How do you read the Airbus A320 BLEED page in a sim?
In the real Airbus A320 and a flight simulator, the ECAM BLEED page is the pneumatic-system schematic. It shows whether engine, APU or ground air is available, the actual position of routing valves, bleed pressure and temperature, crossbleed configuration, and whether each air-conditioning pack is receiving air.
What does the A320 BLEED page show?
The display connects every usable pneumatic source to its consumers in one schematic; it monitors the system but does not control it. In Microsoft Flight Simulator, X-Plane and Prepar3D A320s, commands come from the overhead pneumatic controls while the lower ECAM System Display reports the result. Our guide to locating the ECAM pages and overhead controls explains how those panels fit together.
- Engine bleed sources: The left and right sides represent engines 1 and 2, including bleed-valve status and regulated pressure and temperature.
- High-pressure source valves: Engine bleed normally uses an intermediate compressor stage. The HP valve can open automatically when that stage cannot provide enough pressure, then close again as engine conditions change.
- APU and ground air: These provide alternative pneumatic sources on the ground, although simplified aircraft may omit some ground-air indications.
- Crossbleed valve: This joins or isolates the left and right pneumatic manifolds.
- Pack flow-control valves: These show whether bleed air is being admitted to
PACK 1andPACK 2.
A valve is usually drawn as a circle containing a line. A line parallel to its duct means open; a line across the duct means closed. Green normally indicates a valid, normal state, while amber can identify an abnormal value, fault or disagreement between commanded and actual position. A green closed valve is not automatically a fault.
How do you read the Airbus A320 BLEED page?
Read the page from the active air source towards the packs, checking that every required valve creates an uninterrupted route.
- Find the source. With both engines running, expect an engine source on each side. With engines off and the APU supplying air, look for an open APU bleed valve. External air must be connected before its path can become available.
- Check pressure and temperature. Valid green figures confirm that the source is producing usable regulated air. Do not memorise one exact value: engine power, altitude, pack demand, anti-ice use and aircraft modelling all affect the indications.
- Trace the valve positions. Follow the duct from the source, through the engine bleed or APU valve and towards the manifold. A closed valve breaks that route even when pressure exists upstream.
- Inspect the crossbleed valve. In
AUTO, it normally opens when APU bleed is selected and closes when the APU bleed valve closes.AUTOdoes not automatically connect the manifolds for every single-engine situation. - Check both pack valves. A pack selected on can still have its flow-control valve closed automatically during engine start, at low upstream pressure or following certain failures.
- Read the ECAM message as well. The schematic shows what the system is doing; the upper ECAM warning identifies the fault and any required action. Randomly cycling valves can hide the original configuration without fixing it.
What should a normal A320 BLEED page look like?
The normal picture changes with the aircraft’s operating state, so compare the display with the configuration rather than expecting every valve to remain open.
| Configuration | Expected source and routing | Pack indication |
|---|---|---|
| Both engines running | Each engine normally supplies its own side; crossbleed closed | Both pack valves normally open when selected on |
| APU supplying on the ground | APU bleed valve open; crossbleed normally opens in AUTO | Both packs can receive APU air |
| Engine start | APU or external air supplies the starter; detailed models may show the start-air path | Pack valves may close automatically, then reopen after start |
| One pneumatic source available | Its side is pressurised; the opposite side requires an appropriate crossbleed configuration | One or both packs may be supplied, depending on routing and demand |
Those changes make more sense when followed within the normal A320 before-start and engine-start sequence, rather than assessed as an isolated screenshot.
Why is a BLEED line or pack valve closed?
Most apparent BLEED-page failures in a simulator are caused by configuration or automatic start logic, not a failed pneumatic component.
- APU running but no bleed pressure: An available APU does not supply pneumatic air until
APU BLEEDis selected. Also check thatX BLEEDhas not been left atSHUT. - Pack closes during engine start: This is usually normal load reduction. Leave the pack pushbutton in its normal selected state and allow the automatic logic to reopen the valve after start.
- No engine bleed indication: Confirm that the engine is running, its
ENG BLEEDpushbutton is on and no fire control has isolated the source. - Only one side is pressurised: With the APU off,
X BLEED AUTOdoes not act as automatic balancing between engines. Open it only when the applicable simulated procedure requires crossfeeding. - Amber valve or
XXdata: This can mean a valve disagreement, out-of-range sensor value or invalid data. Follow the ECAM message before attempting a reset.
A mistake we see constantly is assuming that every closed valve should be opened manually. HP valves, pack valves and the crossbleed valve all change position automatically as pressure demand and aircraft configuration change.
Why does the BLEED page differ between A320 add-ons?
Every A320 simulation uses the same basic pneumatic logic, but the modelling depth and graphics vary substantially. A simplified aircraft may animate only the major valves, while a high-fidelity add-on can model pressure changes, HP-stage selection, start-air demand, sensor faults and valve transit delays.
For a practical example, our Fenix A320 cold-and-dark start walkthrough shows how electrical power, APU bleed, pack valves and engine start interact. If another simulated A320 does not reproduce every intermediate indication, that may be a limitation of its systems model rather than an incorrect cockpit setup.
Does the BLEED page show cabin pressure?
No. The BLEED page covers pneumatic generation and distribution as far as the air-conditioning packs. Cabin altitude, differential pressure and outflow-valve position belong on the PRESS page, while cabin-zone and duct temperatures are handled on the COND page.