STANDBY HYDRAULIC LOW QUANTITY • Hydraulics

NNC STANDBY

ConditionCondition

Quantité Standby < 50 % — voyant LOW QUANTITYStandby system quantity < 50% — LOW QUANTITY light

ObjectifObjective

Confirmer une vraie perte STBY vs indication spurious — croiser avec quantité B.Confirm a real STBY loss vs a spurious indication — crosscheck with system B quantity.

Le voyant LOW QUANTITY Standby est toujours armé (contrairement à LOW PRESSURE, armé seulement pompe activée).The Standby LOW QUANTITY amber light is always armed (unlike LOW PRESSURE, armed only when the pump is activated).

Seuils catalogCatalog thresholds

USG	EIS	SignificationMeaning
2.80	100%	Plein STBYSTBY full
1.40	50%	Seuil LOW QUANTITY — perte STBYLOW QUANTITY threshold — loss of STBY

Armement voyantLight armingToujoursAlways Seuil qtyQty threshold< 50% PleinFull2.80 USG LOW QTYLOW QTY1.40 USG

Croisement système BSystem B crosscheck

Fuite STBY → B tombe vers ~64 % EIS. Si B reste nettement plus haut → spurious probable.STBY leak → B falls toward ~64% EIS. If B stays much higher → likely spurious.

Vérifier que la quantité système B indique environ 64 % (EIS), ou entre ½ et la ligne RFL (non-EIS). C’est le niveau catalog pour une fuite STBY (table B : 4.95 USG / 64 %).Verify System B quantity indicates approximately 64% (EIS), or between ½ and the RFL line (non-EIS). That is the catalog level for a STBY leak (B table: 4.95 USG / 64%).

Si B montre une quantité nettement plus haute que ces valeurs → indication STBY Low Qty probablement spurious.If system B shows a considerably larger quantity than those values → Standby Low Qty indication is probably spurious.

Ce que STBY alimenteWhat STBY powers

STBY Rudder (STBY RUD SOV)STBY Rudder (STBY RUD SOV)
LE Flaps / Slats (chemin ALTN)LE Flaps / Slats (ALTN path)
Eng 1 / 2 Thrust Reversers via STBY (si A ou B perdu)Eng 1 / 2 Thrust Reversers via STBY (when A or B lost)

Réservoir STBY alimenté depuis qty B — d’où le croisement obligatoire.STBY reservoir is fed from B quantity — hence the mandatory crosscheck.

Liens composésCompound links

STANDBY LOW PRESSURE — armement différent (pompe activée)STANDBY LOW PRESSURE — different arming (pump activated)
LOSS OF SYSTEM A / LOSS OF SYSTEM B — faire STBY LP NNC avant Descent Deferred si STBY aussi perduLOSS OF SYSTEM A / LOSS OF SYSTEM B — do STBY LP NNC before Descent Deferred if STBY also lost
MANUAL REVERSION — A+B+STBY → rudder perdu · PI NO REVMANUAL REVERSION — A+B+STBY → rudder lost · PI NO REV

Table complète : Hydraulic System. QRH / FCOM papier fait foi.Full table: Hydraulic System. Paper QRH / FCOM prevails.