The Engine/Warning Display (E/WD)

The E/WD (the centre upper screen) is the main arena of the second detection phase, identification — the aircraft writes "what failed and what to do" in plain English in its lower half; the upper half permanently shows engine primary parameters, fuel on board and slat/flap position. This article covers how that screen is laid out, how primary and secondary failures are marked, why it "goes quiet" on takeoff and landing, and the T.O CONFIG test that must be pressed before every departure.

1. The E/WD upper part — four kinds of resident data (each to its source chapter)

Per FCOM DSC-31-15:

"The upper part of this DU displays: • Engine parameters • Feedback messages • Fuel on board (FOB) • Position of slats and flaps. The lower part of this DU displays messages generated by the FWC: • Warning and caution messages when a failure occurs, • Memos when there is no failure."

The four upper items each belong elsewhere: engine parameters → ATA-70, feedback messages (CHECK EWD etc.) → the reconfiguration article, FOB → ATA-28, slats/flaps → ATA-27. What ATA-31 truly owns is the lower part — where the FWS writes warnings and memos. So read the E/WD in two halves: the top for engine health, the bottom for what the aircraft is shouting.

2. The E/WD lower part — two zones, each with its role

The lower part is dedicated to ECAM messages, in a left and a right zone of seven lines each. Per FCOM DSC-31-15:

"Left part: - Primary or independent warnings and cautions, or - Memo information. Right part: - Title of system affected by a primary or independent warning, or caution, in the case of overflow on the left part, or - Secondary failure, or - Memo, or - Special lines (e.g "AP OFF", "LAND ASAP")."

Character data (AMM): left 7 lines × 24 characters, right 7 lines × 12 characters. The zoning: the left holds the "leads" (primary/independent failures + left memos), the right holds the "supporting cast" (secondary failures, overflow titles, special lines, right memos). Special lines have the highest priority — AP OFF, LAND ASAP always sit at the top of the right zone, above memos or warnings. So the scan is "left for the primary failure and actions, right for secondaries and the LAND ASAP class".

3. Primary and secondary failures — box the primary, star the secondary

The concept was set in the philosophy article; here are the marks. Per FCOM DSC-31-15:

"The ECAM DU displays a primary failure as a boxed title. It identifies a secondary failure by putting a star in front of the title of the affected system. Note: The DU displays the overflow symbol, if primary or secondary failures overflow. In case of ECAM SINGLE DISPLAY, the secondary failures are inhibited."

A box = primary failure (root), a star = secondary failure (cascade) — a glance separates "which is the cause, which is dragged in". One important degradation: in single-display mode (only one ECAM screen left) secondary failures are inhibited — with limited screen the primary is preserved and secondaries dropped. Action lines have a nuance. Per FCOM DSC-31-15:

"As soon as the FWC detects a failure... the E/WD displays the title of the failure and the actions that the flight crew must perform. The action line automatically clears when the flight crew performs the necessary action. Note: Some action lines do not disappear from the E/WD even after the flight crew performs the necessary action."

"Clears when done" is the norm, but some action lines remain even after completion — a reminder not to read "the action line is still there" as "I did not do it right": some lines (a state to be held) are designed not to clear. On overflow a green down-arrow appears at the bottom; press CLR to scroll.

4. Ten flight phases and takeoff/landing inhibition

The FWC organises its functions by ten flight phases and inhibits alerts in high-workload phases. Per FCOM DSC-31-15:

"The FWC divides its functions according to these ten flight phases... To improve its operational efficiency, the computer inhibits some warnings and cautions for certain flight phases... In these two phases, the DU displays magenta memos: "T.O. INHIBIT" (flight phases 3, 4, and 5), and "LDG INHIBIT" (flight phases 7 and 8). Note: These flight phases are different from, and independent of, the ones used by FMGEC."

Memorise the inhibition phases: T.O INHIBIT = phases 3/4/5, LDG INHIBIT = phases 7/8. The magenta T.O INHIBIT / LDG INHIBIT at the top-right of the E/WD tells you "inhibition is active, non-critical alerts are held down". The footnote "FWC phases ≠ FMGEC phases" is important — students confuse ECAM's flight phases with the FMS's; they are two independent divisions. A timing nuance: a failure appearing in phase 2 waits until phase 3 (which does not inhibit it) to display; a failure in phase 1 displays at once and persists into phase 2. The RCL button can temporarily lift the inhibition (see the ECP article).

5. Memos — the gentle reminder in normal operation

Without a failure the E/WD lower part shows memos — the positive face of the lights-out philosophy: not a wall of lights for "normal", but a few memo lines of "functions temporarily in use". Per AMM 31-51-00:

"MEMO messages are displayed in the lower zone of the E/WD. The typical MEMO messages are: - APU AVAIL - SEAT BELTS... The MEMO messages which comprise action lines can be managed by pairs: - ITEM (green)...ACTION (cyan) when the action is to be carried out - ITEM + ACTION (green) when the action is carried out."

The memo's green-cyan pairing is a to-do list: a cyan action line reminds "not done yet"; done, the whole line goes green — e.g. "T.O AUTO BRK ...... MAX" (green...cyan) becomes all-green "T.O AUTO BRK MAX" once armed. In the takeoff and landing phases the memo area also lifts up the key items of the normal checklist (T.O MEMO / LDG MEMO — LDG SIGNS ON / IGNITION / GEAR DN / SPLRS ARM), where ECAM manages the checklist for you (developed in the operation article). Memos are normally green, and amber in an abnormal state.

6. The takeoff-configuration warning — a one-press self-check before departure

The E/WD carries a key pre-departure test. Per FCOM DSC-31-15:

"The following warnings and cautions appear in the lower part of the E/WD if the aircraft is not in takeoff configuration when the flight crew presses the T.O CONFIG pb on the ECAM control panel or applies takeoff power."

The T.O CONFIG button is a test that simulates applying takeoff power — it checks the flight controls, slats/flaps, trims, spoilers, parking brake, doors, brake temperature and so on are in a safe takeoff configuration. The items are of three types (type 1 flight-control non-cancellable, type 2 parking brake, type 3 brakes-hot/doors — mechanism in the ECP article). In the correct configuration the T.O MEMO shows a green steady T.O CONFIG NORMAL. The key discipline: even if you do not press T.O CONFIG, applying takeoff power (or the phase 2→3 transition) triggers any untested configuration warning — so the test exposes a wrong configuration early, before you find it on the runway.

Self-test

[!note]- Q1. What are the four upper E/WD items and their chapters, and which half does ATA-31 truly own? Engine parameters (ATA-70), feedback messages (ATA-31 reconfiguration), FOB (ATA-28), slats/flaps (ATA-27). ATA-31 owns the lower part — the FWS warnings/memos.

[!note]- Q2. What does the left zone hold, what the right, and which class always sits at the top of the right? Left: primary/independent failures + left memos. Right: special lines, overflow titles, secondary failures, right memos. LAND ASAP / AP OFF (special lines) always at the top.

[!note]- Q3. How are primary and secondary failures marked, and what happens to secondaries in single-display mode? Primary boxed, secondary starred. In single-display mode secondary failures are inhibited.

[!note]- Q4. Which phases are T.O INHIBIT and LDG INHIBIT, and what must you note about FWC vs FMGEC phases? T.O INHIBIT = 3/4/5, LDG INHIBIT = 7/8. FWC flight phases are different from and independent of the FMGEC's.

[!note]- Q5. What does the T.O CONFIG button simulate, and what if you do not press it before applying takeoff power? It simulates applying takeoff power to test the takeoff configuration. If not pressed, applying takeoff power (or the phase 2→3 transition) triggers any untested configuration warning anyway.

Key takeaways

References

• FCOM DSC-31-15 — E/WD upper/lower, left/right zones, primary/secondary marks, overflow, ten flight phases and inhibition, memos, takeoff-configuration warning.
• AMM 31-51-00 — lower-zone character counts, inhibition timing, memo green-cyan pairs, T.O/LDG memo.

Independent study material, not an Airbus publication and not endorsed by the manufacturer. Always defer to the current operator FCOM, FCTM, and QRH for operational use.