td, thank you, and for the additional information and clarification, particularly the rates and differences between engines.
Are you able to answer aspects of the question at # 28.
My interest is in the extent of information available to the crew and levels of alerting. Particularly the availability of external assistance – real time reporting / monitoring, which might change/aid crew perspective or complexity in decision making, not only for the 777 but any aircraft with such capabilities. (Concepts of ‘Flt Eng on the ground’, or technological decision aiding.)
e.g. simple cases avoiding additional information – vibration etc
Old systems had engine oil low pressure Red Warning (cross check gauge) = shutdown
Latterly this is supplemented by an Amber Alert, where if the gauge is not in red zone = monitor / idle
In both cases oil-filter clogged (pressure drop across filter) was only available to maintenance, but what might the situation be if crews have access to the filter information, or more.
Modern aircraft appear to have much more information available, to whom, and in what circumstances. Who (or what system) makes the decision of what to display to pilots and who recommends what the action should be. (cf Alaska MD 80 where external advice may not have helped).