Controls and ECAM Reading

Everything the crew can do to the fuel system lives on one overhead panel; everything the system says comes back through the EWD, the SD FUEL page, and the refuel panel's lights. This article is the reading course: each control with its lights and its FAULT triggers, the SD page symbol grammar, the EWD memos that flag an abnormal fuel configuration — and the two or three displays whose meaning is genuinely non-obvious (the half-boxed FOB, the only number on the page that can turn red).

1. The overhead FUEL panel

FAULT-light logic rewards close reading. The centre-pump FAULT is the best example — it lights for four conditions, not one: low delivery pressure; the centre tank empty with the pump still commanded; a disagreement in the transfer logic; and the trim-pipe isolation valve failed open — that last one because a stuck-open trim line gives centre-pump pressure an uncommanded path aft (trim-tank fuel unusable, scenario A). A FAULT light is a symptom set, and the ECAM alert that accompanies it tells you which member fired.

2. The SD FUEL page — symbol grammar

            ┌───────────── FUEL page reading order ─────────────┐
            │  F.USED engine totals (top, with engine LP valves) │
            │  pump symbols per collector cell + standby         │
            │  X FEED valve symbol (centre)                      │
            │  tank quantities: OUTER · INNER · CENTRE · TRIM    │
            │  transfer valve symbols on their lines             │
            │  tank temperatures (LH outer, inners, trim)        │
            │  FOB box (bottom) · CG figure                      │
            └────────────────────────────────────────────────────┘

Valves (one grammar fits all — LP, crossfeed, transfer, inlet):

Pumps: in-line green = delivering; crossline white/green = off/not delivering as selected; amber = LO PR where it should deliver.

Quantities carry the FCMC colour code from FCMS computers: green digits; amber dashes on the last two digits = degraded; flashing = imbalance (also the post-refuel >3 000 kg signature); XX = no data.

Two displays deserve their own paragraph:

[!warning]- The half-boxed FOB When part of the fuel on board is unusable — trim fuel declared trapped, centre fuel written off behind dead transfer pumps — the FOB figure is shown with an amber half-frame: the number still counts every kilogram aboard, the half-box warns that not all of it can reach an engine. Fuel-remaining decisions in those procedures must start from FOB minus the trapped amount, and the half-box is the display's way of saying so.

[!warning]- CG is the only figure on the page that turns red Tank quantities degrade to amber; the CG value turns red when the aircraft exceeds the aft limit (the FMGEC's judgement — the same watchdog that stops CG control). A red CG outranks every other number on the page; the EXCESS AFT CG alert family is its EWD voice.

3. EWD — the memo lines

The memo column is the "abnormal configuration set on purpose" channel. The fuel members:

The two refuel memos are the pre-departure contract: every refuel-panel switch back, door closed, memos gone — the AMM's trigger lists make each switch position individually capable of holding the memo up (refuelling).

Above the memos, the permanent FOB on the EWD and the per-engine F.USED figures are the raw material of the conservation check (FOB + ΣF.USED vs departure FOB, every waypoint or 30 minutes — fuel management); the FWC runs the same arithmetic continuously and raises FUEL F.USED/FOB DISAGREE past 3 500 kg (quantity and level faults).

4. The refuel panel's own lights

On the 990VU: per-tank blue HI LVL lights (wet sensor = tank full), amber OVERFLOW lights (surge-tank sensors — same hardware that drives the in-flight WING TK OVERFLOW alert), END (steady = refuel complete; flashing = a stop condition or accuracy miss — the full list in refuelling), and CKPT (control held by the cockpit pushbutton). The HI LEVEL TEST exercises the lot: lights toggle, quantity windows show all 8s, and the inlet valves drive closed while the protection proves itself.

Self-test

[!note]- Q1. Name the four conditions behind a centre-pump FAULT light. Low delivery pressure; centre tank empty with pump commanded; transfer-logic disagreement; trim-pipe isolation valve failed open (uncommanded aft path for the pump's pressure).

[!note]- Q2. Crossline amber on a valve symbol — what does it tell you, and what doesn't it? Position disagrees with command (or in transit) — it does not tell you which side is lying; the accompanying ECAM alert and the system behaviour decide that.

[!note]- Q3. What does the amber half-frame around FOB change about your fuel arithmetic? Usable fuel = FOB minus the trapped quantity. The figure counts everything aboard; the half-box flags that part of it cannot reach an engine.

[!note]- Q4. Which figure on the FUEL page can turn red, and on whose authority? The CG — red beyond the aft limit, per the FMGEC's independent monitoring.

[!note]- Q5. The REFUEL PNL memo is up with the panel door closed. What are the candidate switches? MODE SELECT not OFF, any tank valve switch out of NORM, TRANSF VALVE at OPEN, or panel power selected to BAT.

Key takeaways

References

• FCOM DSC-28-20 (controls and indications, pilot level); DSC-28-10-130 (FUEL page).
• AMM 28-25-00 §7.E (EWD refuel-message trigger lists); AMM 28-42-00 (990VU indications, colour logic).
• The reading-order framing and "symptom set" characterisation are integrative synthesis.

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.