INTERFACES

In addition to their display allowing the engine control and monitoring by the crew, some engine parameters can be used for other engine or aircraft functions. Here are some examples:

1. ENGINE INTERFACES:

  • Signals of fuel temperature and oil temperature.

  • The N1 signal.

  • Vibration signals.

  • The N2 signal.

a) Signals of fuel temperature and oil temperature: they are sometimes used by the ECU or the EEC to control the fuel-oil heat exchanger.

b) The N1 signal: it can be used by the EEC or the ECU to replace the EPR signal when the electronic engine controller operates in a “alternate” or “stand-by” mode and when the EPR is the thrust parameter.

c) Vibration signals: they can be used by the engine balancing system (when it is installed) to calculate the corrective solutions for the vibrations of shaft N1.

d) The N2 signal: it is mainly used by the ECU or the EEC for the fuel proportioning, but is also used to close the start valve and to shut down the ignition circuit during the start sequence. Finally, the N2 signal can be used for the management of the turbine case cooling (control of TCC turbine plays) and to automatically re-start the engine in flight, when an abnormal engine deceleration is detected.

2. AIRCRAFT INTERFACES:

  • Fuel Flow (FF) signal: it is used to calculate the overall consumption (used fuel) which may be displayed permanently on the screen (CDU) of the flight management system. The data “overall consumption” (used fuel) is used to calculate the fuel remaining on board.

  • Oil low tension signal: it can be used on some aircrafts by various systems to determine if the engine is under operation or not.

  • The N2 signal. It is used often by many aircraft systems which must know if the engine is running normally (over idling speed) or not (below idling speed).

    Here are some examples of the aircraft systems which can use the N2 signal:

    • the air conditioning system for air flow management in air-conditioners.

    • the air conditioning system for the management of the cooling system of the electrical and electronic appliances.

    • the system of electrical power for the management of the shedding circuit.he fuel system for the DC fuel pump control.

    • the hydraulic system for the ram air turbine control (RAT: Ram Air Turbine).

    • the system of anti-icing for the management of external probe reheating.