Board index FlightGear Development Aircraft Cockpit development

747-8 in the cockpit

Discussion about creating 2d and 3d cockpits.

747-8 in the cockpit

Postby Jabberwocky » Wed Apr 02, 2014 3:36 pm

Hello,

is there a veersion of the 747 with an all in ockpit usable A/P? Like in the 777s? You know, pressing switches and turning knobs with the mousewheel instead of using the menu A/P? And if not, how hard is it? Seriously, I have no idea.

J.
Jabberwocky
Retired
 
Posts: 1319
Joined: Sat Mar 22, 2014 7:36 pm
Callsign: JWOCKY
Version: 3.0.0
OS: Ubuntu 14.04

Re: 747 in the cockpit

Postby tikibar » Thu Apr 03, 2014 7:28 am

You could try this version of the 747-8i/f. Its AP panel is fully functioning. https://github.com/dogsaysmoo/747-8i/archive/master.zip (change the name of the extracted folder to 747-8i.)
Last edited by tikibar on Mon Jul 14, 2014 12:18 am, edited 1 time in total.
Boeing 747-8 (rename folder to 747-8i)
Boeing 757-200/300 (rename folder to 757-200)
Boeing 767-300/ER (rename folder to 767-300)
McDonnell Douglas MD-11 (rename folder to MD-11)
User avatar
tikibar
 
Posts: 514
Joined: Mon Mar 05, 2012 6:05 am
Location: Los Angeles
Callsign: CHT0009
OS: Ubuntu 14.04

Re: 747 in the cockpit

Postby Gijs » Thu Apr 03, 2014 7:42 pm

Hi,

the 744's 3D cockpit is a work in progress, but the AP switches are supposed to be working. Could you be a bit more precise on what doesn't work?

Cheers,
Gijs
Airports: EHAM, EHLE, KSFO
Aircraft: 747-400
User avatar
Gijs
Moderator
 
Posts: 9378
Joined: Tue Jul 03, 2007 2:55 pm
Location: Amsterdam/Delft, the Netherlands
Callsign: PH-GYS
Version: Git
OS: Windows 10

Re: 747 in the cockpit

Postby KL-666 » Tue Apr 08, 2014 8:29 pm

I tried this 747-8i of dogsaysmoo, and i must say it flies like a charm manually. Also there are a lot of improvements compared to the fgbr version, like now it is able to make turns on taxiways.

But the A/P is a big problem. Climbing to fl 400 works, but then the problems start. It will not level off. Hitting alt-hold has no effect. And after that it wants to fly upside down. This A/P cruise issue should really be addressed to make it one of the best planes of fg.

Kind regards, Vincent
KL-666
 
Posts: 784
Joined: Sat Jan 19, 2013 1:32 pm

Re: 747 in the cockpit

Postby azims » Tue Apr 08, 2014 8:54 pm

I agree with KL-666. It is much better than FBGR, but the autopilot is not very stable. Using the dialog menu and the cockpit buttons interchangeably, can create instability. I don't know which works better - the dialog box or the cockpit and wasn't able to isolate the problem or even reproduce. In any case, it is a nice piece of work and consider as WIP.
azims
 
Posts: 38
Joined: Mon Aug 12, 2013 7:56 pm
Callsign: AS
Version: 2017.2.1
OS: Windows 10

Re: 747 in the cockpit

Postby Jabberwocky » Wed Apr 09, 2014 2:26 am

I had the 747 from the FlightGear side and another one from I forgot where. So, maybe it's a mess up on my side. What I really also would wish is mousewheel on the course and alti knobs, but that's probably just luxury? Like in the 777?

J.
Jabberwocky
Retired
 
Posts: 1319
Joined: Sat Mar 22, 2014 7:36 pm
Callsign: JWOCKY
Version: 3.0.0
OS: Ubuntu 14.04

Re: 747 in the cockpit

Postby Jabberwocky » Wed Apr 09, 2014 2:56 am

Okay, downloaded it, same model. I took it for a spin. The AP buttons are all there and clickable but THR throws the whole bird in some swing motion and doesn't correspond with anything in the AP-menu. FLCH reacts sometimes on a click, sometimes not. Or maybe it reacts, but shows no light on the button, I'm not sure because when I pressed at the same time HDG, the whole bird went spontanously down. Deep down. So, either I do something seriously wrong or there is a bug somewhere. Where can I set autothrottle on this 8i? I assumed, it would be THR ...

J.
Jabberwocky
Retired
 
Posts: 1319
Joined: Sat Mar 22, 2014 7:36 pm
Callsign: JWOCKY
Version: 3.0.0
OS: Ubuntu 14.04

Re: 747 in the cockpit

Postby tikibar » Wed Apr 09, 2014 8:48 am

@KL-666 and azims: Thanks for trying it out and providing feedback. I want to try to fix the problem with the AP, but I don't know how to reproduce it. It works fine for me, of course. Could you tell me what settings you're making and when you're making them? Also the speed. At FL400, you're right around coffin corner. The AP cuts out if you drop below stall speed, in which case none of the buttons will do anything.

This is how I typically do a climb with the AP:
-Before takeoff, I set the target altitude, dependent on weight - we'll call it 36000 for this example.
-After takeoff, somewhere above 200 ft, I click one of the CMD buttons to turn on the AP and I click the SPD button to turn on the autothrottle.
-Then I click on V/S mode, which initializes to the current vertical speed. Then I adjust the vert speed to 2000 fpm, 2500 if flying light.
-Anytime before reaching FL360, I click FLCH, which arms the ALT hold. [edit]: not anymore. V/S arms FLCH automatically now.
-As I climb, I dial back the vertical speed to keep the IAS up. As I'm approaching FL360, I'll have V/S down to 500 fpm.
-At 35950, it automatically switches to ALT hold and holds at FL360.

There's a brief guide to the 747-8 AP included in the download package (about_autopilot.pdf).

As for the AP dialog and the panel, the buttons should be doing the same things - they call the same nasal functions. I almost never use the dialog, though, so I would say it is not as extensively tested as the panel.

@jabberwocky: on the -8, THR does nothing. SPD, right below it, activates and deactivates the AT.
Last edited by tikibar on Fri Apr 11, 2014 10:15 am, edited 1 time in total.
Boeing 747-8 (rename folder to 747-8i)
Boeing 757-200/300 (rename folder to 757-200)
Boeing 767-300/ER (rename folder to 767-300)
McDonnell Douglas MD-11 (rename folder to MD-11)
User avatar
tikibar
 
Posts: 514
Joined: Mon Mar 05, 2012 6:05 am
Location: Los Angeles
Callsign: CHT0009
OS: Ubuntu 14.04

Re: 747 in the cockpit

Postby Jabberwocky » Wed Apr 09, 2014 2:25 pm

Okay, I see at least one thing, I did wrong (I used THR instead of SPD).
Here is what happened with FLCH: I went up, flap 20 and all till about 4000 ft manually till gear and flaps were in, slowly climbing. Then I switched to A/P (preset to 10000ft). After changing that to 25000, FLCH doesn't light up and the hold stabilzes still at 10000ft. I had to use the A/P menu instead of the controls to make the plane climb to 25000.
Another test was, to bring her up to 40000ft. When reaching a waypoint, while the A/P changed course, the plane went down in a kind of dive bomb to 18000ft. Alt was still set for 40000.
However, I have small old hardware, so I wouldn't exclude the possibility, something goes wrong on my end and it is no bug.
A stupid question, but what would the THR-button intended to do or is that just a remnant from the -400?
Jabberwocky
Retired
 
Posts: 1319
Joined: Sat Mar 22, 2014 7:36 pm
Callsign: JWOCKY
Version: 3.0.0
OS: Ubuntu 14.04

Re: 747 in the cockpit

Postby azims » Wed Apr 09, 2014 2:35 pm

Jabberwocky articulated well the issue in his last 2 posts.

The AP dialog from 747-400 by Gijs is very stable and has always worked for me. Never had an issue. Would it be possible to use the same AP? The difference between the 747-400 and the 747-8i is the size, range and probably the engines (of course my knowledge is very limited so excuse me if I am overlooking something important). So why not keep the AP same as we know it works!

@tikibar - good job on the 8i. Nice piece of work.
azims
 
Posts: 38
Joined: Mon Aug 12, 2013 7:56 pm
Callsign: AS
Version: 2017.2.1
OS: Windows 10

Re: 747 in the cockpit

Postby tikibar » Wed Apr 09, 2014 3:35 pm

On the panel, FLCH doesn't engage automatically unless you're using the VNAV* (which I'd only recommend using for making step climbs during cruise). Otherwise, you have to click the FLCH button after you set a new target altitude with the ALT knob. The new altitude isn't entered into the autoflight system until you do this, unless the FLCH light is already on. [edit]: V/S mode now arms FLCH automatically too.

What vertical mode were you using? The only one that would have leveled you off at 10000 would be VNAV if it was activated below 10000 feet, but that should have kicked on the FLCH light (I think). Only other explanation I can think of is you dropped to stall speed and the AP cut out and you just happened to level off naturally at exactly 10000 feet - sounds pretty likely, right? The drop from 40000 to 18000 also sounds like a VNAV thing.

Basically, there are 3 ways to handle vertical with the AP.
(1) You can use the ALT knob and FLCH (with or V/S if you like) to climb (or descend) to and stay at a target altitude;
(2) you can just use V/S and manually disarm FLCH by clicking the button after engaging V/S, and then hit the ALT HOLD button when you get to the altitude you want; or
(3) you can use the VNAV which is the same as (1) except the route manager changes the altitude setting and pushes the FLCH button for you.
The FL400 to 18000 trip at a waypoint sounds like the route manager changed your target altitude, but it shouldn't have gone more than about 1500-2000 fpm.

I don't know much about the THR button. I think it's related to the FADEC and/or using pitch to hold speed, neither of which are modeled. That's why the button doesn't do anything.


* There are weather-related causes for ALT hold mode to automatically jump to FLCH temporarily when the METAR or weather tile changes, but that's not too relevant here. [edit]: FLCH now automatically arms when V/S mode is selected.
Last edited by tikibar on Fri Apr 11, 2014 10:19 am, edited 1 time in total.
Boeing 747-8 (rename folder to 747-8i)
Boeing 757-200/300 (rename folder to 757-200)
Boeing 767-300/ER (rename folder to 767-300)
McDonnell Douglas MD-11 (rename folder to MD-11)
User avatar
tikibar
 
Posts: 514
Joined: Mon Mar 05, 2012 6:05 am
Location: Los Angeles
Callsign: CHT0009
OS: Ubuntu 14.04

Re: 747 in the cockpit

Postby ja sam niko » Wed Apr 09, 2014 3:43 pm

I hope I don't disturb.

I did a test flight with this aircraft last night. Just a short one,to check it out. And the result is this.

The autopilot don't have too much of a problem. To use it completely from the cockpit doesn't seem to work properly. But ,when using the autopilot dialog,it works perfectly. I was not climbing to FL400,actually just to FL300 but everything seems to work without problems,when using it that way.

A little bit off topic...
The cabin lights are always on and I can't find the way to turn them off. I mean,you don't need them in the middle of the day...right? :) BTW,the fuel burn seems to be a little bit too high...any ideas about that?

All in all,the 747-8 is amazing...so good job.

Cheers
The worst floods in the Balkans ever,follow these links to learn more how to help. Thank you.
http://www.google.org/crisisresponse/2014-balkans-floods

http://www.mvp.gov.ba/HTML/eng-help.pdf
ja sam niko
Retired
 
Posts: 210
Joined: Sun Feb 23, 2014 7:52 pm
Location: LQBK
Callsign: ex FGRS,now UAV001
Version: 2.8
OS: WinXP

Re: 747 in the cockpit

Postby tikibar » Wed Apr 09, 2014 5:59 pm

Thanks, guys, for the kind words. This has been a labor of love for me over the last couple of years since the bygone era of 2.4. :)

@azims - It's not so simple to just swap the APs because the -400 is a jsbsim model and the -8 is yasim. The AP tuning is very different for the 2 FDM types. I think the best way forward is to fix this one and/or provide some good documentation for it.

The problem I have with fixing it is I don't know where to start. Aside from the VNAV, the functions I use on it work flawlessly for me. Actually, on the rare occasion that I've used the VNAV, it has worked fine too. So I guess what I need is some very specific information from other pilots who have trouble with it so I can try to track down problems I haven't experienced myself. This would include: lateral and vertical mode settings, air speed, altitude, and climb, cruise or descent. I need to know what buttons you're pushing. Each button, knob and switch on the MCP is connected to a nasal function that does a number of things, many of which are interconnected. And some things aren't really intuitive, for example: changing the altitude setting while in ALT hold mode does not command a change in altitude; it just changes the altitude setting. FLCH commands the change in altitude. In short, tell me what you did, what you expected to happen, and what the AP did instead.

@ja sam niko - yeah.. the cabin lights. The windows and cabin lights are not the usual cutouts in the fuselage. They're more of an overlay of white squares with high emissivity. I just haven't found the interest in texturing to try to fix them. I'm more of a systems engineer than a painter. I did very little texture and 3d work on this. Most of that comes from the original FGBr model, much of which came from Gijs originaler 747-400.

Fuel burn is okay I think. It can make the full 8000 nm range on full tanks with enough reserves to keep it legal.
Boeing 747-8 (rename folder to 747-8i)
Boeing 757-200/300 (rename folder to 757-200)
Boeing 767-300/ER (rename folder to 767-300)
McDonnell Douglas MD-11 (rename folder to MD-11)
User avatar
tikibar
 
Posts: 514
Joined: Mon Mar 05, 2012 6:05 am
Location: Los Angeles
Callsign: CHT0009
OS: Ubuntu 14.04

Re: 747 in the cockpit

Postby KL-666 » Wed Apr 09, 2014 8:55 pm

Hello Tikibar,

You wrote:

This is how I typically do a climb with the AP:
-Before takeoff, I set the target altitude, dependent on weight - we'll call it 36000 for this example.
-After takeoff, somewhere above 200 ft, I click one of the CMD buttons to turn on the AP and I click the SPD button to turn on the autothrottle.
-Then I click on V/S mode, which initializes to the current vertical speed. Then I adjust the vert speed to 2000 fpm, 2500 if flying light.
-Anytime before reaching FL360, I click FLCH, which arms the ALT hold.
-As I climb, I dial back the vertical speed to keep the IAS up. As I'm approaching FL360, I'll have V/S down to 500 fpm.
-At 35950, it automatically switches to ALT hold and holds at FL360.


I tried this, especially the "Anytime before reaching FL360, I click FLCH, which arms the ALT hold", and it works.

Just some remarks:
- FLCH and VS are kind of complementary, so i did not expect to have to use them together.
- "Coffin corner" is kind of zero at fl 400, so you can not fly at fl 400. The above and below red bars in the speed strip touch each other. Seems not right for 747. Max alt of most planes is just above fl 400. I think there should be some more space between the red bars above and below in the speed strip when at fl 400.
- If anything goes goes wrong (At coffin corner) there is no stabalizing by autopilot possible anymore. It starts to roll until upside down. Even when descending to a wider coffin corner. Only full kill of A/P makes a recovery possible.

Kind regards, Vincent
KL-666
 
Posts: 784
Joined: Sat Jan 19, 2013 1:32 pm

Re: 747 in the cockpit

Postby KL-666 » Wed Apr 09, 2014 9:45 pm

Tested at lower alt now, fl 340 with wider coffin corner. Still at some moment it will only hang left in A/P, shaking a bit between level and left. I think it is induced by real weather (as opposite to basic weather). This real weather has some rather extreme wind changes aloft, with which this 747 can not cope and gets into a "i want to turn left" frenzie.

Kind regards, Vincent
KL-666
 
Posts: 784
Joined: Sat Jan 19, 2013 1:32 pm

Next

Return to Cockpit development

Who is online

Users browsing this forum: No registered users and 1 guest