Learn what NAV/TCAS STBY means in the FlyByWire A32NX, which pedestal settings clear it, and when to use STBY, TA or TA/RA in MSFS.
NAV/TCAS STBY in the FlyByWire A32NX means the Traffic Collision Avoidance System is in standby, so it will not issue traffic or resolution advisories. It is not an autopilot NAV-mode message. In Microsoft Flight Simulator, set the transponder appropriately and turn the TCAS selector to TA/RA before flight.
What does the NAV/TCAS STBY message indicate?
The wording is Airbus-style alert syntax: NAV identifies the navigation and surveillance system group, while TCAS STBY is the condition requiring attention. At the gate or during shutdown, standby is normal. In flight, it means collision-avoidance protection has not been armed.
The transponder and TCAS are related but controlled separately. The transponder reports your identity and altitude; TCAS uses surveillance data to assess nearby aircraft. A valid squawk code does not arm TCAS, and selecting TA/RA does not help if the transponder itself remains in standby.
How do I switch on TCAS in the A32NX?
Use the ATC/TCAS panel on the centre pedestal to configure both the transponder and collision-avoidance mode.
- Complete the normal electrical set-up. A cold-and-dark aircraft can legitimately show TCAS in standby while its panels and displays are being powered.
- Enter the assigned squawk code. Use the code provided by simulator or online ATC. Press IDENT only when a controller asks for it.
- Set the transponder mode. AUTO is the normal Airbus selection because it manages the appropriate ground or airborne reporting state. Use ON only when a procedure or controller requires it.
- Turn the TCAS mode selector to TA/RA. This is the normal airborne setting and should remove the TCAS STBY indication once the system is available.
- Choose the traffic display filter. ALL displays the normal traffic picture, ABV favours traffic above, BLW favours traffic below, and THRT reduces clutter to relevant threats. This selector changes the display filter; it does not arm or disarm TCAS protection.
- Check the Navigation Display. An empty display does not necessarily mean TCAS is off—there may be no compatible simulator, multiplayer or injected traffic nearby.
Our explanation of the A320 ND, EFIS controls and traffic presentation covers the display context if the symbols or relative-altitude labels are unfamiliar.
When should I use STBY, TA or TA/RA?
Use TA/RA for normal airborne operation; STBY and TA are intended for particular phases or procedures.
| TCAS setting | What it does | Typical use |
|---|---|---|
| STBY | Disables traffic and resolution advisories | Parked aircraft, initial power-up or shutdown |
| TA | Provides traffic advisories but no resolution advisories | Procedure-specific ground use or when full RA capability is not wanted |
| TA/RA | Provides both traffic and resolution advisories | Normal take-off, climb, cruise, descent and approach operation |
Ground procedures vary between operators and online networks. A practical simulator flow is to leave TCAS in STBY while parked, select the required taxi mode after start, use TA/RA before take-off, and return it to STBY during shutdown. Transponder requirements on the ground are separate and may require AUTO even while TCAS remains in standby.
Why does NAV/TCAS STBY stay on?
A persistent TCAS STBY message usually means the wrong pedestal control was moved or a simulator binding is overriding the selector.
- Check the TCAS knob, not the traffic filter. Moving ALL, ABV, BLW or THRT does not change the standby state.
- Check the transponder selector separately. TCAS should be in TA/RA and the transponder should normally be in AUTO for full operation.
- Look for duplicate control bindings. A joystick, throttle quadrant or generic MSFS transponder assignment can force the cockpit switch back to standby.
- Finish the aircraft set-up. A dark or invalid Navigation Display is an electrical or display problem rather than evidence that the TCAS selector failed.
- Do not diagnose TCAS from an empty ND. Traffic must be present in Microsoft Flight Simulator and provide usable position and altitude information before the A32NX can show it.
Panel behaviour can differ as FlyByWire systems are revised. If the controls do not match a tutorial, check how Stable and Development builds differ before treating the mismatch as a fault.
What happens when TCAS detects another aircraft?
TCAS first classifies nearby traffic and then issues a TA or RA if the calculated conflict becomes serious enough.
- Traffic advisory (TA): an amber circle and a “TRAFFIC” alert draw attention to a potential conflict. Do not manoeuvre solely because of a TA; monitor the intruder and prepare for further guidance.
- Resolution advisory (RA): a red square and vertical guidance indicate the climb or descent response required. Follow the vertical guidance, remain outside prohibited red bands and return towards the cleared flight path after “CLEAR OF CONFLICT”.
The number beside a traffic symbol is relative altitude in hundreds of feet: +12 means approximately 1,200 feet above, while -07 means approximately 700 feet below. An arrow shows that the aircraft is climbing or descending rapidly relative to you. Ground and low-altitude inhibit logic can suppress certain advisories close to the runway.
Does TCAS control Microsoft Flight Simulator ATC?
TCAS and simulator ATC are separate systems: TCAS detects cooperative traffic, while ATC issues clearances, squawk codes and routing instructions.
Selecting TA/RA does not contact a controller, acknowledge an instruction or make the simulator fly an avoidance manoeuvre. Our guide to how MSFS ATC and transponder instructions work together explains that distinction. Multiplayer or injected aircraft may also be missing from TCAS when the simulator does not supply usable traffic or altitude data.