Disagree between the Roll and/or Pitch and/or Lateral Acceleration Indications on the PFDs and on the ISIS Indicator

TASK 34-22-00-810-815-A
Disagree between the Roll and/or Pitch and/or Lateral Acceleration Indications on the PFDs and on the ISIS Indicator

1. Possible Causes

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 34-22-25-000-001	Removal of the ISIS Indicator
AMM 34-22-25-400-001	Installation of the ISIS Indicator
Tolerances limit of the ISIS Indicator (22FN) installation

3. Fault Confirmation
Subtask 34-22-00-700-061-A ** ON A/C NOT FOR ALL

A. Test
(1) Not applicable, the fault is evident.

4. Fault Isolation
Subtask 34-22-00-810-070-A ** ON A/C NOT FOR ALL

A. Test
(1) Make sure that the indications of the ISIS indicator are in the tolerances that follow:

Tolerances limit of the ISIS Indicator (22FN) installation ** ON A/C NOT FOR ALL

Roll: less than 2.5 deg. (equivalent to 1/4 of a roll graduation) (item A),
Pitch: less than 1.25 deg. (equivalent to 1/2 of a pitch graduation) (item B),
Lateral Acceleration: less than 1.3mm (item C).

NOTE: After a long low-rate turn with a bank angle of less than 10 degrees (holding pattern, for example), it is possible that the ISIS bank angle indication will not be accurate immediately. A period of as much as three minutes after the turn can be necessary to get an accurate indication again.
If such a condition is reported in the logbook, but on the ground the ISIS indication is in the tolerances, it is not necessary to remove the ISIS indicator.

(2) If the roll and/or pitch and/or lateral acceleration indications on the ISIS indicator is(are) out of tolerance:
(a) Remove the ISIS indicator AMM 34-22-25-000-001.
(b) Make sure that the housing of the ISIS indicator is clean (without washers, bolts, etc.).
(c) Install the ISIS indicator AMM 34-22-25-400-001.
(3) If the fault continues, replace the ISIS indicator AMM 34-22-25-000-001 and AMM 34-22-25-400-001.

[Rev.8 from Aug 2018] 2026.04.04 04:32:57 UTC