Ng :- Deu/eec ?

[kotakota]

Can anyone explain the connection between the DEU and EEC ? ie why do EECs go into ALT mode when DEU fails ?

[PLJ]

Data from aircraft "sensors and systems" are channelled through the DEUs. EECs take an output from the DEUs so that they can accurately assess how much thrust is needed.

If a single DEU fails there is only one DEU left (ie. single point of failure) so the EECs revert to a more basic function (alt hard/soft).