halon/clean agent
• Fire class selection (A, B, C, D)
• Inspection and maintenance requirements

13.13Fuel Systems (ATA 28, ATA 47)

13.13(a)System Layout

• Tank types: integral, bladder, rigid removable
• Tank locations: wing, centre section, fuselage, auxiliary, trim tanks
• Tank venting and pressurisation
• Baffles and anti-surge provisions

13.13(b)Fuel Handling

• Boost pumps: AC motor-driven, DC, jet pump (ejector)
• Transfer and crossfeed systems
• Refuelling: overwing, pressure (single-point)
• Defuelling and fuel jettison systems
• Fuel heating and filtration

13.13(c)Indications and Warnings

• Fuel quantity indication: capacitance type, drip sticks
• Fuel flow measurement
• Fuel temperature indication
• Low level and low pressure warnings

13.13(d)Special Systems

• Fuel jettison (dump) systems
• Inert gas generation systems (OBIGGS)
• Auxiliary and ferry tank systems

13.13(e)Balancing

• CG management through fuel transfer
• Automatic fuel sequencing and scheduling
• Trim tank operation

13.14Hydraulic Power (ATA 29)

13.14(a)System Layout

• Hydraulic system architecture
• Fluids: types (mineral, synthetic, phosphate-ester), properties
• Reservoirs: types, pressurisation, level indication
• Accumulators: types, pre-charge, functions

13.14(b)System Operation (1)

• Pumps: engine-driven, electric motor-driven, hand pumps
• Pressure regulation and relief valves
• Filters and filter bypass indicators
• Actuators: linear, rotary
• Seals and gaskets

13.14(c)System Operation (2)

• Power transfer units (PTUs)
• Ram air turbine (RAT) hydraulic power
• System monitoring: pressure, temperature, quantity
• Leak classification
• Multiple system architecture and redundancy

13.15Ice and Rain Protection (ATA 30)

13.15(a)Principles

• Ice formation: conditions, types (rime, glaze, mixed)
• Effects of icing on performance and systems
• Ice detection systems

13.15(b)De-icing

• Pneumatic de-icing boots
• Electro-thermal de-icing
• Windshield de-icing

13.15(c)Anti-icing

• Hot air anti-icing: engine bleed systems
• Electro-thermal anti-icing
• Fluid (TKS) anti-icing systems

13.15(d)Wiper Systems

• Windshield wiper systems

13.15(e)Rain Repellent

• Chemical rain repellent systems
• Hydrophobic coatings

13.16Landing Gear (ATA 32)

13.16(a)Description

• Landing gear types and configurations
• Shock absorbers: oleo-pneumatic, spring, rubber
• Tyres: construction, ply rating, speed rating, creep marks
• Wheels: construction, bearings, fusible plugs
• Brakes: disc, multi-disc, carbon
• Anti-skid and autobrake systems
• Nose wheel steering systems

13.16(b)System

• Extension and retraction: hydraulic, electric
• Uplocks, downlocks, overcenter mechanisms
• Gear doors and sequencing
• Warning systems
• Emergency extension systems

13.16(c)Air-Ground Sensing

• Weight-on-wheels (WOW) switches
• Squat switch functions: ground spoilers, brakes, thrust reversers, pressurisation

13.17Oxygen (ATA 35)

• Oxygen system requirements
• Sources: gaseous (high-pressure), liquid, chemical generators
• Crew oxygen: diluter-demand, pressure-demand masks
• Passenger oxygen: continuous flow, chemical generators, drop-out systems
• Portable oxygen bottles
• System components: regulators, valves, distribution, indicators
• System safety: servicing, contamination, fire hazards

13.18Pneumatic/Vacuum (ATA 36)

• Pneumatic system layout and sources
• System components: valves, regulators, filters
• Pneumatic system applications: engine starting, de-icing, door seals
• Vacuum pump systems and instruments

13.19Water/Waste (ATA 38)

• Potable water system: tanks, pumps, distribution, heaters
• Waste and toilet systems: vacuum waste, chemical waste
• Drain mast heaters
• Servicing connections and procedures

13.20Integrated Modular Avionics (ATA 42)

13.20(a)Overall System Description and Theory

• IMA concept and architecture
• Common computing resources
• ARINC 653 partitioning
• Advantages over federated avionics

13.20(b)Typical System Layouts

• Core processing and I/O modules
• Line Replaceable Modules (LRMs)
• Data buses: ARINC 429, ARINC 664/AFDX
• IMA configuration and software loading

13.21Cabin Systems (ATA 44)

• Cabin management systems
• In-flight entertainment (IFE) systems
• Passenger communications
• Cabin lighting control
• Cabin monitoring systems

13.22Information Systems (ATA 46)

• ACARS (Aircraft Communications Addressing and Reporting System)
• Data network systems: Ethernet, AFDX, wireless LAN
• Electronic Flight Bag (EFB)
• Software configuration management
• Database loading and management