Jump to content

Advanced Flight Model with Uncle Gandalf

Recommended Posts

For those of you interested in learning how to fly in the advanced flight model, I've written some notes below and made a short demonstration video to show you some of the stuff I'm talking about. It's a steep learning curve but it's also incredibly rewarding. Arma 3's advanced flight model offers probably the best simulation I've found so far of actual rotor-wing flight, and while it isn't quite the real thing, it gets stuff right that other simulators don't.


For those of you that are completely new to the advanced flight model, the key difference is that the main rotor now generates torque. The torque of the main rotor causes the helicopter to spin in the same direction, and if you want to fly in a straight line, you have to cancel out the induced rotation (hence why the tail rotor is called the "anti-torque" rotor).


To avoid confusion below, I will refer to "throttle" and "power" as "collective". But collective and throttle aren't actually the same thing -

  • Collective is a flight control that adjusts the angle of the main rotor to generate lift, also increasing aerodynamic drag and therefore reducing rotor speed, or RPM.
  • Throttle is the main engine power and affects rotor RPM.


In old helicopters, you'd have to carefully adjust the throttle to match the collective's setting so that the rotor RPM didn't reach dangerously low or high levels. However, in modern helicopters (and in Arma helicopters), you don't control the throttle. You control the collective and a governor automatically adjusts the throttle to maintain an appropriate rotor RPM.


Before venturing into the advanced flight model any deeper, I would suggest you get yourself a set of flight controls - some sort of analogue throttle control, a joystick and generic rudder pedals. It is possible to fly in the AFM with mouse & keyboard but the learning curve is much steeper, your movements will be sloppy and you'll find that building muscle memory takes weeks and months rather than days.


Your first challenges are going to be maintaining a hover, navigating taxiways and flying straight and level. All of these rely on building muscle memory with your feet, allowing you to correct the helicopter's axial rotation with an appropriate level of sensitivity in the anti-torque rotor. Note that, if you increase collective, the torque generated by the main rotor increases - so you have to apply more corrective pedal at a high collective than you would at a lower collective. In the video at the end of this post, look at how much the helicopter banks when flying straight and level, and compare that to how much the helicopter banks when taking off with full collective. The banking in this case is the amount of correction needed to counter the main rotor's torque.


Don't worry about landing until you've mastered the more basic flight controls. If you learn the basics first then landing will become much easier.


When conducting a landing in the AFM, it's much the same as in the standard flight model - drop collective, nose up, bleed off speed, gently touch the ground. But there's some further complications...

  • Ground Effect. This occurs when you're very low to the ground - the main rotor creates a bouncy cushion of air between the ground and the main rotor, as the air being thrust into the ground doesn't have anywhere to go. Ground Effect is actually your friend most of the time, it allows you to take off with less throttle and slightly cushions your landing at the critical point just before you touch down. But if you don't remember to take it into account, it'll be your worst enemy.
  • Vortex Ring State (VRS). VRS occurs when you descend in a straight line without any lateral speed. The rotors descend into their own turbulent air and struggle to generate lift. The worst part of VRS is that the instinctive reaction is to increase collective, but this actually makes the situation worse (exact results depending on power-weight ratio). A helicopter in VRS will experience pronounced wobbling (like a magnitude 6 earthquake) and will move very unpredictably. To get out of VRS, you need to drop collective and nose forward to get out of the turbulent air. You'd better hope you're more than 30ft above the ground if this happens!


And here's the video - some demonstrations and some useful knowledge to have.


Video Bookmarks:

  • Rotor RPM - 0:26
  • Vortex Ring State -  2:12. VRS looks different in vanilla Arma, ACE must be doing something here.
  • Autorotation - 4:12
  • Ground Effect - 5:31
  • Traffic Pattern - 6:49
  • Free Flight - 12:15




Link to comment
Share on other sites

Great idea, personally I've flown with advanced flight model since it came out and never felt like going back. I'd love to see more people try it out!


Sent from my SM-G935F using a phone app that is really irritating because it constantly advertises itself.



Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Forum Statistics

    Total Topics
    Total Posts
  • Create New...