Date: 201811
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: IMC
Light: Night
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Parked
Aircraft component: Data Transmission and Automatic Calling
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate
Result: General Maintenance Action
Contributing factors: Human Factors; Procedure; Aircraft
Primary problem: Human Factors

Narrative: Inbound aircraft arrived late; and we met inbound crew at aircraft. There were two open write ups on aircraft from crew; one was auto land the other was the Controller Pilot Data Link Communication (CPDLC). The CPDLC was written up as inoperative in air and ground. The mechanic took the logbook and stated that it would take him 'some time with the plane as he was unfamiliar with the CPDLC system.' We verified that the CPDLC system was inoperative. Approximately one hour later the mechanic stated that he was still working on the write ups. Now nearly two hours after departure; he was no closer to telling us what his plan was. He stated that he would run some tests. He and another mechanic conducted tests on the various data links; and noted the HF had an issue. Several times they came in and stated that the ZZZ mechanics were 'screaming at why I wrote this up.' I reminded him that we did not write this up...we received the aircraft with two open write ups. That said; the CPDLC system was clearly inoperative. I made numerous calls to the ZZZ flight operations personnel. I was repeatedly told the following: 'CPDLC is like a cellphone...you don't need this so why you concerned about it...this is a not a maintenance issue and should never have been written up and you are delaying the flight with a ridiculous issue.' All of these comments were both condescending and inappropriate. We were told countless times that perhaps we were unclear on how to use the system and simply were not initiating it correctly. This too was insulting and completely incorrect. At one point the flight ops individual asked for the First Officers (FO) phone number to call him and instruct him on how to use the system! I worked with the dispatcher and we both agreed that the MEL did not provide any clear guidance on deferring this system. It simply was not addressed. The mechanic stated that this was NOT a part covered or required by the MEL. I was told by the ZZZ maintenance personnel that 'this is not a maintenance issue; this is an issue between you and the dispatcher!' They said; again; it was like a cell phone and we did not need it. Flight ops then tried to point us to the [manual] and said we did not need the system and to just leave it alone. We pointed out to the maintenance folks that the only reference to this system could be found in the ACARS section. The MEL addresses the idea that the ACARS can be deferred; rendering the CPDLC system inoperative and clearly notes that many functions of the ACARS may be operative. I was rudely told that 'we do NOT defer operative systems'. This is untrue since part of the system was inoperative; i.e. the CPDLC; and this would have made for a legal deferral. The dispatcher and I were in complete agreement that this would be an acceptable remedy to the open write up. Instead; after we had been sitting in the plane for nearly five hours; the mechanic came back with the log book; this was the first time since our arrival to the plane that we had been privy to the logbook; and had written the following: 'performed CPDLC operational check per B767 AMM 1. Ops check well.' This type of sign off is used for corrective action that indicates an operational piece of equipment. This was NOT the case. The CPDLC system remained inoperative. I stated this and was told that he did his checks and they were good so he felt it was ok. I reminded him that it said REJECTED and was inoperative. His response was that it was not his problem. I called flight ops and the dispatcher. The dispatcher and I were NOT ok with this and wanted the ACARS deferral since this would represent a legal way to indicate that the system was not working and was being deferred in accordance with the MEL. Flight ops gave me the cell phone analogy yet again and kept asking us why we were even questioning this as they said it was not a required system. I advised them of the ACARS deferral option and they told me to write up what we saw; i.e. REJECTED indicating inoperative CPDLC and they would get with maintenance to get the ACARS deferred. They let us sit for another 30 mins and returned with a refusal to defer the ACARS. I was then called and given the cell phone analogy yet again and told that they do NOT defer operative systems. Again this is incorrect but he told me we needed to move the airplane. I stated that the mechanic had incorrectly stated in the logbook that the system was 'ops checks good' and that this was incorrect. He stated that he would provide us with a written statement directing us to depart and that all applicable maintenance procedures had been complied with; resulting in an Airworthiness Release (AWR) for the aircraft. This is what I received via ACARS:' Air Carrier X/ MAINTENANCE HAS ACCOMPLISHED APPLICABLE MAINTENANCE PROCEDURES AND HAS PROVIDED AN AWR. DUE TO INABILITY TO LOG ONTO CPDLC / [flight] IS AUTHORIZED TO PROCEED USING VOICE PROCEDURES IN ACCORDANCE WITH THE AOM.' The dispatcher required this statement as well in order to refile us and provide a [flight plan]. He and I felt that the write up had not been properly addressed. The mechanic then put the following as corrective action for the write up I documented indicating the REJECTED and inoperative CPDLC: 'CPDLC system checks good per 767 AMM'.Again this is indicative of corrective action remedying the issue and this was NOT the case. The system remained inoperative. Please reference the following from FAA Advisory Circular 120-70C: 'A revision to the OpSpecs includes specific authorizations; training and maintenance programs; manuals; operational procedures; minimum equipment lists (MEL); and other such areas necessary for safe and effective use of data link communications.' This advisory addresses the idea that CPDLC systems are not merely 'cell phones' but are aircraft communication systems whose functionality must addressed in the MEL. I completely agree that this item was not required for the flight and had no impact on the safety of the flight. The issue I had with this was what I believe to be the improper sign off by maintenance on an item that they stated was functional while it clearly was not. I do not believe that the logbook corrective action was correct and that the MEL effectively addresses this issue or system. We departed for ZZZ more than five hours late with a deferral for the auto land and a downgrade to cat 1. The CPDLC system was inoperative; but our logbook indicated it as 'ops check well.' More than four hours time was spent without any real input from us with the mechanic performing various checks and then leaving to go speak with ZZZ. We spent the last hour trying to obtain a deferral that we felt addressed the CPDLC inoperative status.




Synopsis: Air Carrier Captain reported an acceptable entry in the aircraft logbook regarding CPDLC being inoperative.