EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Communication Breakdown; Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Took Evasive Action; General Flight Cancelled / Delayed; General Maintenance Action; General Release Refused / Aircraft Not Accepted
Aircraft; Human Factors; MEL; Procedure
Aircraft X was scheduled for flight ZZZ to ZZZ1.  First Officer (FO) and I reviewed the aircraft maintenance issues prior to arriving at the airport noting MEL 27-11 and associated MELs.  At the aircraft during preflight; I reviewed the MEL procedures for 27-11 and worked with FO Name to perform the test procedures listed.  The test stated: To verify both control columns are connected; proceed as follows:  1. Hold LH control column in neutral position. 2. Try and move RH control column forward and backward. 3. If there is no relative movement between the control columns; they are connected.  While performing this test; we could see that if the LH column was moved the RH column didn't move at all; and same with the RH column.  We immediately called Maintenance Control who said that didn't sound right; and said he would call Maintenance back to the aircraft.  Note: the disconnect handle was still in place.  Once Maintenance arrived; we performed a flight control check with the hydraulics on.  At this point; it was noted the LH column only controlled the left elevator and the RH column only controlled the right elevator. No EICAS messages populated.  The only EICAS message was 'Pitch trim Disconnect' which was associated with the original MEL.  Maintenance was confused and said they had done all the control checks and that everything checked ok.  We sincerely believe that had a flight been attempted; it could have resulted in a catastrophe. Poor maintenance flight control checks.  Aircraft released to line with defective controls. I believe if maintenance had read the MEL and done the control check that was listed; they may have caught the system malfunction.
EMB-175 Captain reported MEL procedures determined that aircraft had flight control issues and could not be flown until maintenance corrected the problems.