Weight of Passsengers - can it be changed?

[downscc 1,327]

Although I believe most flight crews would be mildly interested in number of pax, the only time they need to know is when declaring an emergency and the number of souls on board needs reported.  Also, carrying families going on vacation will be substantially different from carrying a college football team; therefore, the value that is important is the ZFW.

[SteveW 1,792]

So "168lbs is 12 stone in English which is a reasonable pax weight assuming a mix of male/female."

Let's say we have 100 passengers average 168lb... that's 16800lb. If the plane desires 185lb passengers, 16800/185 = 91 passengers averaging 185lb if we wish.

Simply apply the calculation to arrive at the numbers we desire for the software

[SteveW 1,792]

...so if we look in the [WEIGHT_AND_BALANCE] section of the aircraft cfg we notice there's no indication for the number of average passengers because it's not relevant for the calculations of flight within the current sim. We can alter the loading of each section that to a degree alter the balance of the aircraft. All along we simply assume our own desired average passenger weight and make the proportional adjustment for the desired software planning.

[Ray Proudfoot 8,947]

Steve, thanks for the tip but as others have said the pax numbers can be ignored really. You’ll probably know PFPX also adds children and infants to the random pax load so entering your formula still has flaws.

And baggage is extra! Closer to 199 lbs per pax.

I’ll just go with the ZFW. 😊

[SteveW 1,792]

There's no flaws in that calculation of course. We simply extend it into groups if we wish to separate children. it's the same anywhere in the known universe.

[Ray Proudfoot 8,947]

8 minutes ago, SteveW said:

There's no flaws in that calculation of course. We simply extend it into groups if we wish to separate children. it's the same anywhere in the known universe.

If it made a difference I’d consider it but after all’s said and done I’m hardly likely to need to know souls on board when declaring an emergency.  CG is handled by the aircraft so it really isn’t important.

[SteveW 1,792]

6 hours ago, Ray Proudfoot said:

If it made a difference I’d consider it but after all’s said and done I’m hardly likely to need to know souls on board when declaring an emergency.  CG is handled by the aircraft so it really isn’t important.

I'm not posting advice for you and I'm not selling any kind of advice to you. I wanted to expand on Kyle's answer a little as the question does come up occasionally. After all - it's you wanted know if you could put in the average weight that you desired somewhere, and that's basically what my answer does provide you, and you can take it into separate portions if you wanted to do children - your suggestion not mine. No need to worry about it if you've got the better understanding of it now of course.

[SteveW 1,792]

9 hours ago, Ray Proudfoot said:

CG is handled by the aircraft so it really isn’t important.

By the way, the weight distribution affecting the aircraft asserted within the aircraft cfg in the [WEIGHT_AND_BALANCE] section isn't to control the balance of the aircraft trim in flight. This is where the software defines how much weight is available to add to each payload area within the aircraft. It is of critical importance to how the aircraft is set.

[vc10man 732]

14 hours ago, Ray Proudfoot said:

GSX

That herring, again!

14 hours ago, Ray Proudfoot said:

tweak PFPX fuel calculations

Same here

[chumley 0]

On 1/29/2019 at 9:35 AM, Ray Proudfoot said:

Steve, thanks for the tip but as others have said the pax numbers can be ignored really. You’ll probably know PFPX also adds children and infants to the random pax load so entering your formula still has flaws.

And baggage is extra! Closer to 199 lbs per pax.

I’ll just go with the ZFW. 😊

Hi Ray

I used to use PFPX but my 'airline' was Adults Only and was much more pleasant environment where the only 'squawk' was a number in the FMC. 

I ditched PFPX when it was seemingly unsupported and moved to Simbrief. Haven't missed a beat since.

[Ray Proudfoot 8,947]

6 minutes ago, chumley said:

Hi Ray

I used to use PFPX but my 'airline' was Adults Only and was much more pleasant environment where the only 'squawk' was a number in the FMC. 

I ditched PFPX when it was seemingly unsupported and moved to Simbrief. Haven't missed a beat since.

Andy, a new version of PFPX came out recently and is supported. I particularly like how you can enter engine, temp and fuel usage into it to refine anticipated fuel consumption. How does SimBrief do on calculating accurate fuel loading?

[downscc 1,327]

6 hours ago, Ray Proudfoot said:

How does SimBrief do on calculating accurate fuel loading?

The flight planning tool is only as good at fuel planning as the quality of the aircraft performance and wind forecast data.  SimBrief looks better if it has better data, sometimes it does and sometimes not.  I don't use SimBrief because PFPX has a much more complex set of tools for such things as EROPs and re-dispatch planning, and because SimBrief is a freeware so by definition it is intended for gaming.

[SteveW 1,792]

The actual fuel used on flights by the actual sim plane is so important in the sim it's good news to see that in other planners now. The most important metric is the actual Range of the aircraft and is usually shown in the specifications or on the website as an important value.

The range can be estimated quite easily for a sim plane by loading the plane with a working amount of fuel and payload, and placing at working altitude and speed in the sim. Allow it to stabilise and take the fuel difference over a couple of minutes. This quick check produces quite a close value for Range and puts us in the ballpark very quickly. Try it on a few planes and compare results. Knowing the Range of the plane allows us to quickly estimate how far we can comfortably fly in a certain time, perhaps the short time we have available for a sim flight today.

[SteveW 1,792]

..the way folk fly in the sim is extremely diverse, some don't even fly the plane just work out the details, others get up in the morning, grab the keys and go. Using full-on planning with the PDMDGs is great fun, how many actually check the fuel used and the time taken and compare to the calculations is not so certain but is equally rewarding. That's a bit like preparing for a holiday rather than for a day at work and so for many more flights I like to just get up and grab the keys and go so a good appreciation of the true performance of the sim plane is what I like to get into..

[Ray Proudfoot 8,947]

8 minutes ago, SteveW said:

Using full-on planning with the PDMDGs is great fun, how many actually check the fuel used and the time taken and compare to the calculations is not so certain but is equally rewarding...

I’ve been using the utility supplied in PFPX to fine tune my fuel figures. It’s reasonably close now to the calculated amounts for each waypoint.