Hi,
A Fadec Engine control system basically
consist of an Electronic Engines Controller
or EEC, and assosiated sensors. There is
really no ´Black Magic´ involved, as some of
my fellow engineers would have you belive,
the EEC recives all the same parameters as a
traditional Hydromechanical fuel control does
, it just recives them as electrical signals.
It then computes, just as the mechanical one,
the required amount of fuel and then operates
a small electical fuel metering valve. The
main reason for having a Fadec system, is
that because nearly all parameters are
signalled electrically, you can monitor
many more, thereby optimising your engine
control and fuel burn. As an illustration the
good old JT8D had 5 controlling inputs, all
mechanical or pneumatic, the V2500 has 22,
most of them electrical a few pneumatic and
only one mechanical (N2). A couple of added
benifits are that the EEC can ´Synthezise`
that is, calculate a parameter if the
affected sensor is inop. And finally it is
much easier to troubleshoot because the EEC
monitors all it´s own sensors.
[This message has been edited by DoctorA300 (edited 20 January 2001).]