Board index FlightGear Support Flying Helicopter

helicopter failure hellp

Helicopter flying is completely different from flying a fixed-wing aircraft and thus requires different skills.

helicopter failure hellp

Postby Gederson » Thu Apr 02, 2020 3:31 am

Friends, I can't get the helicopter off the ground, I increase the power, and when it comes up, it tilts and falls.
I'm using page up to increase power, enter and zero to control the rudder, when he wants to go up, I give the mouse a little pull back, where am I missing? :cry: :cry: :cry: :cry: :cry:
Gederson
 
Posts: 16
Joined: Tue Mar 24, 2020 9:17 am

Re: helicopter failure hellp

Postby Thorsten » Thu Apr 02, 2020 6:24 am

Do not center the controls - you need to have the controls set to compensate all rotor moments at the liftoff point (you can try by creefully trying to lift a single skid) - the wiki has a nice introduction on how to fly a helicopter.

Also, you do not actually vary power to lift off in a helicopter - you gradually change the AoA of the rotor blades ('collective').

With a helicopter, it's really important that you understand the theory of what you're trying to do first (and then give it lots of practice - you will crash the first 20 times...) - it's not an easy thing to learn.
Thorsten
 
Posts: 11578
Joined: Mon Nov 02, 2009 8:33 am

Re: helicopter failure hellp

Postby Gederson » Thu Apr 02, 2020 6:51 am

I believe that the collective is the mouse up and down, sides, when it turns into a cross, but it cancels the rudder, so the helicopter loses control on the spot
Gederson
 
Posts: 16
Joined: Tue Mar 24, 2020 9:17 am

Re: helicopter failure hellp

Postby FlugHund » Thu Apr 02, 2020 9:04 am

Wrong guess, that's called the 'cyclic' control.
http://wiki.flightgear.org/Howto:Fly_a_helicopter
User avatar
FlugHund
 
Posts: 540
Joined: Thu Mar 01, 2007 3:27 pm
Callsign: D-HUND
IRC name: D-HUND / debdog
Version: next
OS: Devuan

Re: helicopter failure hellp

Postby Johan G » Thu Apr 02, 2020 10:22 am

@Gederson: Helicopters are probably the most counter-intuitive vehicle humans have ever created.*

I very highly recommend you watch this YouTube playlist:
Smarter Every Day DEEP DIVE #1 - Helicopters Physics!
___
* Yes, even more counter-intuitive than orbital mechanics. :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)
Johan G
Moderator
 
Posts: 5691
Joined: Fri Aug 06, 2010 5:33 pm
Location: Sweden
Callsign: SE-JG
IRC name: Johan_G
Version: 3.0.0
OS: Windows 7, 32 bit

Re: helicopter failure hellp

Postby Thorsten » Thu Apr 02, 2020 10:44 am

when it turns into a cross, but it cancels the rudder, so the helicopter loses control on the spot


If the cyclic actually interferes with the pedals, make sure auto-coordination is off (this literally kills you in helicopters...). You need to be able to control pedals separately (and reasonably fast).
Thorsten
 
Posts: 11578
Joined: Mon Nov 02, 2009 8:33 am

Re: helicopter failure hellp

Postby StuartC » Thu Apr 02, 2020 12:28 pm

Lots of choppers have a tendency to roll one way or the other ( depends ob blade rotation direction , torque and few other little things including how the engine is mounted.). A Few of the modern ones have systems in place that minimises the effects. ( S76 for one has a very neutral takeoff profile ).
Rudder/yaw input on the tail rotor just compensates for yaw, not Roll. Foll is a Cyclic input on the joystick. Although non inline tail rotors can induce a small pitch up or down in the nose attitude when applying pedal ( depends on blade rotation again if left pedal would induce pitch up or down for example ). Inline tail rotors lessen the effect greatly. This is where the tail rotor is in a raised position near inline with the main rotor, like a Huey.

out of interest which chopper have you been trying ?
StuartC
 
Posts: 2813
Joined: Fri Jun 18, 2010 8:18 pm
Location: Arse end of the Universe
Callsign: WF01
Version: 2019.1
OS: W10 64 bit

Re: helicopter failure hellp

Postby Hooray » Thu Apr 02, 2020 1:43 pm

the nature of the generic autopilot/pid controller system makes it rather straightforward to use that to control one or two axes while you're learning to control the other axis
Please don't send support requests by PM, instead post your questions on the forum so that all users can contribute and benefit
Thanks & all the best,
Hooray
Help write next month's newsletter !
pui2canvas | MapStructure | Canvas Development | Programming resources
Hooray
 
Posts: 11738
Joined: Tue Mar 25, 2008 8:40 am

Re: helicopter failure hellp

Postby Thorsten » Thu Apr 02, 2020 5:01 pm

the nature of the generic autopilot/pid controller system makes it rather straightforward to use that to control one or two axes while you're learning to control the other axis


Did you actually try that? I believe that might be an excellent way of getting yourself killed... A helicopter AP is definitely not a straightforward out of the box problem, especially if it's supposed to handle the hover phase (to my knowledge, Amelia still is the only FG system that can take off a helicopter automatically... :P )
Thorsten
 
Posts: 11578
Joined: Mon Nov 02, 2009 8:33 am

Re: helicopter failure hellp

Postby Hooray » Thu Apr 02, 2020 6:01 pm

yes, I've repeatedly done that before - and it works well enough, even without customizing the standard PID controller.
I don't see any reason why this should no longer work - the mode won't work as you expect, but you can definitely stabilize one axis while manipulating the other one/s
I also once came up with a customized PID controller that would accept properties, too - to hook up different PIDs dynamically.

But then someone in the FG community came up with a dedicated PID based autopilot that worked for most helicopters, so I considered that obsolete - until the maintainer of the corresponding helicopter decided the feature was unrealistic, and simply reverted the commits/contribution.

And like you say, hovering is a completely different beast (the generic AP I mentioned did support hovering).

Personally, I would probably "cheat" by using the groundspeed/position properties and hook those up to the PID

Again, it's possible to do this "as is", but the "modes" won't do what you expect them to do (as in heading or altitude hold), it's more akin to "fixing" one axis while manipulating the other ones.

I don't remember the details/name of the helicopter that had said generic rotary AP, but the commit logs should still contain all the nitty gritty details.

Like you, I would probably be inclined to implement something like that via Nasal code - but all that presumably happened at a time when property rules were not yet around, so there may be better ways today.
Please don't send support requests by PM, instead post your questions on the forum so that all users can contribute and benefit
Thanks & all the best,
Hooray
Help write next month's newsletter !
pui2canvas | MapStructure | Canvas Development | Programming resources
Hooray
 
Posts: 11738
Joined: Tue Mar 25, 2008 8:40 am

Re: helicopter failure hellp

Postby Gederson » Mon Apr 13, 2020 6:00 am

Thorsten wrote in Thu Apr 02, 2020 10:44 am:
when it turns into a cross, but it cancels the rudder, so the helicopter loses control on the spot


If the cyclic actually interferes with the pedals, make sure auto-coordination is off (this literally kills you in helicopters...). You need to be able to control pedals separately (and reasonably fast).




"make sure auto-coordination is off",

WHERE I DISABLE

:lol: :lol: :lol:
Gederson
 
Posts: 16
Joined: Tue Mar 24, 2020 9:17 am

Re: helicopter failure hellp

Postby Gederson » Mon Apr 13, 2020 6:11 am

StuartC wrote in Thu Apr 02, 2020 12:28 pm:Lots of choppers have a tendency to roll one way or the other ( depends ob blade rotation direction , torque and few other little things including how the engine is mounted.). A Few of the modern ones have systems in place that minimises the effects. ( S76 for one has a very neutral takeoff profile ).
Rudder/yaw input on the tail rotor just compensates for yaw, not Roll. Foll is a Cyclic input on the joystick. Although non inline tail rotors can induce a small pitch up or down in the nose attitude when applying pedal ( depends on blade rotation again if left pedal would induce pitch up or down for example ). Inline tail rotors lessen the effect greatly. This is where the tail rotor is in a raised position near inline with the main rotor, like a Huey.

out of interest which chopper have you been trying ?




Good night, the closest I was able to climb was with the ec130. I am in love with huey- iroquay-h1, however, it doesn't even go up ...
I saw that on the ec130 you have to increase the rotation by 100%, but on other helicopters this is not necessary.
Another thing, do you know how to disable automatic rudder coordination?
Gederson
 
Posts: 16
Joined: Tue Mar 24, 2020 9:17 am

Re: helicopter failure hellp

Postby FlugHund » Mon Apr 13, 2020 9:09 am

Gederson wrote in Mon Apr 13, 2020 6:11 am:Another thing, do you know how to disable automatic rudder coordination?

Add --disable-auto-coordination to the command line. You can do that in the Launcher's Settings dialogue, at the very bottom.
User avatar
FlugHund
 
Posts: 540
Joined: Thu Mar 01, 2007 3:27 pm
Callsign: D-HUND
IRC name: D-HUND / debdog
Version: next
OS: Devuan

Re: helicopter failure hellp

Postby Gederson » Mon Apr 13, 2020 9:33 am

FlugHund wrote in Mon Apr 13, 2020 9:09 am:
Gederson wrote in Mon Apr 13, 2020 6:11 am:Another thing, do you know how to disable automatic rudder coordination?

Add --disable-auto-coordination to the command line. You can do that in the Launcher's Settings dialogue, at the very bottom.




great, I'll try then the way you said, just write as below:
- Launcher settings, then ... write
--disable-auto-Coordination

Anything else?
Gederson
 
Posts: 16
Joined: Tue Mar 24, 2020 9:17 am

Re: helicopter failure hellp

Postby FlugHund » Mon Apr 13, 2020 9:38 am

Gederson wrote in Mon Apr 13, 2020 9:33 am:[...]
--disable-auto-Coordination

Anything else?


Yes, it is case sensitive!
User avatar
FlugHund
 
Posts: 540
Joined: Thu Mar 01, 2007 3:27 pm
Callsign: D-HUND
IRC name: D-HUND / debdog
Version: next
OS: Devuan

Next

Return to Helicopter

Who is online

Users browsing this forum: No registered users and 1 guest