Autorotation’s!

[KosPilot 10]

Something else I noticed is the effects of forward or rearward speed vs. cyclic position is seemingly opposite (left><right) to what it should be, the retreating rotor blades are on the left, the advancing rotor blades are on the right when flying forwards, when transitioning from trimmed stick centre hover forwards you need to move the stick with bias for left of centre for level flight in-game, when flying backwards you need bias right of centre for level flight in-game which both go directly opposite left/right of what they should, i.e. if you are trimmed centre stick in a hover and you fly forwards slowly building speed with the advancing blades on the right then you would expect that side to start generating more lift than the retreating left side thus by implication require less blade pitch while the retreating side requires more blade pitch to account for the blades relative air-flow speed differences, if you are having to go into left stick bias as forward speed rises that means you are increasing the pitch on the advancing right side and decreasing it on the retreating left side. :confused:

b101_uk, I absolutely love your thread and whish that BI gets it right!

What you are describing is onflow roll. What is experienced in the sim is correct.

Inflow roll is created when the rotordisc is moving into relative wind. The fore sector of the rotordisc will move into "clean" air, but as the rotordisc move through, the air will be accelerated downwards through the rotordisc at an increased velocity as approaching and passing the aft sector.

This causes less lift to be produced by the aft section compared to the fore section. Due to gyroscopic precession, the rotordisc will now tilt towards the advancing blade and cause a roll to the right. -Correct with left cyclic (if accelerating forwards). The inflow roll is most noticeable when going through ETL.

As you speed up, the advancing blade will start to create more lift than the retreating blade. Again, because of gyroscopic precession, that will cause the rotordisc to tilt up towards the direction of incoming relative wind. If accelerating forwards, this will cause the nose of helicopter to pitch up. -Correct with forward cyclic.

From this description you'll see that an attitude correction by cyclic input is initiated by changing blade angles at ~90 degrees preceding the resulting rotor tilt.

By now, I hope you are no more confused that what I am ;)

[zentaos 10]

ahh...but what about dissymmetry of lift. it will roll ..., but don't forget gyroscopic precession, and this effect...

I love all of these discussions.

Some of us may have a good understanding of some of the physics at work in helicopter flight, but it is very difficult to understand them all working together and understand the effects that they will have and the control inputs required to counteract the effects.

I have actually flown in an R22, I have less than 3 hours, and have ridden in the back seat of an Astar 350. So i have more experience than some. I still, however, no enough to understand that I really know very little.

I can't wait to hear the impressions of all the real world licensed pilots on the flight model of the beta and full game, because they are the only ones who have a true understanding of all the forces working together.

[ocramweb 0]

@kospilot onflow what is experienced in the game regarding annoying roll is nothing like translational lift then inflow roll (transverse flow), it happens at many speed and last with increased speed, which should not be the case.

@zentaos http://forums.bistudio.com/showthread.php?t=122626

Edited October 7, 2011 by ocramweb

[Myrddin 10]

It has been a while since I last flew helicopters, been pilot int he german army aviation forces up to like 20 years ago :D Always been looking for a semi realistic helicopter sim which would let me fly around a bit if I wanted to. But back to the core of this post.

As seen in other posts the hardest part is hovering since you basically have to adjust all controls to be in balance while sliding down from your cushion of air.

From the video it looks that you come in quite fast and you forget to bring up your nose just before you hit the ground. While you are descending the air will keep your rotor going, but it all has to be within limits ... you can't be too fast and you rotor can't be too fast either. Think if I remember right our Alouette II had a speed of 50-60 knots for autorotation ... you have to take speed and energy out while descending if you come too fast. Jsut befor you touch ground you pull the pitch and use the energy stored in your rotor to create a cushion of air which you need to use to reduce the speed more and more before actually touching the ground. The alouette usually slided around 30-60m on wet grass and you needed to be ready to pull back in case the nose would go down.

Hope that helps