Commercial Fixed Wing
Maintenance Airframe; Maintenance Powerplant
Confusion; Troubleshooting; Situational Awareness; Distraction
Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Company Policy; Environment - Non Weather Related; Human Factors; Procedure
I was assigned to accomplish a de-preservation of the APU on Aircraft X that has been in storage.  The documentation for the aircraft stated that the aircraft had been in storage for XXX days and the APU needs to be de-preserved before XXX+1 days. The APU will need more work accomplished if it is de-preserved after the XXX+1 day mark than if it is de-preserved before the XXX+1 day mark.  The issue is that the APU had a placard attached that stated the preservation was good until date and after the APU compartment was opened there was a different tag that stated the APU preservation was valid until date+4 days.  So there were two different dates documented for the APU for the XXX+1 day mark.   The question is when is this XXX+1 day mark?  The date that the APU was actually preserved or the date for the preservation / storage of the aircraft.
Technician reported confusing dates relating to work that needed to be performed on an aircraft that had been in storage.