System Maintenance Manual

G1000/GFC700 System Maintenance Manual – C90A/C90GT/C90GTi King Air Page 4-35
190-00682-01 Revision F
a. AHRS2 pitch attitude does not change
b. An amber “PIT MISCOMP” is annunciated on PFD1 and PFD2
c. Autopilot disconnects at approximately 5 deg AHRS1 / AHRS2 miscompare
d. The autopilot disconnect audio alert (two hi-low tones) sounds
e. A red flashing AP annunciator on PFD1 and PFD2
f. Flight director command bars remain in view with PIT and ROL modes annunciated
14. Replace AHRS1 to normal attitude and verify that attitude display on PFD1 displays current
aircraft attitude.
15. Use the AFCS mode controller to re-engage autopilot.
16. Slowly rotate AHRS1 along the longitudinal (roll) axis to a roll attitude of greater than 5
degrees, verify the following:
a. AHRS2 roll attitude does not change
b. An amber “ROL MISCOMP” is annunciated on PFD1 and PFD2
c. Autopilot disconnects at approximately 5 deg AHRS1 / AHRS2 miscompare
d. The autopilot disconnect audio alert (two hi-low tones) sounds
e. A red flashing AP annunciator on PFD1 and PFD2
f. Flight director command bars remain in view with autopilot in PIT and ROL mode
17. Replace AHRS1 to normal attitude and verify that attitude display on PFD1 displays current
aircraft attitude.
18. Repeat Steps 13 through 17 for AHRS2.
19. The G1000 Miscompare checks are complete.