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B77X

Assumed Temp too high for 77W

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I just purchased the 777 takeoff calculator tool, downloaded installer, then installed latest update. But the Takeoff calculator for the 777-300ER does not give correct figures based on the weights I enter. Using another program for calculation, using the 77X as a base, numbers are closer to safe figures for the runways selected. Using Toper I get a high temperature derate giving a large trim setting at takeoff and a tail strike on rotation. An example is LSZH I set runway 34 intersection E8, current winds 278/04, oat 10c, qnh 1020. Takeoff weight of 212000 in another takeoff program gives TO1-64c as the largest derate it is safe to use for this runway. But Toper gives me a number of TO1-70C. Entering this into the 77W will cause late rotation and tail strike due to large trim setting needed. Thank you for this program, please assist..

Edited by B77X

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20 hours ago, B77X said:

I just purchased the 777 takeoff calculator tool, downloaded installer, then installed latest update. But the Takeoff calculator for the 777-300ER does not give correct figures based on the weights I enter. Using another program for calculation, using the 77X as a base, numbers are closer to safe figures for the runways selected. Using Toper I get a high temperature derate giving a large trim setting at takeoff and a tail strike on rotation. An example is LSZH I set runway 34 intersection E8, current winds 278/04, oat 10c, qnh 1020. Takeoff weight of 212000 in another takeoff program gives TO1-64c as the largest derate it is safe to use for this runway. But Toper gives me a number of TO1-70C. Entering this into the 77W will cause late rotation and tail strike due to large trim setting needed. Thank you for this program, please assist..

Hello there and welcome to the forums.

I am aware of this issue and the fix is on the way. It is taking me some time due to high workload I am experiencing at my workplace. Please be patient.

Thank you for submitting your query.

Kind regards,

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5 hours ago, nixdevelopment said:

Hello there and welcome to the forums.

I am aware of this issue and the fix is on the way. It is taking me some time due to high workload I am experiencing at my workplace. Please be patient.

Thank you for submitting your query.

Kind regards,

Thanks for the prompt reply. Will look out for the release when you can.

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On 7/19/2016 at 3:00 AM, nixdevelopment said:

Please try out new 3.3.9 version.

Kind regards,

Thank you that version is giving me good numbers. Have a great summer. I plan to buy the 737 calculator later this month!

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It took me some time to re-build the calculation algorithm but it should give much more precise results now. Thank you for supporting my projects and helping to make TOPER better.

 

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On 8/5/2016 at 3:34 AM, nixdevelopment said:

It took me some time to re-build the calculation algorithm but it should give much more precise results now. Thank you for supporting my projects and helping to make TOPER better.

 

Thank you for this program! Do you plan on doing a takeoff calculator for the Airbus A32X series?

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4 hours ago, B77X said:

Thank you for this program! Do you plan on doing a takeoff calculator for the Airbus A32X series?

I could make one but I don't posses any performance data at the moment. Perhaps in the future I might be able to make one.

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Hey,

recently I updated to v. 3.3.13 and I noticed that the assumed temperature is a bit too high from what I experienced so far. For example, I'm on my way from LSZH to RJAA and I had the following figures for T/O:

 

VcMsMKwCSIOafVIEDsgrRg.jpg

 

With these figures, the takeoff was VERY close to the end of the runway. Also the V-Speeds seem to be very high given that rather low takeoff weight. From experience and what you can see in the spotting videos of Zurich, the 77W usually rotates at about the intersection of runways 16 and 28, but today it took me way behind the runway cross until I reached VR. In fact I became airborne within the TDZ of the opposite runway.

Could you have a look at the algorithms if there is everything okay? The last takeoff in KSFO also was very close to the end of the runway...if it helps, I always compare TOPER calculations to TOPCAT although TOPCAT only has the 77L and still is in beta, but still...here, TO1 was not possible according to TOPCAT and it calculated a TO with an assumed temperature of 38°C for the same parameters as above.

Edited by skyrock

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