Date: 201709
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Reporter organization: Air Carrier
Reporter function: Dispatcher
Human factors: Confusion
Anomaly: Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
Contributing factors: MEL; Procedure
Primary problem: Ambiguous

Narrative: For two days I have had this MEL in the MEL book. It is very confusing as to what a dispatcher needs to do to safely plan out the fuel so while reading this MEL you can clearly see it has a flight level restriction but in a section called 'flight crew procedures' it's very hard to read between the lines. It does not say that an AC PAC is out so one would not think that you need to have the ECF required off on the MTOW to be selected. When reading it I personally thought this seems like a constant speed drive MEL due to the fact that it says the APU will be running all the time now. I was still not sure if my understanding was clear so I asked some other dispatchers that work [these aircraft] everyday what this MEL was all about and they all said based on reading this MEL that it would seem I need to do the performance worksheet for a constant APU. Maintenance control does not know what I am talking about when I ask does this require me to drop the ESC required off in the MTOW because they don't know what I am talking about when I ask that. In closer inspection the pilot on this flight knew this MEL and has had it before and called to tell me the ECS has to be off and showed me in procedures that it has to be selected off. To my knowledge the section was only for pilots and did not reflect what I would have to do on my own work. But even in the MEL where it talks about the ESC it says 'ECS on T/O DATA SET on MCDU; OFF' the pilot said that has to be the ECF required off in the performance numbers on the release. After the mistake was brought to my attention I asked [another dispatcher] what he thought again about this MEL and he said that Aero DATA needed to ECF required off to get the numbers for this MEL because it will always force it off Pilot brought it to my attention that I was in the wrong it needed to have the ECS has to be off for this MEL before the flight was even boarded The Cause was lack of knowledge of the MEL and the Lack of clarity of what dispatchers should do when the MEL is listed. I talked it out because we had time before the flight; I try to keep an open mind as to why a person thinks this way; just because the pilot says he has had this MEL before doesn't mean that its right. I talked it out and had come to the conclusion that the flight restriction it was acting as if the AC PAC was out. I understood it from that point of view and agreed to quickly get out a new release that would have the correct way on it. The MEL; NEF; and CDL procedures needs to have a section just for dispatch we need to know exactly what to do. We need to have the drop downs mention; I can only see this helping out pilots as well if we had the MEL. NEF; and CDL pages say ''you need to see this comment'' on the release or ''look for this as well to know penalty was calculated''. Some CDLs already have enroute; landing; and takeoff restrictions but even that to a new dispatcher might be confusing if they really don't read the MTOW. I would love to even see a google chrome shared page where as a dispatchers we can see what we need to do to make the MTOW correct and safe for flight.




Synopsis: A Dispatcher reported that it was very confusing trying to interpret the MEL book to safely plan out a flight with proper fuel loads and weight restrictions.