Date: 201708
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Citation X (C750)
Operator: Fractional
Operating under: Part 135
Mission: Passenger
Flight phase: Parked
Aircraft component: Pressurization Outflow Valve
Component problem: Malfunctioning
Reporter organization: Fractional
Reporter function: Technician
Reporter qualification: Maintenance Airframe; Maintenance Powerplant
Human factors: Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Routine Inspection
Result: General Maintenance Action
Contributing factors: Aircraft; Incorrect / Not Installed / Unavailable Part; Procedure
Primary problem: Procedure

Narrative: The two discrepancies written up on Aircraft X.1) The aircraft would pressurize on the ground with engines off and APU running with APU bleed air selected on.2) Thrust reverser red disable panel missing from loose equipment bag.The pressure problem was a repeat problem. In the previous sign off the cabin pressure controller was changed without an inspector block signed on the form. While performing trouble shooting I found the aircraft would pressurize to approximately 25 LBS differential at a rate of 6000 FPM. The cabin dump switch had no effect. The only way to depressurize the aircraft was to turn the APU air off.  This created a dangerous situation when the cabin door was opened. I found a stuck check valve in the service air system. There was no service air to the left system which has the vacuum ejector to provide the vacuum for control of the outflow valves. The previous time the aircraft was 'repaired' there can't have been an operational check performed. It cannot have worked. The pressure controller would have passed the bit check but not an actual functional check.Upon arrival to the aircraft I received a parts shipment. It contained an unfinished thrust reverser disable panel; it was un-drilled and had no attach hardware. I photographed it along side of the correct part and requested the correct assembly be ordered. Maintenance control stated the correct part could not be ordered and to paint the panel red and install it on the aircraft. I contacted Cessna team x and got the correct part number and pinning kit part number as well. Cessna had 12 in stock. I provided maintenance control with proper numbers and was again asked to paint the incomplete panel red. I asked Maintenance Control to provide the correct parts or remove the MEL from my work package. It was removed. The correct part number was not in the 'system' therefore it could not be ordered. As it turns out this was a repeat problem also. Previously the aircraft was written up for a missing t/r lock out access panel 'white panel'.  The previous maintenance removed the red panel from the loose equipment; painted it white and installed it on the aircraft.A very high percentage of the aircraft I am assigned to repair have multiple repeat write ups. In every case the previous repair has a single signature on the form and no inspector signature. Where is the safety net? Why are the other maintenance providers not held to any safety standards? I am an employee of the ZZZ repair station; I am required to have an inspector on maintenance performed. I believe all maintenance performed should have a quality inspector present. The maintenance controllers should not pressure for a sign off. Having to stand my ground over piece of loose equipment is ridiculous.




Synopsis: CE-750 Maintenance Technician reported a pressurization problem was not repaired correctly and an incorrect part was supplied for a thrust reverser lock-out panel.