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Take-Off Performance


David Katona

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Jordan Collins
2 minutes ago, Liam Carbin said:

Its already there, click the imperial button on the calculator 

you made my day lol thanks I didnt see that buddy!

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UPDATE: Available at http://wabpro.cz/A320/   Hey everyone, I am planning to publish my take-off performance calculation website in a few days. Figures are based on FCOM performance cha

Hi guys, I have enabled the W & B tab on the website. Right now kilograms only! First select engine type on the Take-Off tab, as different CoG envelopes apply. CONFIG: If you select a co

Just to show you guys what I am working on for the W&B page... This is rather for people who actually care about the balance   It will show the weight and balance positions and the limits. The r

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Kamil Juvat

@David Katona, I second an option to select optimum flap setting. Here's what the documentation says about optimum take-off configuration:

Quote

Each configuration is associated with a set of certified performance and it is, therefore, always possible to determine a Maximum Take Off Weight (MTOW) for each takeoff configuration. As a result, the optimum configuration is the one that provides the highest MTOW.

 

 

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Simon Kelsey
On 6/26/2018 at 5:18 PM, David Katona said:

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.

IRL A Big Airline's performance software outputs the configuration that provides the highest RTOW unless a specific configuration is requested.

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David Katona
8 hours ago, Simon Kelsey said:

IRL A Big Airline's performance software outputs the configuration that provides the highest RTOW unless a specific configuration is requested.

Thank you for that information Simon.

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Christoph Hackenberger

Something seems to be broken, everytime I want to Init WB or calculate Takeoff performance I get an error message: "Error occured, please try again!"

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David Katona
44 minutes ago, Christoph Hackenberger said:

Something seems to be broken, everytime I want to Init WB or calculate Takeoff performance I get an error message: "Error occured, please try again!"

Thanks Christoph for letting me know... It took some time to resolve it, but should be back to normal now.

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Christoph Hackenberger
7 minutes ago, David Katona said:

Thanks Christoph for letting me know... It took some time to resolve it, but should be back to normal now.

You are a legend! Thanks for the quick fix :D

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Igor Petrov
On 6/27/2018 at 11:39 PM, Simon Kelsey said:

IRL A Big Airline's performance software outputs the configuration that provides the highest RTOW unless a specific configuration is requested.

Interesting, the highest RTOW might not be the most resource-efficient configuration unless the aircraft actually carries it. I realize it is still more thrifty than TOGA, but yet it is more like using TOGA, than calculating the most efficient mode for a particular runway. On that note I recall watching aircraft taking off at Heathrow (or was it in Gatwick?) and I remember most of A320-A319 were actually lifting off somewhere in the middle of the runway rather than using the reasonable length of it to my surprise.  It was summer, the day was sunny and perhaps  just a little windy  )).  

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Timm Rehberg
3 hours ago, Igor Petrov said:

On that note I recall watching aircraft taking off at Heathrow (or was it in Gatwick?) and I remember most of A320-A319 were actually lifting off somewhere in the middle of the runway rather than using the reasonable length of it to my surprise.  It was summer, the day was sunny and perhaps  just a little windy  )).   

That could also be the case for the traffic-rush on these two mentioned airports.
The separation for the runway traffic is much higher if a A319-A320 is using the "full" runway than to lift off as soon as it can with a combination of flexing a bit the thrust.

Whats the rule for giving a landing clearence after a departing aircraft? Normally it should be ok to give a landing clearence as soon as its passing V1/VR point then, right?

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Riccardo_Parachini
Interesting, the highest RTOW might not be the most resource-efficient configuration unless the aircraft actually carries it. I realize it is still more thrifty than TOGA, but yet it is more like using TOGA, than calculating the most efficient mode for a particular runway. On that note I recall watching aircraft taking off at Heathrow (or was it in Gatwick?) and I remember most of A320-A319 were actually lifting off somewhere in the middle of the runway rather than using the reasonable length of it to my surprise.  It was summer, the day was sunny and perhaps  just a little windy  )).  


Well, at some places with many take off intersections, sometimes it’s inserted the most likely/the shortest one. In case you get it you are ready, otherwise you are using a conservative value.
Eg MXP 35L, most EZY crews insert performance for 35L FE intersection (2550m).


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Simon Kelsey
4 hours ago, Igor Petrov said:

Interesting, the highest RTOW might not be the most resource-efficient configuration unless the aircraft actually carries it. I realize it is still more thrifty than TOGA, but yet it is more like using TOGA, than calculating the most efficient mode for a particular runway. On that note I recall watching aircraft taking off at Heathrow (or was it in Gatwick?) and I remember most of A320-A319 were actually lifting off somewhere in the middle of the runway rather than using the reasonable length of it to my surprise.  It was summer, the day was sunny and perhaps  just a little windy  )).  

I should clarify that when I say "highest RTOW" that does include lots of flex... I suppose a better way of putting it would be the flap setting that gives the highest RTOW for a given flex (I think -- it all becomes a bit mind-bending when you start thinking about it too much!). This will depend to a large extent on second-segment obstacles.

Some airlines do "improved climb" which artificially raises the V speeds (thus resulting in a longer takeoff roll); I'm not sure the airline in question does that, though.

1 hour ago, Timm Rehberg said:

Whats the rule for giving a landing clearence after a departing aircraft? Normally it should be ok to give a landing clearence as soon as its passing V1/VR point then, right?

It depends... in the USA you can be cleared to land when you're about #8 on the approach!

The UK, however, works to the general rule that the departure must be airborne before the lander crosses the threshold (with the exception of special "land after" procedures at Gatwick and, I think, Stansted). Most of the rest of the world has a similar approach!

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Timm Rehberg
1 hour ago, Simon Kelsey said:

It depends... in the USA you can be cleared to land when you're about #8 on the approach!

But then with the info "monitor the frequency" or something similar, right?
I don´t understand how you can take the risk to clear someone to land when there is a that much risk of something to happen what could cause a go-around.
Americans..... :mellow::ph34r::D

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Igor Petrov
3 hours ago, Timm Rehberg said:

That could also be the case for the traffic-rush on these two mentioned airports.
The separation for the runway traffic is much higher if a A319-A320 is using the "full" runway than to lift off as soon as it can with a combination of flexing a bit the thrust.

But that would require coordination between FLTOPS and ATC of which I'm doubtful.

 

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Igor Petrov
1 hour ago, Simon Kelsey said:

I should clarify that when I say "highest RTOW" that does include lots of flex... I suppose a better way of putting it would be the flap setting that gives the highest RTOW for a given flex

That clarifies it then.

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David Katona

I have not moved the aircraft (A319) from the stand, as I was only figuring out the fuel index influence for the weight&balance. I have to say I am impressed :) Good job FSLABS! Probably not everyone will notice (or care about) the effect of fuel on the CoG, but it is spot on.

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Darren Howie
On 7/3/2018 at 11:02 PM, Timm Rehberg said:

But then with the info "monitor the frequency" or something similar, right?
I don´t understand how you can take the risk to clear someone to land when there is a that much risk of something to happen what could cause a go-around.
Americans..... :mellow::ph34r::D

The Americans are smart enough to realize that just because a crew has been cleared to land does not mean they are so stupid they would blindly land on a still occupied runway.

They seem to respect people flying a commercial airliner are smart enough to work out if something is so unsafe as to require a go around. I mean we have flown the thing half way around the world safely navigating storms etc but cant be trusted to do a go around because a runway is occupied...and even then ATC can still send you around.

Unlike the rest of the world who seem to believe a crew cleared to land would still land even with an aircraft holding on the runway.

It cuts the amount of radio chatter down significantly at already busy and it works fantastcally.

Airbus 12 heavy your number 5 cleared to land runway 8 right...Americans making life easy for generations...lol...Keeping it simple...

The ATC system has become a butt covering excercise telling people who continually have there butt in the wind how to cover butt..

 

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Darren Howie
19 hours ago, Igor Petrov said:

Interesting, the highest RTOW might not be the most resource-efficient configuration unless the aircraft actually carries it. I realize it is still more thrifty than TOGA, but yet it is more like using TOGA, than calculating the most efficient mode for a particular runway. On that note I recall watching aircraft taking off at Heathrow (or was it in Gatwick?) and I remember most of A320-A319 were actually lifting off somewhere in the middle of the runway rather than using the reasonable length of it to my surprise.  It was summer, the day was sunny and perhaps  just a little windy  )).  

Even a fully loaded A320 using max flex ie 70C in an IAE wont go close to using a full runway length at a 3000m runway.

The max legal reduction in thrust is only 25% so your still getting 75% of the engines rated thrust. So even at 77 Tonnes it does need an enormous amouunt of runway.

Now in the 330 we used to go over the runway end at Bangkok with 4000m runways at 233 tonnes at 60-100’ fully flexed dragging our butts into the night sky. The 32c and high humidity didnt help...lol

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Luca Casalucci

@David Katona, why don't you add the green dot output in the takeoff performance calculator? It would give the possibility to check if you inserted the right weight in the app like in real life

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Timm Rehberg

Random question: Between the CFM and IAE engines from the A319: how much is the general difference for the figures calculated?
I know the IAE are a bit more powerful so I reduce some points from the Flex temp  + 2-3 kts from the V-speeds.. but is this roughly calculate able :D

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David Katona
3 minutes ago, Chris Kreuzbichler said:

Is the website working for one of you?

I have my webservice provider looking into it. A few of their servers went down with file system issues, they are in the process of recovering them and everything should be back to normal shortly.

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David Katona
3 minutes ago, Dustin Pöppelmann said:

@Jack Finn thats not correct..  the IAE V2500-A5  have 2x 24,000 lbs  thrust & the CFM 56-5B6P  just 2x 23,500 lbs  thats the reason why u use higher flex temp's on the IAE's

FSLABS simulates the CFM56-5B7 at 27,000lbs on the A319, so in our case the CFM is more powerful than the IAE.

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Timm Rehberg

I cannot open the website!

 

Not Found on Accelerator


Description: Your request on the specified host was not found. Check the location and try again.

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David Katona
11 minutes ago, Timm Rehberg said:

I cannot open the website!

 

Not Found on Accelerator


Description: Your request on the specified host was not found. Check the location and try again.

 

1 hour ago, David Katona said:

I have my webservice provider looking into it. A few of their servers went down with file system issues, they are in the process of recovering them and everything should be back to normal shortly.

 

They're still working on it, sorry for the inconvenience.

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Florian Venus

Working now - and I want to take the chance and say THANK YOU very much for your work and effort! I worked quite some time as a load planner and your tool is really amazing. Hope to see more features in the feature :) Keep up the spirit

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Jack Finn
4 hours ago, Dustin Pöppelmann said:

@Jack Finn thats not correct..  the IAE V2500-A5  have 2x 24,000 lbs  thrust & the CFM 56-5B6P  just 2x 23,500 lbs  thats the reason why u use higher flex temp's on the IAE's

ok smart ass

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Xander Koote

@David Katona I am trying to modify the standard baggage weight to one I am more used to in Latin America. Here an average of 30 kilo's plus per passenger is not out of the ordinary. I am trying to modify the website URL with the .../?bag=xx as you previously mentioned. But no matter what figure I put, either 8 kilo's or 34 kilo's the random load always goes back to 14 kilo's per bag. Am I doing something wrong?

Cheers,

Xander

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David Katona

The speeds returned are from FCOM Vol 2 for the A319 IAE. Longer runways increase the speeds for improved climb performance. Try to compare the figures for a short runway and then a long one. Shorter runways and the lower speeds will be closer to what the MCDU would suggest, not taking the improved climb into account.

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Maurício Brentano
7 hours ago, David Katona said:

The speeds returned are from FCOM Vol 2 for the A319 IAE. Longer runways increase the speeds for improved climb performance. Try to compare the figures for a short runway and then a long one. Shorter runways and the lower speeds will be closer to what the MCDU would suggest, not taking the improved climb into account.

Hum, perhaps a typo on the result sheet then:

uk8oSXT.jpg

NI73rhK.jpg

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Stefan Langen
On 7/18/2018 at 6:38 PM, David Katona said:

The speeds returned are from FCOM Vol 2 for the A319 IAE. Longer runways increase the speeds for improved climb performance. Try to compare the figures for a short runway and then a long one. Shorter runways and the lower speeds will be closer to what the MCDU would suggest, not taking the improved climb into account.

Can you tell in which section you found the distances? I searched many FCOMs vol. 2 online but could only find tables for permissible TOW and FLX calculation and never any hint to runway distances.

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David Katona

I will send it to you tomorrow. I have never seen FCOM 2 without rwy distance flex figures, so I am curious :) 

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