Aircraft weight and payload question
I'm hoping that someone can clear up my confusion over aircraft weights in the aircraft.cfg and those in an aircraft text file held in the Types subfolder under CDU.
Let's take the Project Opensky 747-400 as an example. The empty weight for this aircraft as shown in the aircraft.cfg is 299,000lbs. If I then add the payload of 98,000lbs it results in a ZFW value of 397,000lbs.
Now if I look at a 747.txt file in the Types subfolder the following entries are present...
NetWeight=440000
Payload=35000
Why is there such a large difference between the weights held in the aircraft.cfg file and those in the 747.txt file? Are these just arbitary values that are replaced when the user enters the actual ZFW? Or are all those calculations further down in the 747.txt based on the payload values above?
Is NetWeight the weight without adding payload? If I press the ZFW button on the CDU it presents a value of 440 suggesting it does not include payload. It should, shouldn't it?
I would like both sets of data to match but I'm reluctant to change either as they may impact adversely on performance and calculations.
I understand that ZFW is the sum of empty weight + payload but before fuel is loaded.
I'm sure when I enter a ZFW of 397.0 the correct CDU calculations will be made but I'd feel happier if someone could confirm this.
Any help would be appreciated.