Welcome back to Helicopter Lessons in 10 minutes or less. It's Jacob again. This is part two of the vortex ring state slash settling with power video. In the first video, we talked about what exactly is a vortex ring state.
What is settling with power? Kind of talked about the definitions. What does it look like on your rotor system in normal flight, early stages, and the vortex ring state?
In part two, we're going to be going over the three requirements for settling with power, the conditions that are conducive to it, as well as the recovery from settling with power. With that being said, what do you have to have to be in a vortex ring state? There's three requirements. One is going to have to be airspeeds less than ETL.
Now, we talked about in my other class about airspeeds less than ETL being airspeeds where you're being affected by wingtip vortices. Once you outrun effective translational lift, the aircraft is... operating in clean undisturbed air, it's outrun all of its vortices.
So obviously, if you can outrun vortices, you're not going to be in a vortex ring state. Number two is going to be a rate of descent greater than 300 feet per minute. And this is just going to be a condition that's conducive to this upwards flow of air that could potentially form these vortices.
Number three, it's going to be 20% to 100% of available power applied, usually with insufficient power to arrest the descent. But why 20% to 100%? Well, that's just saying that you have power applied. It's not a full-on autorotation. Obviously, in an autorotative state, it's only an upwards flow of air through the rotor system.
You're not going to have a difference of downflow and upflow through the rotor system. Alright, so that being said, these are the requirements that you have to have to get into a vortex ring state. If you break any one of these three, you can potentially, you can break your chances of getting into a vortex ring state.
But that being said, what kind of conditions are conducive to even entering into this vortex ring state? Well, one, Steep approaches. So a normal VMC approach angle is going to be about 8 to 10 degrees. An auto-rotative approach angle is going to be about 15 degrees. Steep approaches, normally you're looking at somewhere ballpark of 30 degrees.
But steep approaches, you're potentially coming in at air speeds less than ETL, greater than 300 feet per minute, 20 to 100% power applied. You're very, very... likely to get into a vortex ring state if you allow your airspeed and rate of descent to get within these ranges.
Another thing would be a downwind or a tailwind approach, and this is just because as you're getting to as you're beginning to reduce your airspeed, reduce your altitude and the approach, you're potentially dipping down less than 300 or less than ETL greater than 300 feet per minute. Very, very conducive to getting this vortex ring state and then allowing it to develop. Number three would be poor altitude control in an OG hover. So if you're an OG hover, you're potentially no airspeed. You do have power applied.
And this is just as simple as you're not doing a cross-check. You've allowed a rate of descent to build, potentially, say, 500 feet per minute rate of descent. And then now the rotor is in a vortex ring state. and you're operating in turbulent air and you're going to begin to settle with power. Four, hovering above your max hover ceiling.
Obviously this is hovering at a point where you really don't have a lot of power applied and you're generating a lot of vortices because you're already pulling a lot of power because you're at the top of that ceiling. Number five, descent from an OG hover. Just like what we were talking about before with steep approaches, poor altitude OGE. So descending from an OG hover you're potentially less than ETL.
You do have power applied, you're not in a pure auto-rotative state, and if you allow that rate of descent to get greater than 300 feet per minute you could potentially allow that vortex ring state to build. Lastly, formation approaches. Now formation approach, you're operating in somebody else's wingtip vortices.
So as you are On approach, you're getting into dirty, turbulent, disturbed air, potentially hitting some of their updrafts in a condition where you're already less than ETL with a greater than 300 feet per minute rate of descent. You could potentially get into a vortex ring state because the conditions for upflow have already been generated because you're flying into somebody else's upflow or their wingtip vortices. So this is where you're typically going to see it the most.
Obviously, anytime. you have any of these three, your potential for entering a vortex ring state is likely because you've met the required factors for it. Alright, so what do you do if you find yourself in a vortex ring state?
How do you recover? Well, one, there's the initial collective increase. Now didn't I just say, or you say earlier I said a collective increase could increase your rate of descent? Well in the early stages of this an initial collective increase increase could break this cycle before it gets into a full-blown vortex ring state.
So if you if you begin to get into any of these kind of conditions and there's suspected early stages of vortex ring state you can do an initial collective increase and you may be able to break out of it before you get into it. That being said if you increase the collective and it exacerbates your rate of descent then you've potentially already entered your vortex shrink state and now this collective increase is no longer an option. Now you're going to be looking at something like establishing some kind of directional flight. And this could be any kind of forward, left, right, back, anywhere to get some kind of directional flight.
Try to break through this ETL. If you're potentially in a high power environment and you're pulling a lot of power and you don't really have a lot To give, your best option is going to be something like a forward right cyclic with a right pedal. Because this right cyclic right pedal is going to reduce the amount of power required for the flight.
So you can potentially make these inputs and be able to pull just a little bit more collective to try to get out of this condition. Another option you have, altitude permitting, would be an auto rotation. Bottom out that collective, you're less than that 20% to 100% power applied, you've fallen through the vortex ring state, and then now you have a pure upwards flow of air. But don't just stop there.
With the auto rotation, obviously you want to accelerate through. If you enter the auto rotation and then immediately pull the collective back in, well now you've just re-entered your vortex ring state. So potentially enter your auto rotation, establish some kind of directional flight, and then begin to increase your collective and fly out of that vortex ring state. But most preferably, some of the experts out there say that if you enter a vortex ring state, establish that right forward cyclic with the right pedal and you'll exit it the most expeditious way.
So that was vortex ring state settling with power. Vortex ring state quite literally being just a state of vortices engulfing the rotor system settling with power is the result of continued flight in a vortex ring state, where the helicopter settles into its own downwash. It settles into that turbulent air.
But that wraps up the subject for today. I hope you guys enjoyed the video and hope it helped answer any questions you had. Make sure you hit like and subscribe below. And as always, stay flying.
Thanks for watching.