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Simicro

Which tool for take-off performance calculation?

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Hi all,

 

Until now I was using the assumed temperature (65°C) and flap settings () from the tutorial flight Maldives-Dubai for... all my flights! Yeah...  :lol: Believe it or not: I ran short of runway only once with the "Long Haul" Fuel preset in FS Actions (150 tons or something like that). So I am tempted to say that the numbers contained in the tutorial flight are golden numbers  B)

 

Seriously, now that I am more comfortable with the general operation of the 777 and have a better understanding of the concept of thrust limit for airliners, I want to make it to the next level (step by step ^_^ ) and select the right flaps and assumed temp according to the winds, runway lenght, altitude and so on.

 

I made some investigations and I've come up with:

 

1. THE MANUAL COMPUTATION click here

- That is not for me

 

2. UTOPIA 1.2 (Universal Take Off Performance Information), a freeware available in the AVSIM library (utopia12.zip)

- I like it because it's simple and straightforward

- Apparently it has a airport/runway database

- The only 777 profile available is for the PSS 777-200

 

3. TOPCAT click here

- The famous one everybody is talking about

- As I understand it is comprehensive and accurate

- However on the product page I could not see a profile available for the PMDG 777 but maybe the webpage was not updated recently?

- I don't like it much because it is overwhelmed with data

 

4. AURASIM click here

- Seems nice but it has been on "release soon" status since last october...

 

5. TOPER CALCULATOR TOOL - B777 click here

- Simple but lacks airport/runway database

- User Interface not as nice as just released TOPER CALCULATOR TOOL - B737 NG

 

I like nice, easy-to-use and straightforward interface and as a beginner I am not looking for a millimetric accuracy in the calculations. General consistency will be fine. Also, if a computational feature is already built in the PMDG 777 FMC I prefer to use it rather than use third-party.

 

Could you please advise me?

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3. TOPCAT click here
- The famous one everybody is talking about
- As I understand it is comprehensive and accurate
- However on the product page I could not see a profile available for the PMDG 777 but maybe the webpage was not updated recently?
- I don't like it much because it is overwhelmed with data

 

You don't like it much because it is overwhelmed with data?

 

What do you mean by that?  Remember that, when it comes to computing values, you're always subject to TRASH IN : TRASH OUT.  If you only give a program limited data, you're going to get a limited (less accurate) result.  While more data isn't always a good thing, it usually is.  Sure, it asks for a lot of information, but in doing so, it's going to give you a more accurate result.

 

It does have a profile for the 777 (it may still be only in beta, I'm not sure, but it's publicly available).  The profile isn't as accurate as it should be, but it's close enough for me.

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How is in the performance intitation page of the FMC. All parameters are there. People spend a great deal of time programming it to be as accurate as any FSXer will ever require.

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Not sure you guys are on the same page...

 

The FMC's calculations do not provide recommendations for derates or assumed temps, which, I believe, is the reason this thread got started.  So, Rendi's recommendations aren't quite accurate to that end.  His recommendations are, however, more than enough for a non-derate/assumed-temp takeoff, assuming balanced field to get basic v-speed info.

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@Kyle: I agree that a certain amount of data is required for a good computation. I will  give an example from PFPX (just to make myself understood): "overwhelming" is when you split the passengers weight into adults, children, infants... Yeah I know it's more realistic etc but it adds more data fields while a total passenger weight will do.


The FMC's calculations do not provide recommendations for derates or assumed temps, which, I believe, is the reason this thread got started.

 

Right!  ^_^

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@Kyle: I agree that a certain amount of data is required for a good computation. I will  give an example from PFPX (just to make myself understood): "overwhelming" is when you split the passengers weight into adults, children, infants... Yeah I know it's more realistic etc but it adds more data fields while a total passenger weight will do.

 

Which is why you can make an entry in the payload and baggage fields instead (payload - baggage = ???, yep)  :wink:

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It is not necessarily overwhelming because data has to be entered, but visually I mean.

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What you should do is use PFPX AND TopCat. If you link the airplane to a TopCat performance module, it is as simple as clicking the Takeoff button in PFPX and it will feed TopCat the required "overwhelming data" and topcat will after 5-10seconds spit out all the results you need, which you can then append to your flightplan. It literally is as simple as clicking a few buttons.

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It is not necessarily overwhelming because data has to be entered, but visually I mean.

What I do is skip the payload page of TOPCAT and go straight to the takeoff page, update weather for the airport, select runway and enter my takeoff weight. I leave the flap and thrust options at optimum, then hit calculate

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Hi Guys,

 

TopCat works for me and has the 777LR/F profile available by public Beta.

 

Have not run out of Runway yet on my takeoffs. :unsure:  

 

Kind Regards

Simon Ward

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I use PFPX + TopCat and enter ZFW from PFPX into Load page of TC, then  go to take off page etc etc.

There is an issue in TC beta for the T7, it will not generate TO and Landing  report.

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Thank you all for the info on public availability of the 777LR/F profile, the skipping the load page on TOPCAT and your practice experience.

 

I do not want to make a fancy choice so I will go for TOPCAT.

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What I do is skip the payload page of TOPCAT and go straight to the takeoff page, update weather for the airport, select runway and enter my takeoff weight. I leave the flap and thrust options at optimum, then hit calculate

I never thought of that. It will be a real time saver.

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