Emilio_G,
I'd suggest you to use the SetDataOnSimObject function to trigger a failure, like in the following example (it's Delphi but you'll easily grasp the idea):
first add it to data definition
SimConnect_AddToDataDefinition(hSimConnect, ord(DATDEF_SETENG1ONFIRE), 'ENG ON FIRE:1', '', SIMCONNECT_DATATYPE_INT32)
then call whenever you want it
SimConnect_SetDataOnSimObject(hSimConnect, ord(DATDEF_SETENG1ONFIRE), SIMCONNECT_OBJECT_ID_USER, 0, 0, 0, 0)