Converting baggage and cargo between SimBrief and IF

I was messing around with Simbreif and came across something that proved a little confusing to me. I initially thought the solution was simple, but realized it was much more complicated than I thought initially.

So, from Simbreif’s user guide, it says that it calculates the total number of passengers as 230 lbs, 175 per person and 55 for their bags. However, from what I know, infinite flight only calculates for the person and not the bags.

This is what I had been doing previously: input the correct IF zero fuel weights, MTOW, and MLW weights onto SimBreif to get the most accurate fuel readout. But, autofill will give you 0.0 cargo on SimBreif, and I knew that SimBreif already calculated baggage weight with passenger count. However, now that I realize that IF doesn’t calculate it that way, how should I go about this?

So, the questions:

Question 1: Since IF does not calculate “passengers” including their bags, in order to get the most accurate read out, will I actually have to go back and multiply 55lbs x (number of PAX) in order to get the accurate weight from SimBreif.

Question 2: Since SimBreif calculates 175 per person, is this actually an accurate representation of what IF calculates per passenger? If not, what is the weight per passenger on IF?

Question 3: SimBreif’s cargo on auto actually remains set to “0.0.” Is this realistic for real world travel? What is a realistic input value for additional cargo besides passenger bags? Again, note that passenger bags do not count as cargo in SimBreif, but apparently do count as cargo in IF.

Sidenote : Yes, I do realize that all of this is not necessary, and that each passenger will not actually weigh 175, and each bag 55. What matters is the fuel, and yes I understand I can estimate.
For realism’s sake, to get to the closest real world simulations, I was wondering about these conversions, because apparently, its a lot more complicated than just plug and chug values.

1 Like

I’m sure long hauls and flights to international hubs have more cargo onboard. I was actually curious about this myself after I generated a flightplan with SimBrief today. I don’t think it accounts for flight type, so it just keeps cargo at 0 unless you change it manually.

What I usually do is set passenger and fuel weights in IF accoring to SimBrief. Then the difference between SimBrief TOW and IF TOW goes to cargo. Might not be the most realistic way but it matches the numbers in both systems and then I’m sure I have enough fuel for the flight and I’m not taking more than I need.

1 Like

SimBreif does actually provide a way to change the TOW, ZFW, and empty weight, which I already have installed a fleet for. I have gone in and edited the aircraft so that they are actually the same exact specifications for Infinite Flight.

But the difference resides within cargo and baggage, which I think alters from Infinite Flight and SimBreif in regards to how they calculate both, which is what I was wondering about.

I realized that there wasn’t a way to do it without cold numbers and conversions which I didn’t have, so I decided to come to the community with my issue.

You can change this, you can set your desired fuel and cargo weight but, you’ll need to change your zero fuel weight (ZFW) from automatic to the weight adjusted on IF then your fuel weights would be accurate for your flight.

1 Like

The problem with that is, that is converting weights from IF to SimBreif. What I want to do is use the weights from SimBreif and convert those weights to IF.

That is indeed the easy way to handle things, but for simulation purposes, my questions are about the other way around.

I see what you are saying. It looks like adding baggage to cargo in IF is the way to go, at least for now.

In regards to your second question, have you tried comparing the weights for an equal number of passengers? Say, put 100 pax and no cargo in SimBrief, generate the flightplan, and subtract the baggage weight (55x100) from the payload weight indicated in SimBrief.
Then load 100 pax in IF and see how that weight compares to SimBrief weight.

I’m actually curious about this now lol

1 Like

I know, I was doing a flight to Mexico City with a much lighter “cargo” payload and realized that I landed extremely light. I went to the SimBreif user guide to compare values, and realized that the passenger values on SimBreif are actually nothing like that compared to what IF uses in terms of passengers and their baggage.

Seems like a lot of conversions for some bags, but hey, if you strive for realism, you can’t always take the easy way out.

1 Like

I was under the assumption simbreif didn’t calculate for baggage. What I do for the 787 is

(PAX)*20+2000(food water and stuff)/20000 * 50.9
I get 15.27 and I input that

I then do the same with cargo planes or smaller planes, Pax * twenty, + food / total cargo load * the simbrief max number

Food and water weight is under a completely different category. I don’t think SimBreif calculates that. You’d have to input that in under “cargo” as a separate item from the other payload.

Also, 15.27 in what unit? Lbs? Thousands of pounds? Minutes of fuel?

Where are you getting the numbers 20 and 20,000 from?

15.27 in simbrief cargo units

20 is the amount of cargo, 20kg for each person. The 787 has a total load of 20,000kg

1 Like

Actually, adding water and other stuff is too redundant and will result in weight miscalculation. Food, water, and all other supplies like crew weights are part of Empty Operating Weight (a.k.a. Basic Operating Weight), which is accounted for in IF.

@labibmamun, it looks like IF weighs each passenger at around 170 lbs, which is around 20-25 lbs below the industry standard depending on the season, but pretty close to SimBrief.

1 Like

It seems like the 170 is pretty close to what it is on simbreif. In the end I will be off by 100-200 lbs at the most. But that means I’d still have to do baggage separately as cargo.

So after calculating for passengers you’d have to go back, and multiply (# of PAX) times 55+5 (which is the average bag weight, plus the 5 lbs difference from IF). And then again, that still doesn’t include extra payload, or flight attendants, or food/water, etc…

In order to do that, you’d have to calculate it differently, because flight attendant and pilot bags usually weight lighter than PAX bags, and then again, they are heavier when doing long hauls and short haul flights.

It is a whole complicated process.

Is basic operating weight including flight attendants, and other supplies in IF. I actually did not know that.

Guess that is another flaw I’ve been messing up.

Yes, that’s correct, so you don’t even need to worry about how heavy the crew bags are, that all should be determined by the manufacturer.
I think calculating passenger baggage as cargo is not a bad idea, given that both end up in the same compartment anyway :) Also, weight distribution in IF is pretty basic, so all you need to be sure about is that TOW and fuel for the flight in IF are equal to those in SimBrief.

Here’s a small chart that I found, it should help a bit.

1 Like

I have just one fundamental question:

Does it matter to what the weight is ascribed as long as you use the same weight? (i.e. if you have 20000 lbs of non-fuel, non-empty weight, does it matter whether half is passengers and half cargo, or 60/40, or any other ratio?) Non-fuel, discretionary weight is a value. Make it the same on both ends and I’m not sure how it matters whether a carry-on is a person one place and cargo another.

2 Likes

I do see your point. Yeah, on IF it is honestly just moving a slider down, etc.

Provided the number of passengers, I can indeed assume the total gross weight for passengers and cargo combined, and simply make sure that the combined weight is the same as that (# of PAX) x 230, and distribute that weight so it is equal.

There are still pretty insignificant, even with that method, smaller discrepancies, such as balancing out from the front and back. (ie. If I want to place a slightly heavier load in the front of the aircraft instead of the back to stop the nose from going up).

Right now, in IF, there is no choice on what section of the aircraft you place passengers in (I believe, correct me if I am wrong. I think they are just presumed to be in the center of gravity, for simulation purposes), so the cargo holds are the only way to really edit that.

I suppose another the alternative method is to drag only the cargo slot to simulate passenger weight, which would solve that problem. But that “defeats the purpose” of having passengers, I guess.
Why have simulation of passengers and cargo if you aren’t actually going to care, as long as the dead weight is there. Just my opinion. Lol.

Again, to reiterate, I do understand that there are ways of doing this that are almost as equally as accurate, however, I am just curious as to how I can calculate the most realistic cargo and baggage in IF, regardless of alternatives, in which case, you’d just need some cold hard conversions, and equations: which I’m trying to come up with.

Interesting approach, I hadn’t thought of that one (Sorry I’m writing paragraphs, it is a bit hard to get your point across in regards to this, haha).

This is after all, just something I was intrigued by, and was wondering if there was actually one “ideal” way of solving it. By no means is this a serious topic. Just something I was thinking about :)

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.