Customer Service 800-496-9430 | www.zaon.aero
TROUBLESHOOTING54
Displays constant traffic DETECTION; unit constantly displays > 0.9 NM.
Any traffic displayed can only be from another transponder-equipped aircraft. The only source for traffic detec-
tion is from other valid aircraft (unless the unit is detecting your own transponder, see above). In order for traffic
to be displayed, XRX must decode a valid Mode C (altitude) signal code. Interference from your aircraft or avionics
cannot create this code, and the pilot should trust this indication. It is not uncommon to see a consistent display
of traffic within the detection window, especially when it is set to 6.0 NM as this is a large portion of airspace.
Common responses to constant traffic detection:
“I called ATC they said no traffic exists.” This is an unreliable way of checking for traffic. ATC doesn’t typically
indicate traffic which is not a factor. This means there may still be traffic around you which XRX will detect. In
addition, ATC may not necessarily be looking at a screen which shows all non-factor traffic. For example, some
controllers use a “1200 filter” which blocks all VFR traffic squawking 1200 from being shown.
“I don’t see any traffic and it says X.X NM” Traffic is typically not visible beyond 1.5 to 2.0 NM. Just because traffic
can’t be seen does NOT mean there is no traffic. First-time users may be surprised just how much traffic is nearby
that was previously undetected. Again, XRX cannot display traffic unless a valid Mode C transponder code is
detected.
“There can’t possibly be someone at 5.0 NM for 10 minutes.” Actually, this is very common. 5.0 NM may also
indicates traffic is GREATER than 5.0 NM. Does the unit show multiple aircraft? If so, several aircraft are within the
5-7 mile range. The only way for XRX to display traffic is to receive a valid code from another transponder.
These responses are typical for many pilots because they simply cannot SEE the traffic they assume it is not real.
Pilots must learn to trust the instrument, similar to trusting flight instruments during instrument flying.
The local altitude displayed is different from my altimeter.
XRX displays pressure altitude, not indicated altitude. It is using the same format as your transponder. Indicated
altitude will only match when your barometric pressure is 29.92”. To test this, set your altimeter to 29.92. It should
agree with your XRX within ±100 ft.
While flying, the local altitude displayed is significantly different from the current pressure altitude.
Check to ensure the pressure altitude was incorrectly computed. Check if the pressure has not changed since the
calculation. If problem persists, the unit may need to be recalibrated. See page 48, “Altimeter Calibration”.
Sometimes range information skips, for example, from 5.0 NM to 3.0 NM.
The transponder system on the target aircraft is not always transmitting; therefore this indicates the aircraft
moved through 4.0 NM without transmitting for XRX to range it. Also, as an aircraft changes positions, antenna
transmission lobes change, leading to signal alterations. This is normal.
When viewing an aircraft on takeoff, the unit did not detect the aircraft until it was airborne or at a certain
altitude.
The aircraft was probably below RADAR coverage. Typically, once an aircraft has obtained an altitude of 300-500
feet AGL, it will be in coverage and start transmitting. Also, many pilots initially forget to switch their transpon-
ders to altitude. XRX, as with any other collision avoidance system, will not be able to detect an aircraft unless the
target transponder is in altitude mode.
To Next Page
Loading...