Right, let's pick this up where we left off — Page 540, Lesson 646

Right, let's pick this up where we left off. We were talking about how the ECAM system on the A320 evolved to include engine data on one of its display units. Now, I want to shift focus to the other major electronic instrument system you'll see on modern aircraft: EICAS. First, a quick note on the smaller aircraft. On those with electronic flight decks where space is tight, you won't always see the full six-screen layout common on Airbus and Boeing. Instead, they might use a more compact arrangement. That could be an EFIS for the flight instruments, plus a separate Engine and Warning Display, or EWD. Alternatively, they might combine the electronic flight instruments and the engine indications onto a single unit called a Multi-function Display Unit, or MFDU. Now, let's get into EICAS itself. The name stands for Engine Indication and Crew Alerting System. The basic system is built from two display units, a control panel, and two computers. These computers receive both analog and digital signals from the engine and system sensors. Here's the key part about those two computers. They're designated 'Left' and 'Right'. Only one is in control at any given time; the other sits on 'standby'. If the active computer fails, you can switch control to the other one, either manually or automatically. That's your redundancy. Working alongside the main EICAS displays, you have discrete caution and warning lights, standby engine indicators, and a remotely-located panel used for selecting maintenance data displays. So the system gives the flight crew two main things. First, it shows primary engine parameters on a full-time basis. Second, it displays secondary engine parameters and any warning, caution, or advisory alert messages, but only as required. So to tie it together: EICAS is your centralised engine and alerting hub, with a dual-computer setup for reliability, and it prioritises what it shows you based on urgency.