B767-300 and 300 ER
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
General Flight Cancelled / Delayed; General Maintenance Action
Aircraft; MEL; Procedure
We flew Aircraft X from ZZZZ to ZZZZ1 to ZZZ. We operated with deferral 36-11-8-1-1a and 21-51-1-1. Under these conditions; the left AC pack should have been operated off. It wasn't! The flight should have not departed ZZZZ. The crew that was scheduled to fly Aircraft X from ZZZ to ZZZ1 noticed the discrepancy. The flight from ZZZ thru ZZZ1 to ZZZ was uneventful. I accept full responsibility for this event. I failed to take the proper time to review the MEL prior to the flights. After maintenance was performed on the aircraft; I reviewed the MEL items with mechanic in ZZZZ. My review of the MEL was obviously not thorough enough. I don't understand how I could have overlooked several of the items in the MEL; but I did. I should have been more proactive in including the First Officer in the decision making process. First Officer is an excellent pilot and this should not reflect poorly on him. I was very tired that day. This may have been a distraction. Considering everybody involved with this event; several people dropped the ball. Ultimately I am responsible.
Captain reported misreading multiple MEL's and departed an airport with a non airworthy aircraft.