I’m developing a web-based application that generates loadsheets, which users can input into their flight computers. One of the app’s most critical functions is calculating Mean Aerodynamic Chord (MAC), and an essential part of these calculations is determining the passenger (PAX) weight.
In my research across different airframes and profiles, I’ve found that the PAX weight varies significantly, typically ranging from 75 kg to 86 kg. What’s most concerning is that nearly every airframe or SimBrief profile creator seems to use different PAX weights, which results in inconsistent Zero Fuel Weights (ZFW) across platforms. This makes it difficult for my app to calculate a ZFW that aligns closely with what SimBrief generates, which is crucial for producing realistic MAC/ZFW figures.
This inconsistency raises an important question: Why do different airframes use different PAX weights (e.g., 80 kg), even when the same passengers might be flying on multiple aircraft (e.g., transferring from an A320 to a 777-300ER)?
While I can adjust airframe details within my own SimBrief account to align with my app’s standardized weights, it’s impossible to guarantee that the thousands of other SimBrief users will do the same. This results in inconsistent outputs across the board.
Therefore, I’d like to suggest that SimBrief standardizes passenger weights for all users. A fixed value, say XX kg/XX lbs, could be applied to all airframes, ensuring consistency in PAX weight calculations across the platform. This would help developers like myself and SimBrief users achieve more accurate and reliable loadsheets.
Well the one of the reasons of having adjustable per-airframe passenger weights would be to match whatever the load and balance manager for the addon uses (e.g. 100 kg per passenger for ToLiSS, 80+15 kg for Fenix passengers, 210 lbs for the FF Boeings 757/767, whatever weight PMDG uses per passenger etc.).
If you remove that then the OFP is no longer in sync with the addon. Surely that can’t improve accuracy?
Perhaps we should lobby all addon developers to standardize their passenger weights so that all passengers weigh the same across the entire sim world.
I’m really glad you replied! I noticed that you’ve created a few airframe profiles on SimBrief—great work!
You’re absolutely right! Aircraft developers need to standardize passenger weights by taking an average across EASA and FAA regulations, accounting for seasonal variations (summer/winter) and male/female distributions. By averaging these six components, we can establish a consistent standard for passenger weights.
After that, SimBrief should implement this standardized number across all airframes and make it unchangeable.
Because this is the way it’s done in the real world. Across different countries, different airlines, and even different seasons (winter versus summer) or different routes within the same airline, average passenger weights can be different. There is no universally “correct” average passenger weight, so asking different add-on developers to conform to a specific value is not justified. It’s arguably less realistic to do this actually.
For your application specifically, if you are (or are planning to incorporate) importing a user’s latest SimBrief flight plan using the provided endpoint (documented here), you will note that the average passenger and baggage weight used for that specific flight plan is provided in the <weights> section. So you should not need to hard-code or keep track of what weights a given add-on uses to keep things in sync with SimBrief, just read the values from the OFP data when importing.
Thank you for this idea! I was indeed planning to implement a SimBrief import into my app. The development for the SimBrief import is now the next stage after we finish refining the calculations and adding a few more aircraft to our database. It’s a great suggestion from you to mention that passenger weight doesn’t need to be hardcoded and can also be imported.