Board index FlightGear Development Aircraft Autopilot and route manager

Boeing 777 autopilot problem

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

Boeing 777 autopilot problem

Postby Mihajlo » Tue Jun 18, 2019 6:12 pm

I often encounter a problem with an autopilot where it won't turn on as it immediately disengages when I try to turn it on. It doesn't always happen and I don't think I'm doing anything differently, so I don't have a reliable way to reproduce it. This didn't happen before and I know there have been a lot of changes to 777 recently. I'm using the latest version from FGAddon. FG version is 2019.2.0 build 3394. Here is an error message I get in a nasal console: https://ibb.co/XzwN5g3
Mihajlo
 
Posts: 53
Joined: Tue Aug 28, 2018 5:47 pm

Re: Boeing 777 autopilot problem

Postby legoboyvdlp » Tue Jun 18, 2019 6:23 pm

You need to (like almost every airliner) have no flight control input when you engage autopilot. You can use the trim speed to maintain level flight and then engage autopilot when you have no input, or else release flight controls and immediately engage it.
User avatar
legoboyvdlp
 
Posts: 7584
Joined: Sat Jul 26, 2014 1:28 am
Location: Northern Ireland
Callsign: G-LEGO
Version: next
OS: Windows 10 HP

Re: Boeing 777 autopilot problem

Postby Mihajlo » Tue Jun 18, 2019 7:21 pm

Okay, thanks.
Mihajlo
 
Posts: 53
Joined: Tue Aug 28, 2018 5:47 pm

Re: Boeing 777 autopilot problem

Postby Octal450 » Tue Jun 18, 2019 9:01 pm

Also -- don't use V/S, use FLCH. It will give you proper climb rates/descent rates for your selected speed automatically using speed by pitch.

Kind Regards,
Josh
What I do: Flight Dynamics, Systems, Canvas Displays, Autoflight, FlyByWire, Cockpit Animations
Aircraft I currently develop: MD-11, A320-family, Secret

My GitHub|MD-11 and ITAF Development Discord|Airbus Development Discord
User avatar
Octal450
 
Posts: 4564
Joined: Tue Oct 06, 2015 12:51 pm
Callsign: WTF411
Version: next
OS: Windows 10 x64

Re: Boeing 777 autopilot problem

Postby Isaak » Tue Jun 18, 2019 9:18 pm

Hi there, thanks for the feedback! The listener errors you get were already present before, you just didn't see them because they weren't logged. Richard has changed something in the core code so they are shown. I 'll try to find where the listeners are called and replace them.
Want to support medical research with your pc? Start Folding at Home and join team FlightGear!
Isaak
 
Posts: 553
Joined: Sat Jun 04, 2011 2:52 pm
Location: Leuven, Belgium
Callsign: OO-ISA
Version: 2019.1.1
OS: Windows 10

Re: Boeing 777 autopilot problem

Postby Mihajlo » Thu Jun 20, 2019 7:57 am

You are welcome. Thanks for the tip. I'm glad you've decided to maintain and improve this aircraft. It was unmaintained for a long time without any improvements.
Mihajlo
 
Posts: 53
Joined: Tue Aug 28, 2018 5:47 pm

Re: Boeing 777 autopilot problem

Postby Octal450 » Thu Jun 20, 2019 2:25 pm

Enjoy :D

Josh
What I do: Flight Dynamics, Systems, Canvas Displays, Autoflight, FlyByWire, Cockpit Animations
Aircraft I currently develop: MD-11, A320-family, Secret

My GitHub|MD-11 and ITAF Development Discord|Airbus Development Discord
User avatar
Octal450
 
Posts: 4564
Joined: Tue Oct 06, 2015 12:51 pm
Callsign: WTF411
Version: next
OS: Windows 10 x64


Return to Autopilot and route manager

Who is online

Users browsing this forum: No registered users and 2 guests