GRT Avionics, Inc.
May 2019
Sport SX Install. Manual
29
Rev. A
the best technique is to point the airplane in the direction to be tested, wait at least 20
seconds (or until the heading is not changing) and then taxi until the ground track is stable.
The difference between them is the magnetic heading error. If it is excessive, the fine
magnetometer calibration should be repeated.
5-14: How Accurate Should the Magnetic Heading Be?
Achieving a highly-accurate magnetic heading requires that the magnetometer be
installed in a good location on the airplane, and that the orientation of the AHRS and
magnetometer are accurate. The attitude data from the AHRS is used to process the
magnetic field data from the magnetometer, and due
to the steep angle of the earth’s
magnetic fields (only about 20° off vertical), every degree of attitude error will cause 3° of
heading error.
Heading errors of less than 5° are not normally apparent in normal flying, but errors this
large will cause the cross-wind component of the wind speed to be less accurate. For
every 1° of heading error, 1.7% of the forward speed of the airplane will be falsely reported
as a cross-wind. Thus, with only a 5° heading error, an airplane flying at 100 knots will
show a false crosswind of 8.5 knots.
5-15: Required Settings Before Flying!
In addition to the ability to interface with a large variety of third-party equipment, the Sport
SX allows the user to customize many aspects of the EFIS. Some of these settings are
to support pilot preferences, such as what data they wish to be displayed in the data
boxes on the PFD. Other settings are provided to support redundant inputs, labels used
to identify navigation inputs, etc…
Before flying, we recommend setting at least the following items:
•
All settings described in the previous subsections of
Section 5: INITIAL
CHECKOUT, BASIC CONFIGURATION SETTINGS AND CALIBRATION
.
•
All settings described in the
Equipment Supplements
that are applicable to the
peripheral devices that are connected to your EFIS. The supplements can be found
on the GRT website: (
www.grtavionics.com/home/compatible-equipment/
•
All settings in the following table:
Setting
Set Menu
Notes
Speed/Distance Units
General Setup
Fuel Units
General Setup
If Fuel Flow is installed.
Stall Speed Landing
Primary Flight Display
Stall Speed Clean
Primary Flight Display
Max Flap Speed
Primary Flight Display
Max Struct. Cruise Speed
Primary Flight Display
