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747-400 A/P Help

Designing a stable autopilot is one of the hardest things. Need help?

Re: 747-400 A/P Help

Postby Octal450 » Wed Jul 27, 2016 4:29 pm

@Thorsten
I like the 747-400, so I'll have a look at the FCS. Thanks

@AndersG
I will check that thanks.
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Re: 747-400 A/P Help

Postby swwon » Thu Jul 28, 2016 12:03 am

it0uchpods wrote in Wed Jul 27, 2016 12:36 pm:@swonn
The 747-8 is vertically to nimble. Laterally, it flies pretty accurately from what I can tell -- never flown an 747 or 747sim.

The issue with the 747-400 is that the FDM tries to emulate fly by wire, but I think that is not lovely to do in the FDM!!!!!!!!!!!!!!!!!!!!!!!!!!! (well, maybe you can, I don't know.)

My point is, my AP can't fly is, because when he does, he eventually put's full trim down, and the plane is still at 15+ pitch! So......

In a later version I plan to use the elevator, as per real life, and then have the trim adjust to keep the elevator centered.


My conclusion on the 747-400 is that it is unfinished. If someone decides to work on it, then maybe all this will be solved! (is someone? I don't know) The 747-8i is unfinished, but stable, so These things don't occur.

Josh

Well like I said, the "400" feels more realistic, (and I've flown a real 400 sim and I have plenty of buddys that have actually flown them for a living. It's am interesting coincidence what Thorsten said,because in comparison of the two, the "-8" DOES feel cartoonish to an extent. It maybe more stable, but the "400" feels more "complicated/sophisticated" of the two on FG, in its FDM. It really shows its weight, you can feel it. The -8 moves around just as agile as a 777, and it shouldnt.
Being as the -8 is the latest and greatest in real life and most "400" pilots are anxiously awaiting their company to start flying those, I find myself keep getting drawn back to the FG "47-400" after flying the -8 numerous times. Because to me, by hand, it flies more realistically. Plus I'm a huge fan.
I would love to be part of some type of effort to make this plane fully functional, but I've never been a programmar, so writing stuff is all new to me.
I also believe a large part of the task will be NOT watering the plane and it's dynamics down but keeping it as it is and enhancing the cockpit for the instruments to work properly and of course a working A/P, autoland and all that (I'm trying to teach myself how to do things, but it's a steep curve). The "Queen of the Skies" deserves some attention.
Last edited by swwon on Thu Jul 28, 2016 7:18 am, edited 1 time in total.
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Re: 747-400 A/P Help

Postby Lydiot » Thu Jul 28, 2016 12:58 am

I completely agree with swwon... 100%
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Re: 747-400 A/P Help

Postby Octal450 » Thu Jul 28, 2016 2:33 am

I agree as well.

Well, I've never flown 747 sims, only MD-11 sims.

I am not saying the 747-8 flies better than the 400. I don't fly 747s in FGFS, so no comment.

Did more research. Found the issue. My COG was -90! lol Once fixed, she flew amazing!

Well I think I'll give it a go. I got autoland on the way ;)

Josh
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Re: 747-400 A/P Help

Postby Thorsten » Thu Jul 28, 2016 6:03 am

If this is the 747-400 by Gijs it may be that the trim channel actually adjusts the horizontal stabilizer rather than bias the elevator position.


Looking into the FDM, this is indeed the case.
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Re: 747-400 A/P Help

Postby swwon » Thu Jul 28, 2016 7:27 am

@it0uchpads, I'm anxiously awaiting your results!
I know you're currently working on quite a few planes right now. Just curious, are you going to be able to have the cockpit A/P controls work properly also?
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Re: 747-400 A/P Help

Postby Octal450 » Thu Jul 28, 2016 11:19 pm

@swonn
Yah. But linking the PFD will take more time, I'm still just learning Canvas. I'll give it a go though!

I am trying to finish up ITAF V3, I hope to get Beta 4 out by the end of next week. Possibly with some autoland. I'm almost finished working out FLCH.

@Thorsten
Thanks for the confirmation on that, JSB is still jibberish to me. :)



I'll push it up to my repo as soon as I got it fully working. Still some issue with heading hold, he doesn't listen to the heading prop or lnav or loc, only happens on this plane? Possible bug in ITAF.

Josh
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Re: 747-400 A/P Help

Postby swwon » Fri Jul 29, 2016 2:08 am

Awesome!
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Re: 747-400 A/P Help

Postby Octal450 » Sat Jul 30, 2016 1:52 am

OK well I found the issue. It may take some time to solve. There is indeed a conflict in ITAF that I did not see when moving properties to my own folder. I don't know why it worked in other planes, maybe some properties were tied together somehow, and it's different in the 747-400. I'll need to rework some stuffs.

I'll fix it in Beta 4.

Josh
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Re: 747-400 A/P Help

Postby Octal450 » Mon Sep 26, 2016 7:34 pm

Me and berkut are working installing IT3.0.0M1B20 into the 747-400.

viewtopic.php?f=4&t=30378
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