how much do the avionic systems account for of aircraft cost
30%
what is the main driver for avnionic systems
minimisation of flight crew and automation
2 crew operations result in savings in what
- salaries
- weight
- training
- expenses
secondary drivers of avionic systems are
- impoved safety
- reduction in maintenance costs
- allows for operations in all weathers
- better control/handling & performance
What systems interface directly with the pilot
- Displays
- communication
- data entry and control
- flight control systems
what is a display systems
provides visual interface between pilot and aircraft systems
what 3 types of displays are there
- heads down display (HDDs)
- heads up display (HUDs)
- helmet mounted display (HMDs) aka HUDs on helmets
why is communication systems important
- allows for communication between aircrafts and base
- essential for air traffic control
what does a data entry and control system do
allows the pilot to interact with the on board avionics systems via keyboards, panels and direct voice input (DVI)
in flight control systems, what 2 categories are they
- auto-stabilisation
- fly-by-wire control system
what are auto-stabilisation systems most commonly used for/in
- swept wing aircraft and combat aircraft
- ost have 3 azis auto stabilisation
what does a fly-by-wire control system do
allows for care-free manoeuvering by restricting some of the pilots commands according to aircraft state;
proves continuous auto-stabilisation via manipulation of flight control surfaces by the computer
In the aircraft state sensor system, what are the 3 sub systems
- air data systems
- inertial sensor systems
- navigation systems
what air data quantities are needed to navigate the system
- altitude
- calibrated air speed
- true airspeed
- vertical airspeed
- mach number
- air stream incidence angle
what measurements are taken to calculate the air data quantites
- static pressure
- total pressure
- air temperature
- air stream incidence sensor
aircraft alititude and heading are important to
- pilot fluing in poor weather conditions or executing a manoeuver
- subsystems such as auto-pilot, navigation and weapons aiming
what tools allow heading and alititude to be calculated
on board gyros and accelerometers
what are the 3 types of systems
- dead reckoning (DR)
- Radio
- external world sensors
feautres of a DR system
- finds position by estimating distance traveled from known position
- self containing and independent of external systems
- requires position updating
feautres of a radio nav system
based on ground/satelltie transmitters
- computer derives positions from transmitter signals
- ground beacons along air routes provide range and bearing info
- instrument and microwave landing systems give approach guidance in poor visibility
feautures of external world sensor systems
-weather radars mounted on civil airlines detect water droplets; wanrs of storms; cloud turbulence and severe precipitation ahead of aircraft
what are the 3 subsystems of an engine control and management system
- full authority digital engine control system (FADEC)
- engine health monitoring system
- house keeping management
feautes of the FADEC
- engine responds to throttle commands in in optimum manner
- ensuresengine limits ie. temp are not passed
features of a health monitoring system
-measures, processes and records a range of parameters to give early warnings of: engine performance deterioration; high vibration levels; excessive wear; fatigue damage
