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Bill Rowe

TOPCAT within PFPX vs Export

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I have been seeing a difference in the calculations performed by TOPCAT if I use the "integrated" approach (Clicking "Take-off" while planning the flight) vs. the external approach (clicking "send" after the flight is released).

I have been using the Boeing 737-800 for the profile in PFPX and TOPCAT and have the correct registration in both places. I set up the aircraft profile to allow de-rated, assumed temp, and combination takeoff calculations.

When I use the integrated approach, the calculation ignores the possibility of de-rate and assumed temp and only gives me a full thrust takeoff. If I send the same info to TOPCAT externally, I can get an accurate calculation of an optimized thrust take-off (with de-rate and/or assumed temp).

Have I set something up incorrectly, or is this something that needs to be cleaned up for future versions of PFPX. I'd much rather do the calculations within PFPX rather than exporting to TOPCAT.

Thanks,

Bill Rowe

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Are you changing the weight in the internal program when you calculate the speeds? It defaults to max takeoff weight, not your actual weight.

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The first section (when you use TOPCAT within PFPX by clicking the Take Off button) is just to determine the Performance Limited Take Off Weight (PLTOW) for that runway/wind/temp combination. PFPX will then give you a warning if you are over that PLTOW when fuel is calculated.

The bit where you send the data to TOPCAT after releasing the flight (where TOPCAT itself actually opens) allows you to calculate the engine derates for takeoff.

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The first section (when you use TOPCAT within PFPX by clicking the Take Off button) is just to determine the Performance Limited Take Off Weight (PLTOW) for that runway/wind/temp combination. PFPX will then give you a warning if you are over that PLTOW when fuel is calculated.

The bit where you send the data to TOPCAT after releasing the flight (where TOPCAT itself actually opens) allows you to calculate the engine derates for takeoff.

Phil,

Thanks! Now I see how the process is designed to work (would be nice to have something in the Manual to walk through the whole planning process rather than just what each button does)

Having said that, I still think it would be useful to be able to take a released flight and compute takeoff speeds/derates etc. within PFPX rather than opening TOPCAT.

Bill

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