Date: 201812
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Night
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Weight And Balance
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors; Procedure
Primary problem: Procedure

Narrative: I was operating [flight] from ZZZ on a day requiring an alternate for our destination. In the [CRJ] 200; this has always been a closely monitored issue when it relates to loading of the aircraft with fuel. We had 50 passengers booked and a pilot listed for the jumpseat. The flight was already planned to land at our maximum landing weight with the new fuel program using 'Contingy' as required fuel. I contacted Dispatch when I noticed that my maximum takeoff weight was also my minimum takeoff weight using only taxi fuel to go from ramp fuel to legal takeoff fuel. I initially discussed getting an alternate airport that was closer requiring less fuel above the line to allow me to have more wiggle room for takeoff without the need to bump any passengers. Then; I received the cargo load report from the ground crew and saw that we only had 53 total bags between standard checked and gate claim bags which was less than planned. I was unable to take the jumpseating pilot because the amount of ballast needed would have exceeded my maximum flight plan takeoff weight. With the amount of fuel and payload I had on board; I only had to burn about 50 pounds of fuel after pushing back from the gate to be legal for takeoff. This was easy to do even with the short taxi we had; and we had no problems taking off below maximum flight plan takeoff weight and being above our minimum takeoff fuel.In cruise; I wanted to dig deeper into this release and the new fuel program since it was the first time I had been put into this tight corner as warned by the Flight Operations Bulletin sent out by the company. I was trying to reduce the amount of payload (PYLD) planned by the Dispatcher to reflect the actual payload; but I was told they did not have control over manipulating that. After looking at the three different revisions we had of the release for this flight; I noticed that all three had a different number. In the Flight Operations Manual; it states that this number is calculated by taking the number of passengers booked and multiplying by the seasonal weight; and then taking an average of one and one half bags per passenger and multiplying that by 30 to get the 'PYLD.' For this flight; I should have had a payload of 11;700 pounds with 50 passengers booked (50x189 plus 75x30); but instead I had 11;452 pounds. The closest I could come to that payload is if I change the seasonal weight of the passengers in the 200 to the summer weight of 184 which gives me a payload of 11;450 pounds using the same equation. Having said this; this is for revision three of this flight. Revisions one and two had a payload of 11;072 and 11;458 pounds with 50 passengers booked. I used this same formula to check the payload on old releases I had on my iPad at random; and I was able to come up with the PYLD exactly using the passengers booked. I am not sure what happened on this particular flight; but I was not able to come up with 11;452 pounds.I checked into the ACARS takeoff data and did the math on the actual loading of this flight by hand. Using the BOW [Basic Operating Weight] of 33;231; 50 passengers (all adults); and 53 bags all weighing 30 pounds each; I came up with a [number] that matched the numbers sent from ACARS. This told me that the numbers I did use were in fact the winter weights of the passengers; and I was not exceeding any limitations of the aircraft.  I then notified Dispatch via ACARS of what I had found; and he confirmed the math for PYLD; but he was unsure that the release was incorrect.I am not entirely sure that the PYLD on the dispatch release is always as simple as the equation in the Flight Operations Manual. There is much more to that software than necessary for me to know; but looking back at this flight I think there was an oversight on this number. The date on the release is the correct date and would therefore be winter weights; but I simply cannot come to a solution for how to get this number. If Dispatch was able to manipulate the bags to reflect a lower estimated bag count; this was not communicated or misunderstood by me on the two phone calls that I had before pushing back. I did not exceed a maximum takeoff weight nor did I take off with insufficient fuel; but with all the chaos that was going on for this delayed flight and trying to get a jumpseater in the flight deck to an airport with low ceilings; I may have overlooked an error on the administrative side of this flight.




Synopsis: CRJ200 Captain reported communications breakdown with Dispatch resulting weight and balance errors.