API - MinFOB and MinFOD fuel - Nonsense fuel values

SimBrief API
1

Hi,

our VA’s 737 fleet is using minfob and minfod fuel values in thounsands of pounds.

However, when using the API, and sending these fuel values, it appears they are interpreted as kilograms, and not pounds (as instructed in the documentation).

https://www.simbrief.com/ofp/ofp.loader.api.php?airline=TVQ&fltnum=6717&callsign=TVQ6717&orig=LIEO&dest=LZIB&altn=&date=31OCT24&deph=12&depm=45&type=B38M&climb=250%2F280%2F78&descent=78%2F280%2F250&cruise=CI&civalue=40&fuelfactor=&reg=OK-SWF&fin=1J021&selcal=AJBG&acdata=%7B%22cat%22%3A%22M%22%2C%22equip%22%3A%22SDE3FGHIJ1RWXYZ%22%2C%22transponder%22%3A%22LB1%22%2C%22pbn%22%3A%22A1B1C1D1O1S2L1%22%2C%22extrarmk%22%3A%22NAV%5C%2FRNP2+COM%5C%2FACASII+DAT%5C%2F1FANS2PDC+SUR%5C%2F260B+ORGN%5C%2FLKPRTVSX+RVR%5C%2F175%22%2C%22maxpax%22%3A189%2C%22oew%22%3A%2297.05%22%2C%22mzfw%22%3A%22145.397%22%2C%22mtow%22%3A%22181.195%22%2C%22mlw%22%3A%22152.795%22%2C%22maxfuel%22%3A%2245.69%22%2C%22hexcode%22%3A%2249D418%22%2C%22per%22%3A%22C%22%2C%22paxwgt%22%3A168%2C%22bagwgt%22%3A26%7D&planformat=LIDO&units=KGS&maps=detail&taxiout=9&taxiin=4&flightrules=i&flighttype=n&navlog=1&etops=1&stepclimbs=1&tlr=0&notams=1&firnot=1&steh=1&stem=56&fl=FL&pax=183&cargo=0.698&contpct=0.05%2F5&resvrule=&taxifuel=&minfob=9.259&minfod=4.078&melfuel=0&atcfuel=&wxxfuel=&addedfuel=&tankering=&minfob_units=wgt&minfod_units=wgt&melfuel_units=min&atcfuel_units=min&wxxfuel_units=min&addedfuel_units=min&tankering_units=min&addedfuel_label=hold&cpt=Jan+Podlipsk%C3%BD&pid=0002&dxname=vAMSYS+Robot&manualrmk=&route=BATOX+L5+VALMA+DCT+NIKOL+DCT+ALIVO+DCT+VALLU+DCT+NIGSI+DCT+GASNA+DCT+KUVEX&find_sidstar=R&etopsrule=180&apicode=06cba28c7793c74aa3800b599c781234&outputpage=%2Fphoenix%2Fflight-center%2Fbooking%2F2294990&timestamp=1730377208

That returns a nonsense FOB ADD fuel of 3065 kgs in the resulting OFP
LIEOLZIB_PDF_1730377214.pdf (857.2 KB)

Could you please take a look, what could be wrong? Thank you!

2

So we have found out the culprit. Simbrief API now follows the weight unit selector even with regards to the fuel limits in the API, despite API documentation clearly saying that “All weights except the paxwgt and bagwgt values must be in thousands of pounds, but can be specified with up to 3 decimal places (in order to set precise values).”

Looks like someone had changed something without letting anyone know, or even updating the documentation…

3

This note was located under the “Note regarding Aircraft Data” section, and applies only to the acdata parameter. I have added some text to clarify this now though.

But this example is actually working correctly from what I can tell. minfob and minfod should be used to specify the minimum Fuel On Board at the gate, or minimum Fuel Over Destination at landing.

You asked for 9,259 kgs of minfob, so SimBrief added 3,065 kgs of FOB ADD fuel to bring your planned block fuel to 9,259. No FOD ADD was boarded because with the new planned block fuel, you are expected to land with 5,367 kgs, which is more than your provided minfod value of 4,078 kgs.

Best regards,

4

Hi, thanks for the explanation. But that means, that the sender of the request needs to adjust the units of each aircraft parameter based on the weight units, the pilot wants to use.

That’s a lot of preliminary computing before actually sending the request, and from the programming point of view, makes zero sense…

Using one generalized weight unit is a lot more sensible.

5

At risk of repeating myself and just to make sure this wasn’t missed, airframe configurations (the acdata parameter) use fixed units as I’ve said, you only need to convert the other ones. Which in theory should normally be user specified anyways.

Your point on generalized weights is fair enough, but this isn’t likely to change at this point I’m afraid.

Best regards,

6

Understood, but since the Fuel Planning rules (minfob, minfod, atd…) are usually company policy, then I see no real difference between these parameters and the acdata.

Thank you for the explanation however.