All right, let's pick this up right where we left off — Page 552, Lesson 658

All right, let's pick this up right where we left off. We're in the middle of a real-world scenario on the ECAM system. We have a brake unit on the rear right wheel of the left main landing gear bogie that's overheating while we taxi out for take-off. Now, watch what happens. The system immediately displays a diagram of the wheel brake system on the right-hand display unit. At the same time, the left-hand unit displays the corrective action the flight crew needs to take. On top of that, an aural warning sounds, and a light placarded 'L/G WHEEL' illuminates on the central warning light display panel. Here's the key part about how the ECAM guides you through this. As you carry out the corrective action, the instructions on the left-hand display are replaced by a message in white, confirming the result of your action. And the diagram on the right-hand display unit is appropriately 'redrawn' to reflect the new state. Now, there's an important convention to understand here. In this example, the 'failure related mode' warning relates to a single system. By convention, such warnings are signified by underlining the system title displayed. But here's the contrast: in cases where a failure can affect other sub-systems, the title of the sub-system is shown 'boxed', as you can see in Figure 39.12. So remember: underlined title means the failure is contained to that single system; boxed title means the failure can propagate to affect other sub-systems. Now, how do you clear these warnings? Warnings and the associated lights are cleared by means of 'CLEAR' push-button switches, located on either the ECAM control panel or the warning light display panel. Let's move on to the Fourth Mode of the ECAM: the Manual mode, also called the Aircraft System Display Mode. This mode permits the selection of diagrams related to any one of 12 of the aircraft's systems for routine checking. It also permits the selection of status messages, provided no warnings have been triggered for display. The selections are made by means of illuminated push-button switches on the system control panel. Now let's look at the ECAM Control Panel itself. The layout is shown in Figure 39.13. All switches, with the exception of those for display control, are of the push-button, illuminated caption type. There are two types of switches I want you to know. First, the SGU Selector Switches. SGU stands for Symbol Generator Unit. These switches control the respective symbol generator units. The lights are off in normal operation of the system. The 'FAULT' caption illuminates amber if a failure is detected by an SGU's internal self-test circuit. Releasing a switch isolates the corresponding SGU, and causes the 'FAULT' caption to extinguish, and the 'OFF' caption to illuminate white. Second, the Synoptic Display Switches. These permit individual selection of synoptic diagrams corresponding to each of the 12 systems, and illuminate white when pressed. A display is automatically cancelled whenever a warning or advisory occurs. So to recap: the SGU switches manage the symbol generators that produce the displays, and the synoptic switches select which system diagram you want to see. And remember, any warning or advisory will automatically cancel your manually selected display.