Intermittent ﬂashing of dus may be indicative of a generator issue. If cm1 dus are ﬂashing, try turning oﬀ generator 1. If cm2 dus are ﬂashing, try turning oﬀ generator 2. The apu generator can be used if successful.
In the case of a blank du, a large amber “F”, a distorted display or minimum brightness, on some airframes a reset may be attempted by selecting the du brightness oﬀ then back on. If the reset is not applicable or the du does not recover after 10 seconds, the aﬀected du can be turned oﬀ. In the case of an invalid display unit message, an automatic recovery attempt is initiated; this can take 40 seconds or more. If automatic recovery does not succeed, the du can be turned oﬀ.
An invalid data message is indicative of a dmc problem; eis dmc switching may recover the du, as may turning the du oﬀ then on. It is possible that this message will appear simultaneously on all dus; this initiates an automatic recovery attempt, which, again, can take 40 seconds or more. dus that are not automatically recovered may be recovered manually by sequentially turning them oﬀ for 40 seconds then back on. If resetting a du triggers a recurrence of the original problem, leave that du oﬀ for the next recovery cycle.
In the event of an unrecoverable failure of a display unit, some automatic display switching will occur: pfd will auto-transfer to ndus and ewd will auto-transfer to sdu. Each pilot has a pfd/nd xfr button that allows their pfd to be toggled onto their ndu and their nd to be toggled onto their pfdu. An ecam/nd xfr switch on the switching panel allows either the sd (when sdu xor ewdu failed) or ewd (sdu and ewdu failed) to be displayed on an ndu.
The most likely end result of a du failure is that one nd must be shared and/or that the sd is not displayed. The ecam can be operated with just the ewd. When a sys page is needed, press and hold the required sys page button. When status is required, press and maintain the sts key. The ewd will be displayed 2s after the sts key is released. To access status overﬂow, release then repress the sts key within 2s.
[ qrh aep.eis, fcom pro.aep.eis ]
A faulty dmc can cause multiple spurious ecam alerts (spurious as conﬁrmed by sd pages). The eis dmc switch should be used to identify the faulty dmc and replace it with dmc3.
[ qrh aep.fws, fcom pro.aep.fws ]
The two identical fwcs generate alert messages, memos, aural alerts, and synthetic voice messages. Loss of a single fwc leads to downgrade to Cat 3 Single due to loss of redundancy. The major eﬀects of loss of both fwcs are loss of ecam (including attention getters, status page and takeoﬀ/landing memos), loss of auto callouts1 (radio height and decision height) and loss of altitude alerting. In the sim, there is also loss of rudder trim reset, loss of apu fuel valve status and loss of cabin crew call alert as side-eﬀects.
The procedure is simply to use the sys pages and overhead panel warning lights to monitor the systems, and for pm to make the relevant callouts. Alternative method for cabin crew to get ﬂight deck attention may be required.
[ fws fwc 1(2)(1+2) fault, fcom pro.aep.fws ]
1There is some question as to whether windshear and gpws aural alerts are included under ‘auto callouts’. The fcom is unclear on the matter.