I have been using SimBrief for a long time and have never had any issues until now. Same aircraft configuration as always but now the calculated weights are off. In the past I have matched these values withing a couple of pounds here and there, but now there is no way to predict the results.
It all centers around the cargo weight. I’ve uploaded two images SimBrief Input and SimBrief Output.
Input for Freight value = 9.2
Output for cargo value=12.7
These values used to match. Somewhere recently a change was made to display these values in 100’s of pounds instead of 1000’s of pounds. Understandable change. But somewhere there is a computational error that these values that should be the same are somehow not computed the same.
I’ve been playing with the numbers. It looks like the cargo number differs from input to output by a factor of 10 as far as the final calcs go. coincidently that is the exact change that recently happened to the way cargo is calced. looks like someone missed a decimal place.
This isn’t a bug. Back in January, the Cargo number on the OFP was updated to include the passenger baggage weight. Remember that by default, SimBrief adds 25kg / 55lbs of baggage per passenger. Before, that weight was not included in the Cargo line. Now it is.
Anything you add using the “Freight” option when planning your flight will then be added on top of that baggage.
You can customize this behavior by creating a custom airframe. If you’d like it to be like before, where passenger baggage was not included in the cargo figure, simply increase the passenger weight to 104kg / 230lbs (or any other weight you’d like) and set the baggage weight to “0”.
I understand the baggage verses cargo issue. I’ve read other posts that explain that. When I configure for baggage the total weight is displayed in hundreds of pounds. When I configure without baggage the resulting cargo weight is displayed in thousands of pounds. Resulting payload remained the same in both cases.
Maybe it’s better to look at specific examples in that case:
To recap, you had the following settings:
- Passenger weight (in airframe settings): 190 lbs
- Baggage weight (in airframe settings): 55 lbs
- Additional cargo (in flight options): 9.2 (i.e. 9200 lbs)
- Passenger count (in flight options): 160.
So given that, the passenger weight should have been: (160 * 190) = 30,400.
And the cargo figure on the OFP should have been: (160 * 55) + 9,200 = 18,000.
Therefore your total payload should have been: 30,400 + 18,000 = 48,400.
Except, in this case, some of the cargo had to be offloaded in order to respect the MLW at destination (146,300 lbs). This is why the cargo figure is lower than 18,000, and note how the LAW is right at the limit on the OFP (146.3).
Because of this, your OFP had the following dispatch remark on the first page to indicate that some cargo was offloaded:
PAYLOAD/CARGO LIMITED BY MLW.
If you still believe there is an error in the cargo figure on subsequent flights, please provide similar screenshots of the options and OFP for that flight and I’ll look into it as well.
Correct. Run the same weights as 245 lb with no baggage weight. I get 0.9 in cargo instead of 9.2. Payload remains the same.
Dan Bonenfant, PLS
308 Patio Place
Columbia, SC 29212