✈️Intro to Flight Unit 14 – Aircraft Systems & Instruments

Key Aircraft Systems

• Electrical system provides power for avionics, lighting, and other electrical components
  • Consists of batteries, generators, and alternators
  • Distributes power through wiring and circuit breakers
• Hydraulic system uses pressurized fluid to operate landing gear, brakes, and control surfaces
  • Pumps, reservoirs, and actuators are main components
  • Provides high power with minimal weight
• Fuel system stores and delivers fuel to the engines
  • Includes fuel tanks, pumps, lines, and gauges
  • Ensures proper fuel flow and management
• Environmental control system regulates cabin temperature, pressure, and air quality
  • Utilizes bleed air from the engines or separate compressors
  • Maintains comfortable conditions for passengers and crew
• Ice and rain protection systems prevent ice accumulation and improve visibility
  • Includes anti-icing and de-icing equipment (heated surfaces, pneumatic boots)
  • Ensures safe operation in adverse weather conditions
• Landing gear system supports the aircraft during takeoff, landing, and ground operations
  • Consists of wheels, brakes, and shock absorbers
  • Retractable gear reduces drag during flight

Flight Instruments and Their Functions

• Airspeed indicator displays the aircraft's speed relative to the surrounding air
  • Measures dynamic pressure using a pitot-static system
  • Helps pilots maintain appropriate speeds for various phases of flight
• Altimeter shows the aircraft's altitude above a reference level (usually sea level)
  • Uses static pressure to determine altitude
  • Essential for maintaining proper vertical separation and terrain clearance
• Vertical speed indicator (VSI) displays the rate of climb or descent
  • Measures the rate of change in static pressure
  • Assists pilots in maintaining desired climb or descent rates
• Attitude indicator (artificial horizon) shows the aircraft's pitch and roll relative to the horizon
  • Gyroscopically stabilized to provide a stable reference
  • Critical for maintaining spatial orientation, especially in low visibility conditions
• Heading indicator displays the aircraft's magnetic heading
  • Gyroscopically stabilized and periodically adjusted to the magnetic compass
  • Used for navigation and maintaining desired course
• Turn coordinator indicates the rate and direction of turn, as well as slip or skid
  • Combines information from the rate gyro and inclinometer
  • Helps pilots maintain coordinated turns and detect imbalances
• Magnetic compass provides a basic reference for magnetic heading
  • Affected by aircraft acceleration, deceleration, and turning
  • Used to align the heading indicator and as a backup navigation tool

Navigation Systems

• VOR (VHF Omnidirectional Range) provides bearing information to or from a ground station
  • Pilots select a radial and fly along or intercept it
  • Forms the backbone of the low-altitude airway system
• DME (Distance Measuring Equipment) measures the slant range distance between the aircraft and a ground station
  • Paired with VOR for distance and bearing information
  • Helps pilots determine their position and estimate time to the station
• ILS (Instrument Landing System) provides precision guidance for landing in low visibility conditions
  • Consists of a localizer for lateral guidance and a glideslope for vertical guidance
  • Markers or DME provide distance information along the approach path
• GPS (Global Positioning System) uses satellite signals to determine the aircraft's position, speed, and track
  • Provides worldwide coverage and high accuracy
  • Enables direct point-to-point navigation and non-precision approaches
• ADF (Automatic Direction Finder) receives signals from non-directional beacons (NDBs)
  • Indicates the relative bearing to the NDB
  • Used for navigation and instrument approaches at some airports
• FMS (Flight Management System) integrates various navigation sensors and databases
  • Allows for automated navigation, performance optimization, and flight planning
  • Reduces pilot workload and improves efficiency

Communication Equipment

• VHF radio is the primary means of voice communication between pilots and air traffic control
  • Operates in the 118-137 MHz frequency range
  • Used for clearances, instructions, and pilot reports
• HF radio allows for long-range communication, especially over oceans and remote areas
  • Operates in the 3-30 MHz frequency range
  • Subject to atmospheric conditions and solar activity
• ELT (Emergency Locator Transmitter) activates automatically in the event of a crash
  • Transmits a distress signal on 406 MHz to alert search and rescue services
  • Helps locate the aircraft and survivors
• Transponder responds to interrogations from ground-based radar and provides aircraft identification and altitude information
  • Modes A, C, and S are commonly used
  • Essential for air traffic control surveillance and collision avoidance
• ACARS (Aircraft Communications Addressing and Reporting System) enables digital data communication between the aircraft and ground stations
  • Used for weather updates, flight plan changes, and maintenance reporting
  • Reduces the need for voice communication and improves efficiency
• Intercom allows for communication among the flight crew and with passengers
  • Facilitates coordination and information sharing
  • Can be integrated with the aircraft's audio panel for radio and navigation audio

Power Plants and Propulsion

• Reciprocating engines convert the linear motion of pistons into rotational motion to drive a propeller
  • Commonly used in small general aviation aircraft
  • Requires a mixture of fuel and air, ignited by spark plugs
• Turboprop engines use a gas turbine to drive a propeller
  • Provides higher power and efficiency compared to reciprocating engines
  • Suitable for short to medium-range aircraft and regional airliners
• Turbojet engines produce thrust by accelerating a large volume of air through a combustion chamber and exhaust nozzle
  • Simple design with few moving parts
  • Used in early jet aircraft and some military applications
• Turbofan engines add a large fan in front of the core engine to generate additional thrust
  • Majority of the air bypasses the core engine, improving efficiency and reducing noise
  • Powers most modern commercial airliners and business jets
• Ramjet engines rely on forward motion to compress incoming air, without the need for a compressor
  • Operates efficiently at high supersonic speeds
  • Used in some missiles and experimental aircraft
• Electric propulsion systems use electric motors powered by batteries or fuel cells
  • Produce zero emissions and have lower noise levels
  • Currently limited by battery technology, but show promise for future aircraft designs

Aircraft Control Surfaces

• Ailerons control roll by differentially changing the lift on the wings
  • Located near the wingtips and move in opposite directions
  • Banking the aircraft for turning and maintaining lateral balance
• Elevators control pitch by changing the lift on the horizontal stabilizer
  • Attached to the rear of the horizontal stabilizer
  • Raising or lowering the nose to climb, descend, or maintain level flight
• Rudder controls yaw by changing the side force on the vertical stabilizer
  • Hinged to the rear of the vertical stabilizer
  • Coordinates turns and counteracts adverse yaw
• Flaps increase lift and drag by changing the wing's camber and area
  • Deployed during takeoff and landing to reduce stall speed
  • Allow for slower approach speeds and shorter runway requirements
• Spoilers disrupt airflow over the wing, reducing lift and increasing drag
  • Used for roll control, speed braking, and landing ground spoilers
  • Can be deployed symmetrically or asymmetrically
• Trim tabs fine-tune the control surface positions to reduce pilot input forces
  • Attached to the trailing edges of the primary control surfaces
  • Adjust for changes in speed, weight, and center of gravity
• Slats extend from the leading edge of the wing to increase lift at high angles of attack
  • Delay flow separation and improve low-speed handling
  • Often used in conjunction with flaps during takeoff and landing

Safety Systems and Emergency Equipment

• Seat belts and shoulder harnesses restrain occupants during turbulence, maneuvering, and emergency landings
  • Prevent injuries from impact forces and loose objects
  • Some aircraft also have airbags for additional protection
• Life jackets provide flotation in the event of a water landing
  • Stowed under or near the seats, with instructions for use
  • Equipped with inflation tubes, whistles, and lights for visibility
• Life rafts accommodate passengers and crew in the event of a water evacuation
  • Stored in overhead compartments or external pods
  • Deployed and inflated automatically or manually
• Oxygen systems supply breathable air in the event of a cabin depressurization
  • Masks deploy automatically from overhead panels
  • Portable oxygen bottles are available for crew use
• Fire extinguishers are strategically located throughout the aircraft
  • Designed for use on specific types of fires (electrical, flammable liquids, etc.)
  • Operated by pulling a pin and squeezing the handle
• Evacuation slides allow for rapid egress from the aircraft in an emergency
  • Deploy and inflate automatically when the doors are opened in armed mode
  • Can be detached and used as life rafts in a water evacuation
• Emergency lighting guides passengers and crew to exits in low visibility conditions
  • Includes floor-level lighting, exit signs, and exterior lights
  • Powered by independent batteries or generators

Advanced Avionics and Automation

• Glass cockpit displays replace traditional analog instruments with digital screens
  • Provide more information in a compact, integrated format
  • Improve situational awareness and reduce pilot workload
• PFD (Primary Flight Display) combines flight instruments, navigation data, and aircraft status information
  • Typically located in front of each pilot
  • Enhances spatial orientation and decision-making
• MFD (Multi-Function Display) presents various systems, navigation, and weather information
  • Can be customized to show different pages or split-screen views
  • Helps pilots monitor and manage the aircraft's systems
• TCAS (Traffic Collision Avoidance System) detects and displays nearby aircraft
  • Provides visual and aural alerts for potential conflicts
  • Gives resolution advisories (climb or descend) to avoid collisions
• GPWS (Ground Proximity Warning System) alerts pilots when the aircraft is too close to the ground
  • Uses radar altimeter and terrain databases to detect hazards
  • Issues warnings for excessive descent rates, terrain, and obstacle clearance
• Autopilot systems maintain the aircraft's heading, altitude, and speed
  • Reduce pilot workload and improve precision, especially during long flights
  • Can be coupled with navigation systems for automated guidance
• FBW (Fly-By-Wire) controls replace mechanical linkages with electronic signals
  • Computers interpret pilot inputs and send commands to actuators
  • Provide envelope protection, stability augmentation, and smoother control response