Regional Jet 200 ER/LR (CRJ200)
Maintenance Airframe; Maintenance Powerplant
Situational Awareness; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Aircraft; Chart Or Publication; Human Factors; MEL; Procedure
The [flight] crew called from ZZZ and said that the #2 Hydraulic System was reading 100 percent in the 'OFF' position; but reads correct pressure when in the 'ON' position. I then deferred the #2 Hydraulic Accumulator as in the past. The aircraft flew one leg and when Maintenance went to fix it; they found there was no # 2 Accumulator installed.The Accumulator had been removed based on an Airworthiness Directive (AD). The flight crew and I were unaware that they had been removed. And the MEL did not state it. We took the aircraft off-line and fixed the problem. That same day a note was put into the MEL stating the two accumulators had been removed from the aircraft.
A Line Mechanic reports he deferred the #2 Hydraulic System Accumulator on a company CRJ-CL65 aircraft under their MEL procedures after the flight crew reported incorrect pressure readings. Downline Maintenance reported #2 Hydraulic Accumulator had been previously removed per an Airworthiness Directive (AD); but their MEL had not been updated.