Discrepancy: Elevator sluggish, sloppy, or heavy.
Possible Fix: Replace Elevator Feel and Centering Unit
Tip:
You can go back in the tail cone and look at the springs on the feel and centering unit. The AIPC reference is for the location of the springs. If they are broke you replace the whole Unit.
Following replacement make sure you bleed the Feel actuator both hydraulic systems. This system is very prone to problems caused by air in the system. Bleeding should be done while at all airspeed settings. Continue to bleed the system until no air is visible during bleeding.
Air in the system can cause problems with the Elevator feel force system and Autopilot Authority- System test. It could cause the values of spring force required for movement to be off at different airspeed settings.
Reason/Explanation:
Elevator feel is provided by a feel computer and a feel and centering unit. The feel computer provides varying hydraulic system A and hydraulic system B pressure inputs to the feel and centering unit. The feel and centering unit then applies a resistance at the aft control quadrants to simulate elevator aerodynamic forces.
Air in the system will cause intermittent Elevator Feel lights in the flight deck, along with spring forces required to the control column for a measured movement to be out of tolerance. It is smart to bleed both hydraulic systems at the Elevator Feel Actuator, following the units replacement.
Applicable Reference:
AMM 27-31-64-004-001, 27-31-64-404-002, 27-31-00-735-033, AIPC 22-22-00-11a item 155, 160
Thanks to Tom S. for his input !
