Regional Jet 200 ER/LR (CRJ200)
Maintenance Airframe; Maintenance Powerplant
Training / Qualification; Situational Awareness; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
Flight Crew Diverted
Human Factors; Incorrect / Not Installed / Unavailable Part; Procedure; Aircraft; Chart Or Publication
I had on-call Maintenance in ZZZ1 deactivate the [Overboard] OB Shut-off Valves (SOVs) and (Inboard) INBD SOVs to comply with an [MEL] 'M' action [procedure] for MEL 21-24-05 and MEL 21-24-06-XX. I printed off the AMM references and faxed these to the on-call Maintenance [Provider]. Later my Trainer asked me if I had sent the [our] Air Carrier's Supplemental to the on-call Maintenance? I told him I had not and I assumed the on-call Maintenance provider had all the documentation he needed. On-call Maintenance performed the 'M' action and incorrectly deactivated the SOVs. With the [Overboard] OB SOV open the CRJ-200 aircraft was not able to pressurize and had to divert. [Recommend to] always reference the internal documents. Documentation missing.
Reporter stated he was a Maintenance Controller in training; working on an MEL for an Avionics cooling EICAS message. He was referencing a Company Supplemental Manual in his report when he mentioned Supplement (Supp). The Supplemental has enhanced information; diagrams and pictures to help Maintenance perform certain procedures. That Manual was sent to the On-call Contract Maintenance. Without the Air Carrier's Maintenance Supplement; the on-call Contract Maintenance provider had misunderstood the Aircraft Maintenance Manual (AMM) procedure and deactivated the Inboard (I/B) Avionics' cooling valve in the 'Closed' position and locked 'Open' the Overboard Shut-off Valve (SOV); when actually just the reverse procedure should have been accomplished. With the 4' inch wide Overboard Avionics cooling exhaust SOV locked in the 'Open' position; the CRJ-200 could not pressurize.
A Maintenance Controller in training reports that a company CRJ-200 aircraft was not able to pressurize after a Contract Maintenance provider had de-activated the Avionics cooling Inboard Shut-Off Valve to the 'Closed' position and the Overboard Exhaust SOV to the 'Open' position. Procedure was opposite from what the MEL required. Aircraft diverted.