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Take-Off Performance


David Katona

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David Katona
6 minutes ago, Stu Antonio said:

This worked quite well, thank you.
I can even put in zfw AND pax in simbrief (it calculates the payload accordingly to match the zfw, which then differs from the one on your website. I guess simbrief calculates the baggage in a different way than you do, but I don't mind).
 

I randomized the loads on your website first, giving me 101 pax and 89 bags. But is it realistic that some payload compartments stay empty? 
(I used to calculate the loads with TOPCAT before, where it distributed the payload across all four compartments quite equally....) 

Stu

 

Depends on the airline. Low cost carriers would not carry cargo, and have a loading policy for the bags. You may utilise more (or all) of the holds if you have cargo and mail, but with bags only, unless very high load, it is common to leave holds empty. I remember the 737s had a policy of 70% and 30% bag distribution between fwd and aft holds, the airbus tends to be different in this I found.

By the way, I always found the amount of deadload generated by some other applications to be unrealisticly high on most occasions, but I am only basing that on the airlines I used to dispatch myself. Other people who worked at bigger airports with more cargo/mail might disagree.

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Stu Antonio
2 hours ago, David Katona said:

Depends on the airline. Low cost carriers would not carry cargo, and have a loading policy for the bags. You may utilise more (or all) of the holds if you have cargo and mail, but with bags only, unless very high load, it is common to leave holds empty. I remember the 737s had a policy of 70% and 30% bag distribution between fwd and aft holds, the airbus tends to be different in this I found.

By the way, I always found the amount of deadload generated by some other applications to be unrealisticly high on most occasions, but I am only basing that on the airlines I used to dispatch myself. Other people who worked at bigger airports with more cargo/mail might disagree.

I asked a captain-friend of mine who's on the job right this moment, and he sent me a pic of their LS. It's an A319-inner-EU-2h-flight. So  just for reference, they have 146 pax with 124 pieces of baggage, loaded into hold 1,4 and 5 (30/75/19). BTW, if I put theese figures into your calculator, it tell's me "out of balance", but I'm sure there is more to it than just copying numbers :)

As I can enter the amount of pax into your tool myself, is there a way to enter the amount of bags and let the system distribute it over the CPTs? 

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David Katona
21 minutes ago, Stu Antonio said:

I asked a captain-friend of mine who's on the job right this moment, and he sent me a pic of their LS. It's an A319-inner-EU-2h-flight. So  just for reference, they have 146 pax with 124 pieces of baggage, loaded into hold 1,4 and 5 (30/75/19). BTW, if I put theese figures into your calculator, it tell's me "out of balance", but I'm sure there is more to it than just copying numbers :)

As I can enter the amount of pax into your tool myself, is there a way to enter the amount of bags and let the system distribute it over the CPTs? 

If you tried that with the a319, the balance calculation has not been added yet, I need the aircraft to be released for that :) and cabin sections are different per airline, so their index influence is also different. 124 bags I would load the same way, yes. It is the same policy as one of the low costs in Germany. 

 

I will think about entering total bag and distribution. But as I said, distribution is operator specific. I can apply one that I like, but others might not :) 

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Jeremias Marco Harsono
6 hours ago, Stu Antonio said:

Hi there,

can someone give me a workflow for this cool tool together with simbrief? I can't seem to figure it out....

I used to plan my flights in simbrief, using random pax-loads.

What I get:
- Route
- Total amount of pax
- Total payload weight (luggage)
- ZFW
- Block fuel
- TOW

What I don't get:
- Distribution of pax and deadload
- CG
- Stab trim

So something's always missing,  no matter wich tool I use first.

Simbrief first -> I don't get the needed deadload-distribution for the Perf-Tool, and there's no option to enter ZFW in the tool.

Perf-Tool (weight page) first -> I don't have the Block-Fuel yet. AND there's no option to enter the total payload distribution seperately in simbrief.

How do you guys handle this? 

 

BG

Stu

 

What I do is this:

 

PERFORMANCE TOOL (PAYLOAD PAGE)

-Get randomized load then click INIT (without fuel load) and get ZFW

 

SIMBRIEF

-Do as usual, but don't change payload settings except for setting the ZFW the same as the one from the performance tool

-Get briefing

 

PERFORMANCE TOOL (PAYLOAD PAGE)

-Input fuel load then click INIT again to get updated payload

 

PERFORMANCE TOOL (TAKE OFF DATA PAGE)

-Do as usual

 

Center of gravity, trim, and load distribution is given in the performance tool. Just follow the steps.

 

This is not the most accurate method as I have no real world reference, feel free to make corrections.

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Jeremy Grimaud
19 hours ago, David Katona said:

By the way, I always found the amount of deadload generated by some other applications to be unrealisticly high on most occasions, but I am only basing that on the airlines I used to dispatch myself. Other people who worked at bigger airports with more cargo/mail might disagree. 

I agree. Based on my experience in Europe with A320s, It's unlikely to exceed compartment weight limitation. For a volumetrically full hold, loaded weight is most of the time 50% of compartment maximum permissible weight. It may be possible to be higher with dense/heavy cargo, but this is not quite common where I work.

Actually, I exceeded only one time a compartment limitation with the cpt5 on a A319. It was a route inside Europe to the hub of the carrier, where almost all passengers were transiting at the hub for flights going to Africa (these pax have a lot and heavy bags). Therefore even if I had still volume available on cpt5 to load some bags, I had to offload them to meet the cargo weight limitation, which is about 1500kg for the A319 cpt5.

Long story short. Cargo holds are most of the time volume-limited rather than weight-limited.

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Igor Petrov
On 6/15/2018 at 10:36 AM, David Katona said:

@Stu Antonio I just usually come up with the load on my website, get the ZFW without fuel (INIT without fuel figures entered). Then I use that ZFW on simbrief to get the flight plan. The whole point of that part of the website is the loadsheet capability, so I don't see the point of adding changeable ZFW on the site

David, this was mentioned and asked for earlier in this thread to make it changeable as many VAs require (or just advise) you to fly a certain ZFW. So could you look into this?

Many thanks!

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Igor Petrov

Guys, any idea how to stop GSX redistributing the load (when loading its PAX and Cargo) and therefore changing CG% values even after the numbers are preset in A320's  Options\Payload page, that I usually do based on  David's Performance Calculator? Or is it like LMC simulation as was discussed a couple of posts before? ))

Thanks. 

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David Katona
1 hour ago, Igor Petrov said:

David, this was mentioned and asked for earlier in this thread to make it changeable as many VAs require (or just advise) you to fly a certain ZFW. So could you look into this?

Many thanks!

If they tell you the ZFW, then isn't the weight and balance part of the website obsolete? I can sure add it, but I don't understand what is the use of it at all then. Please elaborate, so I can develop accordingly to fit the requirements :) Just out of curiosity, why do they do that, the virtual airlines? Surely there should be a tolerance of a few hundred kilos? Even in real life there is, think of LMCs and stuff.

1 hour ago, Igor Petrov said:

Guys, any idea how to stop GSX redistributing the load (when loading its PAX and Cargo) and therefore changing CG% values even after the numbers are preset in A320's  Options\Payload page, that I usually do based on  David's Performance Calculator? Or is it like LMC simulation as was discussed a couple of posts before? ))

Thanks. 

I don't think you can... I enter the weights once GSX stopped screwing up the figures. Basically part of my before start flow.

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David Katona

A different loadsheet will be added in the next release as well, so three different formats will be available:

1784884873_ScreenShot2018-06-16at20_13_42.png.db4f231c18e7e8c794a24497897500b2.png

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Igor Petrov
41 minutes ago, David Katona said:

If they tell you the ZFW, then isn't the weight and balance part of the website obsolete?

No, just make your tool distribute the weights randomly as it likes within your parameter limits but based on 1) given (changeable)_ZFW; 2) given (changeable)_number of PAX. Is it possible?

Thanks.

 

Edited by Igor Petrov
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Igor Petrov
50 minutes ago, David Katona said:

I don't think you can... I enter the weights once GSX stopped screwing up the figures. Basically part of my before start flow.

I've asked about this on their boards and am waiting for the response.

Here:

http://www.fsdreamteam.com/forum/index.php/topic,17975.msg125570.html#msg125570

 

 

Edited by Igor Petrov
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David Katona

Another new thing coming in the next version is an LMC generator. It generates a random PAX and bag LMC figure, but this can also be entered manually. Also, if the bag count if fairly low compared to the total number of passenger and if the cabin is quite full, it will randomly generate additional bags as LMC to simulate offloaded cabin bags.

1911077468_ScreenShot2018-06-17at18_17_29.thumb.png.b3f1836d7b3998764575ac8a5acd12a5.png

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Riccardo_Parachini
Another new thing coming in the next version is an LMC generator. It generates a random PAX and bag LMC figure, but this can also be entered manually. Also, if the bag count if fairly low compared to the total number of passenger and if the cabin is quite full, it will randomly generate additional bags as LMC to simulate offloaded cabin bags.
1911077468_ScreenShot2018-06-17at18_17_29.thumb.png.b3f1836d7b3998764575ac8a5acd12a5.png

Amazing!! Thanks David!!


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Ayush Roy

Wow, crazy work!

A stupid request David: would it be possible to get the website with a black background, like on real EFBs? :) I had seen one of your photos with the same great tool...and it looked exactly like a real EFB!! 

EDIT: something like this: 

Thanks

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David Katona
13 hours ago, Ayush Roy said:

Wow, crazy work!

A stupid request David: would it be possible to get the website with a black background, like on real EFBs? :) I had seen one of your photos with the same great tool...and it looked exactly like a real EFB!! 

Thanks

I have been thinking about that, bit more difficult than just flipping the background colour, because that looks ugly. But surely rethinking the design is on my list.

I am adding a few default options, but as I don't want to fiddle with cookies or login page, the actual link will have to be changed in the bookmarks, like this one which would make the page default to A319:
http://wabpro.cz/A320/?ac=A319

 

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M_i_k_e_V_o_g
19 minutes ago, Igor Petrov said:

Unfortunately Virtuali is not interested to dig in the issue at all.

Perhaps FSL could comment on it?

Thanks.

 

I'd *assume* virtually is right.

As he has no access to the code, he can't determine how the A/C redistributes the load and that's probably something the FSL bus is doing on its own.

What I don't understand is, how exactly do YOU expect it to work? If you wait a bit longer and enter your figures AFTER the boarding is finished, then you'll get what you wish for...

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Igor Petrov
6 minutes ago, M_i_k_e_V_o_g said:

I'd *assume* virtually is right.

As he has no access to the code, he can't determine how the A/C redistributes the load and that's probably something the FSL bus is doing on its own.

What I don't understand is, how exactly do YOU expect it to work? If you wait a bit longer and enter your figures AFTER the boarding is finished, then you'll get what you wish for...

C'mon, I just don't want FSL A320X's load distribution get affected by GSX connection (whatever it simulates there).

I agree virtuali doesn't have access but he could suggest some simconnect link or smth else, he knows better what strings his GSX pulls internally in the sim.

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M_i_k_e_V_o_g

Igor,

I  understand what you're saying. The bottom line though, is that one way or another YOU will need to punch in those numbers. the question is only about the timing...

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Igor Petrov
On 6/16/2018 at 9:13 PM, David Katona said:

I enter the weights once GSX stopped screwing up the figures. Basically part of my before start flow.

I don't want my preset loading numbers in MCDU's Options that I enter from TO Caclulator get screwed up after GSX.

Not a biggie but is it too much to ask as an Option at least? Since somebody should know anyway how they are manipulated behind the curtain.

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Riccardo_Parachini

Hi David!

I saw the introduction of LMC and that’s amazing. Can we put in a future release the change in weight and towcg due to LMC?
I’d like also to insert the lmc for C/M as I use a different weight for lmc due to bags...

Thank you for your great work!!


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Rob Jones

Pardon my ignorance, but I don't know what C/M means:(.

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David Katona
20 minutes ago, Riccardo_Parachini said:

Hi David!

I saw the introduction of LMC and that’s amazing. Can we put in a future release the change in weight and towcg due to LMC?
I’d like also to insert the lmc for C/M as I use a different weight for lmc due to bags...

Thank you for your great work!!


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Hi Riccardo,

The weights and CG change when you press INIT again after the LMC, so it'll recalculate everything and redraw the envelopes. Unless you would like to see how much the CG and weights changed in total (as it is required on one of the airlines LIRF in real life?). C/M LMC possible, I just need to find the space for it :) a quicker solution could be if I add an option to use different baggage weights, would that be useful for you?

13 minutes ago, Rob Jones said:

Pardon my ignorance, but I don't know what C/M means:(.

C/M means Cargo & Mail

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Riccardo_Parachini

Yep, adding the possibility to change baggage weight would be amazing!! Thanks David!

Yep, the absolute change due to LMC is required for some airlines. For instance one says that if LMC is less than +250kg/+/-2% recalculation of take off performance is not required...


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António Abreu

Congrats on the good job!

I would just suggest:

  • Try to rewrite the fields labels so they get more intuitive, specially for people trying to learn from simulation.
  • Would also move the MAC field to a dedicated line instead of having it in the same line labeled RTOW | ATOW.
  • The reason for having two runways is to allow for last minute" runway change, right? In this case, labels could read "Primary Runway" and "Alternate Runway" for instance.
  • NADP: I believe it to mean Noise Abatement Departure Procedure. Is this info relevant for the pilot (I don't really know)?

I know it's not easy to find a good balance between screen space/layout and labels but we can always try to improve it. Perhaps a small table at the bottom of the page containing the acronyms used in the fields could be useful to overcome some of the space/layout limitations and to coach more rookie people.

Anyway, keep it up, it is a very useful tool I use on every flight.

:)

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David Katona
4 minutes ago, Antonio Abreu said:

Congrats on the good job!

I would just suggest:

  • Try to rewrite the fields labels so they get more intuitive, specially for people trying to learn from simulation.
  • Would also move the MAC field to a dedicated line instead of having it in the same line labeled RTOW | ATOW.
  • The reason for having two runways is to allow for last minute" runway change, right? In this case, labels could read "Primary Runway" and "Alternate Runway" for instance.
  • NADP: I believe it to mean Noise Abatement Departure Procedure. Is this info relevant for the pilot (I don't really know)?

I know it's not easy to find a good balance between screen space/layout and labels but we can always try to improve it. Perhaps a small table at the bottom of the page containing the acronyms used in the fields could be useful to overcome some of the space/layout limitations and to coach more rookie people.

Anyway, keep it up, it is a very useful tool I use on every flight.

:)

Hi Antonio,

Thank you for your suggestion, I will review them all. By the way, the NADP is important, because you need to know that in order to set the correct acceleration altitude on the take off perf page in the MCDU, unless it matches the default setting for a particular airfield :) 

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António Abreu
3 minutes ago, David Katona said:

Hi Antonio,

Thank you for your suggestion, I will review them all. By the way, the NADP is important, because you need to know that in order to set the correct acceleration altitude on the take off perf page in the MCDU, unless it matches the default setting for a particular airfield :) 

Thank you for the info about the NADP. Always learning! Carpe Diem. :)

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Rob Jones

' Cargo & Mail ' - thanks David

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David Katona
On 6/21/2018 at 3:54 PM, Riccardo_Parachini said:

Yep, adding the possibility to change baggage weight would be amazing!! Thanks David!

Yep, the absolute change due to LMC is required for some airlines. For instance one says that if LMC is less than +250kg/+/-2% recalculation of take off performance is not required...


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For the time being you can change the baggage weights used by adding it to the URL, so if you bookmark the page with your preferred baggage weight saved in the URL, it should work always: http://wabpro.cz/A320/?bag=13

I will add a more user friendly option at a later point

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Riccardo_Parachini
56 minutes ago, David Katona said:

For the time being you can change the baggage weights used by adding it to the URL, so if you bookmark the page with your preferred baggage weight saved in the URL, it should work always: http://wabpro.cz/A320/?bag=13

I will add a more user friendly option at a later point

Thank you David!! It perfectly works!! As always thank you for the great job!!

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David Katona

I am adding another option for the pax and bag figures: standard. This is focused on Europe, so if origin or destination is a holiday location then the loadfactor would be higher, otherwise it is very random (I have dispatched flights - A320 - with 10 people on board, so low loadfactors do happen, couple of weeks ago PRG-TXL with 70 people on board in real life Easyjet, not unheard of... regardless, it could be full, it could be quite low). Number of children/infants will also depend on location, etc. Baggage weights: either defined in the URL, or random, so if you prefer piece concept than it needs to be added to the URL. As a dispatcher I usually received total number of bags and weight, so divided the two and I used that, so when you randomise the load, it will also define the baggage weight. Generally higher for holiday destination. Ideas are welcome.

1266938437_ScreenShot2018-06-24at21_25_41.png.20bdf3a0edb806c101716eef78cf1199.png

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Khoa Nguyen
On 6/20/2018 at 11:10 PM, Igor Petrov said:

I don't want my preset loading numbers in MCDU's Options that I enter from TO Caclulator get screwed up after GSX.

Not a biggie but is it too much to ask as an Option at least? Since somebody should know anyway how they are manipulated behind the curtain.

Totally agree, my MCDU payload always reset to incorrect value after boarding, I asked on the forum long time ago, to have an option to ON/OFF the GSX loading feature, but then no one replied me 

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Igor Petrov
Just now, Huy Khoa Nguyen said:

Totally agree, my MCDU payload always reset to incorrect value after boarding, I asked on the forum long time ago, to have an option to ON/OFF the GSX loading feature, but then no one replied me 

virtuali says GSX does not change anything intentionally. so it may be a side effect, or there's some intentional hook from FSL.

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Riccardo_Parachini
Forgive my ignorance but does LMC stand for Last Minute Change?
 
Stuart

Yes, usually it’s related to missing pax, rush bags or offloaded hand bags


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Kim Ruben Fjeldstad

A OPT Flaps Setting would be very nice!

I am missing that very much!

And an option to add Child and Infants! If you need some weights let me know, and I gladly send you for my airline I am handling for ;)

Fun with the DCS Loadsheet, since I print them out when I am handing over LoadSheet for the Airline I am working for!
And yes I am a ground handling Dispatcher/Gate Manager with all actions to be done, even if it is for the 737 and 787, and some Wetlease Airbuses ;) 

Looks like it is real!!

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David Katona
25 minutes ago, Roi Bennoun said:

Dobry den David, 

Thank you for this tool ! Any chance to add an option to select lower Flex temp ?

Dobry den Roi, I was thinking about that myself. I think for that to be useful the runway margin should also appear for the calculations though. I will have to look into that and will be added at a later time.

 

59 minutes ago, Kim Ruben Fjeldstad said:

A OPT Flaps Setting would be very nice!

I am missing that very much!

And an option to add Child and Infants! If you need some weights let me know, and I gladly send you for my airline I am handling for ;)

Optimum is the flaps with the lowest Flex? I don't really have real life reference as to how that is used. I would imagine (could be wrong) that there are airlines using Flaps 1 for all take-offs, unless performance requires different flaps setting. And there are airlines that would always use optimum flaps? You know, so far I am happy that we have runway and intersection lengths for so many airports thanks to the community here. I do not have obstacle data though at this time, which also affects TO Perf, so let's see what the future holds and once more data is available for the calculations, I will look at optimum flaps.

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Roi Bennoun
1 minute ago, David Katona said:

Dobry den Roi, I was thinking about that myself. I think for that to be useful the runway margin should also appear for the calculations though. I will have to look into that and will be added at a later time.

Dekuji ! :)

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Kim Ruben Fjeldstad

OPT Flaps is based on the weight, runway, temperature, qnh, weather to say something :)

Now we just have to wait for FSL to release their A319 and we can start using this for full!

 

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