Quick q: when doing W&B for the BN-2 I see there are two baggege entries that both move the CG backwards so I know they’re both in the aft of the plane.
Why are there two baggage entries and what do they represent?
they simply represent 2 baggage areas in the rear section …
No more
Why’s that? What’s the point of splitting a single compartment into two entries?
Possibly to distribute the weight depending on your passenger load out.
Usually that kind of decision comes down to balance. If you just left that area as a “single” area, then you could possibly be out of balance by throwing too much weight in the rear and too little in the middle part of the area. If they make it two separate areas they can basically specify the max weight you can put in the rear area and be much more specific about the impact on the W&B computations.
Hope that’s not too much rambling while trying to spell out the reasoning behind it.
Regards
Well your answer assumes the two rear baggage areas actually have different cg moments. Do we know this is for sure the case?
I tried placing large weights in both and either of them and the cg seemed to move the same way: to the rear of the plane. It sure seems like they are both in the same location
I don’t have the W&B sheets for this plane, so not sure whether having the max weight allowed (minus pilot and fuel load, etc) all stuffed in the back of the plane has sufficient change in CG to put it out of balance. I don’t know how well the sim recreates the actual CG computations. But any movement further aft from the datum point causes a shift in CG. It’s just a matter of how much impact the shift causes. Move max weight (minus pilot etc) back six inches and you don’t have much moment change. Move it back four feet and you might have a real issue.
It’s just a general rule that most designers use to try and minimize the pilots opportunity to screw up the CG computations.
There’s all sorts of other factors that weigh in (e.g. floor reinforcement,etc) all those design considerations too.
So take the general rule for what it’s worth in any specific case.
Regards
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How could you not have a different arm if the two areas are in two different locations? If they are the same location, then all you’d need is to change the weight.
FS recognizes left and right as well as fore and aft for item CG locations, as does gravity in the real world.
that’s the question, are the in two different areas or not? there’s only a single rear luggage compartment. the options are:
- both luggage w&b entries are for the same location: so why split into two?
- they are for different locations: but what are the locations exactly?
As i said i experimented with putting different weights in both locations and the cg seemed to move the same, or if there was a difference it was minute
W&B locations are in the flight_model.cfg file
The weight stations are separated as you can see here …
The Aft-most area can only carry 150 Lbs where the more forward one can carry 250
this makes a combined total of 400 As per type certification
station_load.10 = 250, -3.50, 0.00, -1.75, TT:MENU.PAYLOAD.BAGGAGE, 6
station_load.11 = 150, -4.70, 0.00, -1.75, TT:MENU.PAYLOAD.BAGGAGE, 6
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awesome, thanks! this was the concrete info I was looking for here. It would be nice if the locations were labeled in the W&B with max weight so you don’t over encumber the far back position. but now I know this for future flights