Am I stalling? - advice required

[lucasdigital]

Hi,

 

I'm frequently finding that when I initiate a rapid vertical decent (dropping the collective) I'm unable to recover. I don't seem to be able to generate any lift at all. It's certainly my ham-fisted flying, but I'd appreciate any advise on what I might be doing wrong.

 

The most recent example - which by some fluke didn't result in complete destruction, thanks to the steep slope (Escort Mission in the Deployment campaign).

 

http://uk.youtube.com/watch?v=MvoV2VTA1YA

 

Thanks

 

Mk

[Nate--IRL--]

It's called a Vortex Ring State. To get out of it, increase your forward velocity, Do not pull more collective until your speed is above ~50km/h

 

Nate

 

Edit: An explanation http://en.wikipedia.org/wiki/Vortex_ring#Vortex_ring_effect_in_helicopters

 

Edit 2:- To avoid this do not decend at more than 3m/s when your speed is low. (say <50km/h) I'm sure others will come along to give more accurate figures.

Edited January 11, 2009 by Nate--IRL--

[Yellonet]

It's called vortex ring, if you descend too quickly, you'll enter your get into the rotors own downward turbulence... but someone else here can surely explain it better than me.

I get into them often too, but if you just move the cyclic a bit forward you can usually fly out the the vortex ring. If you need to descend quickly it's better to spiral down as if you're following a spring or coil downward.

Check out the training, they cover vortex rings there.

[lucasdigital]

Thanks for the quick response Nate. That's exactly what's happening. This never happened in Gunship 2000! ;-)

[lucasdigital]

It's called vortex ring, if you descend too quickly, you'll enter your get into the rotors own downward turbulence... but someone else here can surely explain it better than me.

I get into them often too, but if you just move the cyclic a bit forward you can usually fly out the the vortex ring. If you need to descend quickly it's better to spiral down as if you're following a spring or coil downward.

Check out the training, they cover vortex rings there.

 

Thanks Yellownet. I do recall mention of vortex ring state in the training, but not an actual explanation. I think I've recovered a couple of times with the application of cyclic. I'll definitely stop using the 'plummet' maneuver, it tends to end badly. :-)

 

Mk

--

Lucasdigital

[d0ppler]

When you're in a vortex ring state, lower collective and tilt nose forward to gain speed.

[Rhino4]

To clarify, I believe you can move in any direction to get out of VRS. Since you're in a helicopter, it makes no difference.

My 2 cents regarding what everybody else already said: The rotors are your wings. Because they spin through the air they generate lift. But if you're dropping fast enough, then it's the same as an airplane with no forward speed. You just drop like a rock because there's not enough airflow over the wings in the right direction to generate lift. You have to have enough speed in one direction for your helicopter's wings to generate lift again. Then you can increase collective and start getting altitude again.

[Frederf]

The best way to get out of VRS is never to get in it in the first place. Try to limit your decent rate when your airspeed is <60kmph or so. VRS is loss of lift due to descending through your own rotor wash which happens due to a combination of descending and low lateral airspeed.

 

Getting out of VRS requires not descending through your wash anymore. You could stop descending except you have a dramatic loss of lift in VRS so that's out. The practical way is to get the heck out of your wash by getting some airspeed. I know it sounds suicide but the first thing you must do in VRS is pitch down, power up, and get some airspeed up and sail into clear air.

[DTWD]

Sheffield UK aye?...a local boy.

 

If your out of combat operations and are just wanting to descend try descent mode, it automatically reduces your altitude by 2m/s while ever it is active (until your reach 4m, it's then supposed to stop but in reality you fall out of the sky if you keep it on) until you pancake.

[sobek]

To add to the above posts: Entering VRS is usually indicated by vibrations of the airframe, if you see this happening, you must emmediately start to recover. Note that this only happens if you enter the VRS slowly. Your violent descents however might send you directly into VRS without that indication. Also note that the manual is your friend ;)

[lucasdigital]

Thanks again guys. All your comments and explanations have been a big help. The rapid drop from a hover used to work on old inferior helicopter-sims. I'm sure I'll suffer the problem a lot less now It's clearly a form of blade stall.

 

It will be hard to go back to FSX helicopters when you get used to this level of fm fidelity.

 

Mk

[d0ppler]

It will be hard to go back to FSX helicopters when you get used to this level of fm fidelity.

 

Mk

I will NEVER go back to MSFS choppers unless they do some serious adjustments to their flight models :)