Hello everyone,

 

I'm trying to reconcile the results I get when I use the PMDG payload loader and the values that are found in the 737-600 aircraft.cfg in the weight and balance section.

 

Here's my understanding of that section. Each station that carries payload whether it is passengers or cargo is presented with a maximum weight allowed for that station, In the screen below the 737-600 aircraft.cfg indicates that the maximum for these five stations are as follows (in pounds):

For Cabin = 2625

Mid Cabin = 4025

Aft Cabin = 4725

For Cargo = 2800

Aft Cargo = 3300

TOTAL =17475

 

 

 

If I use the PMDG payload screen and choose SET FULL I get the following screen which shows 99.9% load with 129/129 pax and 5200 lb in the fwd cargo and 6000 lb in the aft cargo (almost double what the aircraft.cfg defines as maximums):

 

The FSX fuel and payload screen is equivalent to the PMDG screen as shown below with a total payload of 33,775 lb (nearly double what the cfg indicates as maximums):

 

 

Can anyone reconcile why this would be? Am I misunderstanding what the weight and balance section is showing? :wacko:

 

Regards,

Brent

Are you sure that the values in the aircraft.cfg are lb instead of kg?

 

I know there is still an error from about 5.000 lb in it, however I am not sure if 129 of 129 passengers are really 11.375 kg. If 129 passengers are less then 11.375 kg then it could be that the aircraft.cfg is kg while you set the FMC up to show lb.

 

But that's just a guess... :wink:

 

Jonathan

Jonathon,

There's a MSoft document that defines everything in the aircraft.cfg and it says 'pounds':

 

station_load.0

to

station_load.n Specifies the weight and position of passengers or payload at a station specified with a unique number, station_load.N. The first parameter number on each line specifies the weight (in pounds), followed by the offset relative to datum reference point. The addition of stations results in a corresponding change in aircraft flight dynamics due to the change of the total weight and moments of inertia.

 

Nice try though, I wondered that myself.

 

Brent

-station_load entries in aircraft.cfg are not maximum values, but current values, followed by their location (FSX uses point distribution model for both payload stations - somewhat acceptable, and fuel tanks - unrealistic)

 

That would be the first point of theory, now to the second point - there is a reason PMDG uses a custom loading procedure and there is a reason they ask you not to load the plane from FSX loadmanager.

Anyways the total load in loadmanager still fits. 11,200lbs of cargo and baggage, plus 175lbs per pax average weight (incl. carryon). There might have been changes in aircraft.cfg that can not be seen from payload settings window.

-station_load entries in aircraft.cfg are not maximum values, but current values, followed by their location...

 

Peter

Are you sure? They don't ever change when I've checked, If I use the PMDG payload editor and load pax and cargo, the values in aircraft.cfg don't change from the numbers I posted in the image at the top of this post.

100 sure. However not sure on how aircraft.cfg changes with the NGX.

 

In normal aircraft, it usually saves when you either load your plane or exit the flight. Or you can also edit it manually and see the pre-set value in payload manager change.

 

Also there is no limit to putting load in station, you can happily load thousands of pounds into pilot seat of the 172, of course, you will get a grossweight warning.

Well this post is about the 737-600NGX and the payload figures. My aircraft.cfg doesn't change. If anybody confirms that it does in fact change I would appreciate the info because it means something is amiss with my install. Also, if you use the PMDG interface to do a full load, could you confirm the same totals for payload that I have in the original post (i.e. 33,775 lb).

 

Thanks

Brent

My aircraft.cfg doesn't change. If anybody confirms that it does in fact change I would appreciate the info because it means something is amiss with my install.

 

Judging from the fact that total payload in FSX payload manager changes, I bet nothing is amiss.

Sure, but it still doesn't answer my question about the payload weights in the aircraft.cfg. I'm not having an issue with the plane - it was just a question to help me understand why there would be the discrepancy between figures in the aircraft.cfg, PMDG pax and cargo loader and the FSX fuel and payload screen. :lol:

... but there is no discrepancy... I dont follow...

As I pointed out in the original post, the discrepancy between what is defined in the .cfg file (17475 lb) and what can be loaded in the PMDG loader (33375 lb).

Fore mid andnaft cabin are where the passengers are right. In the aircraft.cfg those weights don't get written to it right away. They are held in a variable within the pmdg custom written subroutine and passed directly into fsx bypassing the cfg file.

 

 

 

DJuan Carter

DJuan

Thank you for the answer. So the figures that I have in my aircraft.cfg are just placeholders?

Brent,

 

The values in the aircraft.cfg are just static, "default" values, and in no way represent maximum payload or structural limits. Think of them as sort of a default loading mechanism that Microsoft uses for it's aircraft modelling. A lot of people jump in FSX planes and do not adjust payload and/or fuel levels, and by specifying some sort of default variable in the .CFG,it ensures the plane always has some sort of a load to it. A developer or end user can easily change the default values by editing those numbers in the aircraft.cfg to set some sort of a baseline. You could have it set to 0, and still load an infinite amount of payload in those fields and have the plane behave accordingly. They in no way represent maximum load levels. PMDG's load mechanism through the FS Actions pages alters this value inside FSX when you make changes, much the same way editing the payload through the Fuel/Payload menu does, but, as the ones in the aircraft.cfg are "default' values, every time you re-load the plane, those baseline values reset as the "active" payload. Changing your payload via either method will not SAVE to the aircraft.cfg, they're only altered for a single session as you make changes to them inside the sim. So yes, they are in effect a placeholder. Don't concern yourself with them.

 

Andrew

Andrew

Thank you very much for the explanation. Now that I've looked at a few other aircraft.cfg files I see that the figures used in them are quite consistent with your description of station loading. For example the default MS Cessna 172 has several values of 0 in stations where passengers would sit.

 

There isn't any field in the cfg file that defines a physical max payload so I guess the best you can do is define how much payload is possible with a full load of fuel:

 

(max gross weight - empty weight) - full fuel weight = payload --> then adjust the payload depending on actual real world limits and the amount of fuel loaded that is possible without going over the max gross weight.(i.e. less fuel can mean more payload).

 

Thanks again,

 

Brent