EFD1000 Installation Manual
DOCUMENT # A-01-126-00 PAGE 154-225 Revision H
© Copyright 2009 Aspen Avionics Inc.
MAGNETOMETER CALIBRATION
CAL HDG: 030.0º
Figure 10.32 – Calibrated Heading after adjustment
Now repeat the process above for all other headings in 30º increments from 60º to 360º.
Press the MENU key to exit the Installation Menu. Continue with heading accuracy tests in
Section 10.5.4.
NOTE: In some aircraft, prop wash and wind during ground operations can create
inconsistent pressures in the pitot-static system. The pressures can affect the ADAHRS,
resulting in small pitch and heading perturbations. Before reading the aircraft headings
for the purposes of calibration, ensure the attitude solution has stabilized and is not
influenced by external winds and pressures. The disturbances normally settle out over a
period of 15 to 60 seconds. Idle power or temporarily selecting the alternate static
source can sometimes eliminate the effect.
10.5.4 Heading Accuracy Test
As a final check, position the aircraft on the headings shown on “Installation Final Check
Sheet” of Appendix B and verify heading (viewed on HSI display) is within +/- 4 degrees
using a calibrated heading source (i.e., sight compass, compass rose). Record actual PFD
headings in the table for inclusion in aircraft maintenance records.
If any heading is outside ±4º then rerun the Calibration Procedure and or Heading Offset
adjustment.
10.5.5 Heading Interference Test
With aircraft engine(s) running monitor current aircraft heading on PFD and exercise flight
controls stop to stop including flaps and any electric trim tabs. Verify the heading (viewed
on HSI display) does not change on the PFD by more than 2º. If movement of flight
controls causes more than a 2º heading change then it may be necessary to degauss the
flight controls including the cables. A handheld degausser can be found at most audio
and video stores.
Operate all electrical and environmental equipment including:
• Blowers, fans, heaters, air conditioner
• Deice boots, fuel pump(s), backup vacuum pumps
• Landing, logo, NAV lighting
• Operate pulse equipment – transponder, WX radar, DME
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