Board index FlightGear Support Flying

Why does my airplane runs off the track when taking off?

Controlling your aircraft, using the autopilot etc.

Why does my airplane runs off the track when taking off?

Postby Zequinha » Wed Mar 22, 2017 2:47 pm

Hi folks,

I am puzzled as to why every single aiplane I choose (Piper J-3 Cub, Carreidas 160, etc...) instead of following a straight line while taking off, it starts to exhibit weird motion, turning left or right and falling off the track before I get the chance of lifting off the ground. I know it is not a problem of the joystick because this weird behaviour also happens when i use only the keyboard.

FlighGear 2017.1.1, even though this problem also happened to me with previous versions.

Any ideas why this is happening?
Zequinha
 
Posts: 204
Joined: Sun Mar 13, 2016 5:26 pm
OS: GNU

Re: Why does my airplane runs off the track when taking off?

Postby FlugHund » Wed Mar 22, 2017 3:07 pm

User avatar
FlugHund
 
Posts: 568
Joined: Thu Mar 01, 2007 4:27 pm
Location: Inside ground effect
Callsign: D-HUND
IRC name: D-HUND / debdog
Version: next
OS: Devuan

Re: Why does my airplane runs off the track when taking off?

Postby Zequinha » Wed Mar 22, 2017 3:36 pm

Awesome! Thanks for the info!

Now, in the case of jet aircraft, e.g. carreidas, could the crosswinds explain the deviation from the track? If so, how do I counteract this, as turning right/left won't actually do anything!
Zequinha
 
Posts: 204
Joined: Sun Mar 13, 2016 5:26 pm
OS: GNU

Re: Why does my airplane runs off the track when taking off?

Postby Johan G » Wed Mar 22, 2017 4:46 pm

It depends a bit on what controls you are using, but in general crosswinds can be easier to handle if you have separate a separate rudder axis (either using a twist joystick or rudder pedals), but with "some" training people have been able to use other means as well.

I have collected some good video lessons on real life crosswind technique in these two forum posts in the topic Interesting videos:


Note that while these techniques are demonstrated with GA* aircraft, they pretty much apply to all sizes of aircraft.

* GA = General Aviation, loosely meaning smaller propeller aircraft owned by flight clubs/schools or individuals.

Oh, its my 5071th post, like in HP/Agilent Technologies/Symmetricom/Microsemi 5071A Primary Frequency Standard, the most common of the atomic clocks contributing to the TAI atomic timescale. ;)
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Some YouTube videos
Johan G
Moderator
 
Posts: 6629
Joined: Fri Aug 06, 2010 6:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 2020.3.4
OS: Windows 10, 64 bit

Re: Why does my airplane runs off the track when taking off?

Postby Zequinha » Wed Mar 22, 2017 5:38 pm

Thanks once again for all the info.

I will try to set up a separate control for the rudder!
Zequinha
 
Posts: 204
Joined: Sun Mar 13, 2016 5:26 pm
OS: GNU

Re: Why does my airplane runs off the track when taking off?

Postby Zequinha » Mon Mar 27, 2017 1:52 pm

Indeed controling the rudder makes a big difference! :)
Zequinha
 
Posts: 204
Joined: Sun Mar 13, 2016 5:26 pm
OS: GNU

Re: Why does my airplane runs off the track when taking off?

Postby Clive2670 » Mon Mar 27, 2017 6:17 pm

A good joystick to maybe consider buying is the Thrustmaster HOTAS X see this link for info: http://www.thrustmaster.com/products/tflight-hotas-x The joystick has a twist axis for controlling the rudder and numerous programmable buttons. The twist function makes a very useful function for controlling "your" plane during crosswind landings and take-offs. Shop around though (Ebay, Amazon, ETC) as prices vary a lot! In my view this is a really versatile joystick that is fully programmable to cover virtually all the main things in the cockpit right from the cessna through to fighter jets and upto the 747! I use it daily in the 777-200LR, A lot easier than the keyboard when you have to be doing several actions at the same time during take-off or landing. Hope this is of help to you?
Thanks Clive aka: G-BLS01
Can be seen flying the Boeing 777-200LR
Toshiba laptop,
Intel i5 4210U,
16Gb RAM,
AMD R7-M260 graphics 2Gb RAM
Clive2670
 
Posts: 589
Joined: Mon Feb 08, 2016 8:11 pm
Location: Anywhere in the World at some point on Flightgear!
Callsign: G-BLS01
Version: 2018.3.1
OS: Windows 10 64bit

Re: Why does my airplane runs off the track when taking off?

Postby Zequinha » Wed Mar 29, 2017 10:19 pm

Thanks Clive2670! I also have a thrustmaster joystick but a more basic one: http://www.thrustmaster.com/products/usb-joystick

It's not ideal to control the rudder, I think. But I will try and see if I can program any of the top buttons to move the rudder!
Zequinha
 
Posts: 204
Joined: Sun Mar 13, 2016 5:26 pm
OS: GNU

Re: Why does my airplane runs off the track when taking off?

Postby Johan G » Thu Mar 30, 2017 7:11 pm

There are some rudder keys on the keyboard, though not all that intuitive to some. IIRC the keys corresponding to the control stick, rudder pedals and toe brakes interprets a quicker press as a smaller deflection change and a longer press as a larger deflection change. In any case you could have a look in $FG_ROOT/keyboard.xml for inspiration, where $FG_ROOT is the data directory in your FlightGear installation. There is a lot of Nasal code embedded in and also included into that configuration file. See also $FG_ROOT/Nasal/controls.nas to see some of the included Nasal functions.

tl;dr: Control input can be extremely flexible in FlightGear. :wink:
Low-level flying — It's all fun and games till someone looses an engine. (Paraphrased from a YouTube video)
Improving the Dassault Mirage F1 (Wiki, Forum, GitLab. Work in slow progress)
Some YouTube videos
Johan G
Moderator
 
Posts: 6629
Joined: Fri Aug 06, 2010 6:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 2020.3.4
OS: Windows 10, 64 bit

Re: Why does my airplane runs off the track when taking off?

Postby Zequinha » Thu Aug 03, 2017 9:27 am

Thanks guys,

But I realised I don't need this degree of realism and I want to turn off wind/crosswind effects or propeller torque for the propeller airplanes. I want to be able to take off aligned with the track out-of-the-box. How can I turn these effects off?
Zequinha
 
Posts: 204
Joined: Sun Mar 13, 2016 5:26 pm
OS: GNU

Re: Why does my airplane runs off the track when taking off?

Postby legoboyvdlp » Thu Aug 03, 2017 11:08 am

We don't really have an option to do that, as it is assumed that the user is willing to fly with this degree of realism. It is built-in to the simulator, as far as I know.
Is there a specific problem that causes you to be unable to use the rudder?
Many thanks,
Jonathan
User avatar
legoboyvdlp
 
Posts: 7981
Joined: Sat Jul 26, 2014 2:28 am
Location: Northern Ireland
Callsign: G-LEGO
Version: next
OS: Windows 10 HP

Re: Why does my airplane runs off the track when taking off?

Postby Zequinha » Thu Aug 03, 2017 12:11 pm

oh, no specific problem at all. It is just a matter of personal preference. I use FG as a game rather than a realistic simulator so for me, it would be great if I could adjust the realism settings of the simulation, from a gamers perspective.
Zequinha
 
Posts: 204
Joined: Sun Mar 13, 2016 5:26 pm
OS: GNU

Re: Why does my airplane runs off the track when taking off?

Postby wkitty42 » Thu Aug 03, 2017 3:05 pm

then you might want to look at a flying game instead of a simulator like flightgear...

remember, you can play games in a simulator but a simulator is not a game ;)
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
User avatar
wkitty42
 
Posts: 9146
Joined: Fri Feb 20, 2015 4:46 pm
Location: central NC, USA
Callsign: wk42
Version: git next
OS: Kubuntu 20.04

Re: Why does my airplane runs off the track when taking off?

Postby Zequinha » Mon Aug 07, 2017 10:43 am

wkitty42 wrote in Thu Aug 03, 2017 3:05 pm:then you might want to look at a flying game instead of a simulator like flightgear...

remember, you can play games in a simulator but a simulator is not a game ;)


Simulators in general should allow for different degrees of complexity and realism so the researcher can debbug and analyze the results of the simulation.

Having said this, I personally think it would be a valuable option. At least to compare the trajectory of the plane with crosswinds to that obtained in their absence, thus evaluating their effect.
Zequinha
 
Posts: 204
Joined: Sun Mar 13, 2016 5:26 pm
OS: GNU

Re: Why does my airplane runs off the track when taking off?

Postby Thorsten » Mon Aug 07, 2017 12:09 pm

Having said this, I personally think it would be a valuable option.


Then I suggest you get coding, because personally I think my time is wasted dumbing down the simulation I've worked hard to make realistic, and I've heard similar statements from other core developers.
Thorsten
 
Posts: 12490
Joined: Mon Nov 02, 2009 9:33 am

Next

Return to Flying

Who is online

Users browsing this forum: No registered users and 3 guests