Aircraft FADEC System

A380V/SB747-AIRCRAFT/ FADEC - ENGINE A380V/SB747-AIRCRAFT/ FADEC - ENGINE

GENERAL

The Full Authority Digital Engine Control (FADEC) system manages the engine thrust and optimizes the performance.

 FADEC

The FADEC consists of the Electronic Engine Control (EEC) and its peripheral components and sensors used for control and monitoring. The EEC is in relation with the other A/C systems through the Engine Interface Unit (EIU). The primary parameters Engine Pressure Ratio (EPR), Low Pressure Rotor Speed (N1), High Pressure Rotor Speed (N2), Exhaust Gas Temperature (EGT), and Fuel Flow (FF) are sent directly by the EEC to the ECAM.

Secondary parameters:

- the oil quantity and oil pressure are sent to the DMCs by the SDACs. In case of SDACs failure, the EIU sends data to DMCs by the FWCs, - the oil temperature is sent by the EIU to DMCs via thhe FWCs, - the fuel used data is directly sent to DMCs via the EEC, - the vibration parameters are sent by the EIVMU to DMCs via the SDACs.

EIU

Each EIU, located in the avionics bay, is an interface concentrator between the airframe and the corresponding FADEC located on the engine. There is one EIU for each engine.

POWER MANAGEMENT

The FADEC provides automatic engine thrust control and thrust parameter limit computation. The thrust is computed according to the Engine Pressure Ratio (EPR) in normal mode or N1 in back-up mode. In fact, when the Engine Pressure Ratio (EPR) mode is no longer operational theFADEC automatically reverts to the N1 alternate control mode. The FADEC manages power according to two thrust modes: - manual mode depending on the Throttle Resolver Angle (TRA), - auto thrust mode depending on the auto thrust function generated by the Auto Flight System (AFS). The FADEC also provides two idle mode selections: - approach idle, - minimum idle.

Approach idle is obtained when the slats are extended. Minimum idle can be modulated up to approach idle depending on air conditioning, engine anti-ice and wing anti-ice demands.

ENGINE LIMITS

The FADEC provides overspeed protection for N1 and N2, in order to prevent the engine from exceeding limits, and also monitors the EGT and Engine Pressure Ratio (EPR).

ENGINE SYSTEMS

The FADEC provides optimal engine operation by controlling the: - FF,

- compressor airflow and turbine clearance. 

IGNITION AND STARTING

The FADEC controls the engine start sequence. It monitors N1, N2, and EGT parameters and can abort or recycle an engine start. The FADEC controls the ignition and starting in automatic or manual mode when initiated from the ENGine start or ENGine MANual START panels.

THRUST REVERSER 

The FADEC supervises the thrust reverser operation entirely.

Credit :    Rabindar Singh

Sharing is Caring & Helping Eachother

You May Also Like These