B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 180
Time Pressure; Confusion; Situational Awareness; Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance
General Maintenance Action
Aircraft; Human Factors; Procedure
The aircraft arrived early with a flight director problem. Maintenance MELed the write-up. In the process they discovered the AFCS EXC AC circuit breaker popped and would not reset. This led to the addition of six more inter-related MELs that had to be addressed; to include collaring several circuit breakers. After verifying the appropriate application of each of the seven MELs; we pushed about an hour late. The plan was to have the repairs done in ZZZ after passing through ZZZ1. The flights from ZZZ to ZZZ1 and ZZZ2 were uneventful. In ZZZ1; Maintenance attempted to repair the aircraft; they were unable to repair it and returned it back to its originally MELed status. In the process they collared an additional circuit breaker that was not collared in the first instance. Additionally; one of the circuit breakers previously noted as collared does not actually exist (B AFCS sensor exc DC circuit breaker). The Captain had a lengthy discussion with Maintenance Control (including a picture of the actual write-up in Denver sent via cell phone).  It was determined the 'D' in DC was actually an 'A'; making it AC. We continued on and terminated the aircraft.
I believe this aircraft should have been pulled [out of service] and not allowed to leave in its condition. Additionally; I believe that my First Officer and I were set up to fail by having to apply seven MELs in a compound situation; not only from a safety aspect; but from a potential FAA action standpoint; in the event any portion of this complicated procedure was found to have not been executed properly after the fact. To my knowledge; I believe we acted appropriately and legally; but I should not be placed in a situation where I have to guess or wonder.  I'm also embarrassed that the originating crew tomorrow will [receive] this aircraft in its current condition.
A malfunctioning Flight Director; for which maintenance had no immediate resolution; ultimately resulted in multiple MEL deferrals that were intended to be resolved at a subsequent stop. After two uneventful legs maintenance was unable to resolve the problem at the planned repair station. Instead; they found another item they believed was required to be deferred. A subsequent in depth investigation; including emailed pictures of the original write-up; uncovered the source of the confusion; it was the incorrect interpretation of the letter 'A' instead of 'D'; thus changing 'AC' to 'DC'.