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Michael Moe

Topcat and the 737-600

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Well i have a huged different in derated N1 between PMDG and TOPCAT with in this case the -600.TOPCAT TO2 and a derated N1 at 83,6% while PMDG is at 78.7%. It gives a V2 at 7-9knots differencies.I have made a Edit file of the 737-800 and reduced weight etc as in this http://www.b737.org.uk/techspecsdetailed.html in TOPCAT.The -800 is about right after starting the APU which i still dont get why it changes the N1%. Will it change again when i normally shotdown the APU before taxi?ThanksMichael

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TOPCAT only has performance information for the 700 and 800 versions of the 737NG. While the main noticable difference between the aircraft might be length, the different versions use different engines (mainly software differences). Thus don't expect the derates to be the same.Example:B737-600 CFMI CFM56-7B20B737-700 CFMI CFM56-7B26B737-800 CFMI CFM56-7B27

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thats one of the few gripes I have with topcat. Its the total lack of support when it comes to diffrent aircraft types. If I was freeware I would understand but as for payware its very poor.I really wish they would sort it out abit.

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Is there a tutorial anywhere that ties up TOPCAT with an aircraft, e.g.737,or 747, et al?

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Hold on...I think there's a gross misunderstanding of what's going on here related to APU operations on takeoff and derates...TOPCAT's mention of the APU being on or off is for whether or not you're going to run the APU for the Packs on takeoff or not. If you have the Packs on the APU, you have more available thrust coming out of the back of the engine, so you can de-rate the thrust more. That's it.The normal operation of the APU for engine start and elec power has no bearing on this calculation if you shut it down prior to takeoff. So, the option isn't asking you whether it's on or off, currently. It's asking you, will it be on during takeoff, and will you be running the packs off of it at that point.

thats one of the few gripes I have with topcat. Its the total lack of support when it comes to diffrent aircraft types. If I was freeware I would understand but as for payware its very poor.I really wish they would sort it out abit.
So you're saying that since you pay a lot for new cars nowadays, that they should include direct-connect functionality with all of today's smartphones? Just because you paid for a tool that calculates takeoff distances, it doesn't mean you paid for a tool that will calculate takeoff distances for all of your payware... You paid for what was displayed on the TOPCAT page when you bought it. Nothing more, nothing less. The fact that it's a lifetime license means you're getting more than you paid for when he adds in other aircraft. There's really nothing to gripe about. It'd be nice, don't get me wrong. I really want to have actual -600 support, but it doesn't mean I deserve it...

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So you're saying that since you pay a lot for new cars nowadays, that they should include direct-connect functionality with all of today's smartphones? Just because you paid for a tool that calculates takeoff distances, it doesn't mean you paid for a tool that will calculate takeoff distances for all of your payware... You paid for what was displayed on the TOPCAT page when you bought it. Nothing more, nothing less. The fact that it's a lifetime license means you're getting more than you paid for when he adds in other aircraft. There's really nothing to gripe about. It'd be nice, don't get me wrong. I really want to have actual -600 support, but it doesn't mean I deserve it...
Get real man. It really peeves me when people make comparisons like this. Compare software with software and the see how you get on with support. I am sure people would pay to get bits added if it was required but support for the program has been zip lately.

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The amount of data in TOPCAT is unprecedent, and so is the amount of work needed to integrate an aircraft type.Even if FPPM was readily provided to TOPCAT authors (who are now busy finishing the other project, PFPX), for example via the way of PMDGs (who I hear are fans of the program) Boeing connections, there is still no commercial basis for inclusion of 600 and 900. While 800 and 700 are the most popular options for the 737 in real life, and consequently in FS, 600 is especially an oddball in both realms, and there is only a couple of people that fly it primarily, even less so are TOPCAT users, or perspective users.Ask yourself, would you be willing to spend additional tens, if not hundred of dollars to offset the development cost for the author? Not to mention that there are other, more desired types, such as 777 (which will be even more desired as PMDG nears completition), AIrbus family, or E-jet family (the last two admittedly being problematic in regard to data sourcing, not having the likes of Boeings FPPMs available)

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Get real man. It really peeves me when people make comparisons like this. Compare software with software and the see how you get on with support. I am sure people would pay to get bits added if it was required but support for the program has been zip lately.
John, I don't understand where your aggression is coming from in regards to my earlier post. I am being real. I made a comparison with situations in two different realms entirely, intentionally, in order to show the insanity of the assertion. Software is business and so are cars. You get what you pay for, and you pay for what is there right now, and that's what I stated very clearly in my message above.You want software? Then I'll give you software:The poster was asserting that TOPCAT should be more wider ranging, simply because we're paying for it. That's just absurd, really, especially since the covered models are clearly listed on the TOPCAT page, and when new models are released, we generally even get them for free. It would be like me walking up to any aircraft developer here for FS and saying "you know, we paid for your aircraft software, it should be wider ranging and have more features. Get that sorted for me please..." That's not how business works. I have a product that's advertised as doing X, and you pay for it. If it does X, we're good. Just because you pay for said software doesn't mean it should do X, Y, Z, and probably A, too, even if they're all along the same function.There. Happy with a simpler metaphor in the same market sector? To be honest, it really doesn't matter. In the end, the original comparison or this one are a fully valid explanation of why the argument was absurd. You not understanding it, or refusing to do so has no bearing on its relevance.

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TOPCAT's mention of the APU being on or off is for whether or not you're going to run the APU for the Packs on takeoff or not. If you have the Packs on the APU, you have more available thrust coming out of the back of the engine, so you can de-rate the thrust more. That's it.
For what its worth, nearly right my friend. Packs on or off has nothing to do with thrust required (N1). I shall try to explain my thoughts, the target thrust (N1) needed for weight, runway length, pressure altitude and temperature is related to allow the A/C to reach less than V1 with sufficient runway length to stop and also to allow the A/C to continue takeoff at V1 on 1 engine and obtain 35ft over runway far end. ie. Balanced Field.By drawing bleed air from compressor to operate any pneumatic system(s) reduces energy available to drive N2 and more importantly N1 turbines. This shortfall of N1 is made up by moving thrust lever to burn more fuel increasing the energy until N1 thrust is obtained. The target N1 is acheived regardless off pack operation, APU operation or even engine bleed valve position. Following along these lines at target N1 there is no more or less thrust from the engines.On my bike now, only my thoughts and some facts, Assumed Temps for another day. This should produce some comments.RegardsDave Baggs.

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