Flight Controls
The flight control simulation covers the Airbus Fly By Wire computers and their 3 control laws, Normal, Direct and alternate. The Flight Controls model take input from the joy stick or Autopilot and through the relevant control law drive the surfaces, elevator, aileron, spoilers and rudder. The model also includes the Alpha protection and over speed protection control laws and computes the limit speeds for eth Primary Flight Display.
Equations Of Motion
At the heart of the aircraft simulation is the 6 DIOF quaternion equations of motion. These accept inputs of aerodynamic forces and moments, ground reaction forces and moments and engine forces and moments. In addition the model allows for step changes in wind and altitude and position. A WG85 type geographical model computes actual latitude and longitude for the rest of the simulation.
Engine
The engine model is a simple LFI type model of a 2 spool N1 type hi bypass fan engine. The actual engine parameters of a CF6 or RR Trent engine are used to scale the outputs of the simple model to produce representative thrust, EGT, and fuel flow parameters. A FADEC model interfaces the engine to eth throttle box model, and passes data to the displays.
Auto Brake
The Auto brake models allows the automatic activation of main gear wheel brakes for touch down and rejected take off. The auto brake values are determined from the A/B selection on the landing gear panel. The Auto brake models also sets the "Decel" light on the panel. When the speed brake lever is fitted the A/B model will be armed using the status of the speed brake handle.
ADIRU
The ADIRU model is split into the traditional Air Data System (ADS) model and the Inertial Reference system (IRS) model. The ADS has a complete model of 3 Air Data computers and 3 Pitot static models, which can include varying static error to allow for slightly different readings. The 3 Pitot static models fully account for any ground static pressure variance. The IRS models 3 IRU, which correctly model the sensed aircraft accelerations and velocities at their location in the airframe. The ADS and IRU correctly respond to inputs form the over head panel and from the MCDU.
Weight and Balance
The weight and balance model computes the aircraft mass, and cg as fuel is used and passes this information onto the FMGS. Its input is the inertia model located in the Equations of Motion.
Phase Of Flight (POF)
Through out the avionics models there is a need to compute the POF for use in system logic. This model produces one generic POF and two specific POFs, one for the Warning Computer and one for the FMGS.
