Background
Dynon Avionics SV-ADAHRS-200/201 use airspeed in the calculation of attitude (or GPS ground
speed when airspeed is unavailable). The internal rate sensors are monitored and calibrated in
flight using feedback from the accelerometers and from airspeed to achieve a highly accurate
attitude solution.
When a pitot or static test is performed the sensors in the SV-ADAHRS-200/201 are being exposed
to dynamics that are impossible to achieve in a real aircraft flight environment, namely, large
airspeed changes without the accompanying accelerations and rotations. This false condition will
cause a well-calibrated unit to incorrectly adjust its calibration. Furthermore, when a unit is in a
test situation a change in applied pitot or static pressure will cause the attitude to pitch up or
down. This is expected.
The AF-5000 EFIS contains a special mode that allows you to perform required altimeter and/or
airspeed checks without affecting the calibration of the attitude-sensing components.
Pitot/Static Test Instructions
This test must be used when performing pitot/static, transponder, or other tests that manipulate
either the pitot or static pressures.
Before conducting any pitot/static testing, follow these guidelines:
1. The aircraft itself should be temperature stable. For example, if the aircraft is moved from
outside in the sun to a hangar for testing, tests should not be started until the airplane has
stabilized at the hangar temperature.
2. Turn AF-5000 on and let it warm up until the altitude reading is stabilized. This period should
be at least 5 minutes, but may take longer depending on environmental conditions. Connect your Pitot/Static Test Set to the aircrafts Pitot and Static ports. You will need to cover
the two Dynon Pitot Tube drain holes on the bottom of the Pitot Tube.
3. To enter the Altitude Test mode select: SET > CAL > 12. Altitude Menu on the EFIS. Both the
active and standby ADAHRS (if equipped) are shown to allow a single test to calibrated multiple
ADAHRS. The altitude values shown in this mode are the same as you would encounter while
in-flight with a Baro setting of 29.92 . They are not adjusted or otherwise altered from their
normal readings and behaviors.
4. Set Airspeed to stable constant airspeed on your Pitot/Static Test Unit, we usually use 65
knots.
5. Set Altitude Climb rate to a value of +/- 2000 fpm on your Pitot/Static Test Unit.
6. Perform a standard leak check on the Pitot/Static system before testing the required altitudes.
7. Set each required Altitude on your Pitot/Static Test unit and verify the altitude is within
acceptable limits on each ADAHRS.
ALTITUDE ADJUST:
There is a single point altitude adjustment for each ADAHRS that can be used to
adjust the barometric altimeter from the AHRS if it is not in tolerance. This adjustment affects both the
displayed altitude and the altitude sent to other devices.
Verifying Altitude
You can check the altitude from the Altitude Calibration Menu: SET > CAL > 12. Altitude Menu
The Configure Altitude Menu will display the non baro adjusted (29.92) altitude from each Adahrs in
the aircraft.
Manual ALT / GND mode switching
Transponder checks require manual switching to ALT
and GND mode. A Dynon Avionics SV-XPNDR-261/262
is normally configured to automatically switch
between GND and ALT mode based on airspeed and
other parameters. You can change the ALT/GND
Switch to NONE so that you can turn on the
Transponder ALT mode while on the ground.
Note: Before changing AUTO ALT/GND, record which squat switch configuration is set; you will need
this information to restore AUTO ALT/GND to this setting after transponder testing is complete.
Pitot/Static Test Chart