More Cargo Problems

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PCD001
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More Cargo Problems

Post by PCD001 » Mon Jul 12, 2010 3:47 am

I'm unable to get the cargo weight up to what I think it should be.
This is the pirep :-http://www.fsairlines.net/index.php5?st ... us2=logged
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Please note the cargo weight carried was 4185kg.
However according to my calculations it should be 4465kg (I've taken pax weight as 77kg per pax + 25kg luggage = 102kg):-

These are the figures, please tell me where I'm going wrong :-
aircraft data for MD88 :-
DOW 35369
MZFW 55338
MTOW 67810
Available Cargo space 8609
Available payload = 19969 (MZFW-DOW)
Flight details :-
Pax = 152 x 102(pax + luggage) = 15504
Space for Cargo = 19969-15504 = 4465 (8609 available on MD88)
Fuel = 6881

Take off Data
TOW = (Fuel) 6881 + (DOW) 35369 + (Pax&Luggage) 15504 + (Cargo) 4465 = 62219 (So I'm within MTOW)
Why was the Cargo limited to 4185 ?
Bob
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CAPFlyer
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Re: More Cargo Problems

Post by CAPFlyer » Mon Jul 12, 2010 2:25 pm

Baggage is calculated separately from passenger weight. You need to look at the briefing document before starting a flight. It breaks out the weights for you. I will guarantee that it adds up.
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PCD001
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Re: More Cargo Problems

Post by PCD001 » Wed Jul 14, 2010 2:23 am

Hi Chris,

Thanks for that. I've got the details for the briefing and the aircraft :-
Aircraft :-
Image

Briefing
___________________________________
PIC Bob Wright Date 06/23/2010
Rating Senior Captain Document FN720855

Origin YBTL Departs 04:51
Destination AYPY Arrives 06:57
Flightnr. PDA1211 Aircraft MD88 / P2-PDE

Distance NM 590
Route YBTL SWIFT R346 MABRO DCT AYPY
Remarks Load Minimum Fuel

Cost Index :50 Passengers 152
Passengers T 12.5 / 18.240$ ZFW T 55.1
Baggage T 3 DOW T 35.4
Cargo T 4.2 / 14.015$
_________________________________________________

I'm afraid I still don't see how it adds up ?.
There are things that I'm not sure about on the briefing :-
What affect does cost index 50 have on the calculation ?

Anyway here we go . . . .
As you can see the pax number is 152.
In previous threads the weight per pax was 77kg so this should be (152 x 77)= 11,704kg but the briefing has 12,500kg ? How has that been calculated ?
Pax Baggage should be (152 x 25kg) = 3,800kg but in the briefing its Pax Baggage is 3,000kg.
Then there are the aircraft weight differences
DOW in Briefing is 35,400kg, but on the FSA Aircraft list its 35369 kg - OK that's less than 1% difference.
ZFW in Briefing is 55,100kg, but on the FSA Aircraft list its 55338 kg - 238kg difference ?? <<-- this could be the difference ??
So . . . how is 4,200kg (4185kg) of Cargo arrived at ?
Working it out it still comes out at 4465kg
Of course on other flights with other aircraft the difference is more pronounced sometimes up to several tons.

I'm being very precise with the flight planning, as I'm trying to eek out the best possible performance using Pax/Cargo trade-off's and if I cannot find out how the calculations/figures are arrived at I'm not going to be able to do this.

Is there somewhere where the calculations are written out, or would I have to PM Konny ?

Thanks for your help thus far Chris.
Bob
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Re: More Cargo Problems

Post by CAPFlyer » Wed Jul 14, 2010 5:19 am

My understanding is that pax weight is 82kg/pax (about 180 pounds), which is close to what the real world airlines use. I'm not sure where you got the 77kg/pax from because I don't remember ever seeing that number.

Secondly, realize that the briefing rounds the numbers. I'm not a huge fan of it, but it's setup to look like a real world dispatch sheet.

The "Cost Index: 50" is irrelevant. If we had it setup, it would represent the FMS "Cost Index" setting to use for the flight. There is a plan to potentially add the required feature into the system at some point to allow for realistic Cost Index calculations for aircraft which are equipped with an FMS or which the user has added an FMS to, but until then, it's just "Window Dressing" and nothing more.

Finally, can you PM me a screenshot of the flight entry screen? I want to look at how you have that specific flight setup to see if that might explain it.
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PCD001
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Re: More Cargo Problems

Post by PCD001 » Wed Jul 14, 2010 3:48 pm

Thanks Chris,

I got the weight for PAX weight from Joe's post here :-http://www.fsairlines.net/forum/viewtop ... ght#p27126
Which indicates thats PAX+bags = 102kg and as their baggage is 25kg I took one from the other and got 77kg for each pax.
Any how I'll take this to PM - Thanks.

EDIT - After a lot of checking.

You are correct - the Pax weight is ~ 82kg.
Now is PAX + Bags still 102kg as per Joe's post or is this now 107kg ?
Looks like its still 102kg, so does that mean that the pax baggage is now down to 20kg per pax ?
Purely rhetorical Chris - I'll get the answer on your PM.

Cheers
Bob
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Re: More Cargo Problems

Post by CAPFlyer » Wed Jul 14, 2010 5:59 pm

You don't need to take the thread to PM. I just wanted that one screen (which I explained again in the PM reply) via PM. I don't want you posting that information directly because I don't want other VA's seeing how you're setting up your flights not just because I don't think you should have to share it (on principle) but it tends to cause a lot of "discussion" about how flights are setup by individual VA's and that's just not needed here.

If you send me that one image via PM, then I'll continue the thread here as to resolving the issue.

Also, I'm not sure where Joe got that number, but when we released FSAirlines, the Pax Weight was 82kg + 25kg of bags. We've always had it there because that equals 180 pounds per passenger and 55 pounds of baggage, which is what the "standard" weight of passengers was for load planning purposes with the real world airlines at the time that we setup the program. They've now increased the standard passenger weight, but we have decided not to change them at this point.
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PCD001
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Re: More Cargo Problems

Post by PCD001 » Wed Jul 14, 2010 8:36 pm

Thanks for the help.
If I use the figures of
Pax weight = 82kg
Pax Baggage = 25kg
Then I end up with a cargo weight of 3,705kg which is now well short of the FSA calculated weight of 4135kg. Strange.
Screeny sent.
Bob
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Re: More Cargo Problems

Post by CAPFlyer » Thu Jul 15, 2010 12:14 am

Well, I must admit that I'm a bit mystified as to why you didn't get a full load of cargo unless there was something else going on that I can't see (like your pilot reputation was a bit low or your VA's reputation was a bit low) that was causing the reduction. I know that there is a slight limiting of payload during your probationary period, but that wouldn't explain why the flight before it you had a full load of pax and cargo.

I think we'll just have to chalk it up as an odd bug.
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PCD001
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Re: More Cargo Problems

Post by PCD001 » Thu Jul 15, 2010 1:33 am

Thanks for checking this out Chris,

I'm still 117 out of 120 in reputation, so that may be it.
I'll try a larger aircraft later on (MD11) and see how this goes, the variation should be bigger so its probably easier to see where I'm going wrong.

Thanks again.
Bob
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The "New" Cheap Fuel Operator . & . 'T' Tail Fan !!
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