Its very easy...........don't land straight down, unless your like a foot off the ground. Always try to have some forward, rear left or right motion.
Unbelievably upset!
- Thread starter mountainpilot
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Its very easy...........don't land straight down, unless your like a foot off the ground. Always try to have some forward, rear left or right motion.
Unless the Inspire was descending at a very fast clip, like 4-5 m/s, there is no way that this could be VRS, which, as far as I know, is caused by a rotorcraft descending rapidly into its own prop wash, causing instability and uncontrollable flight. The OP stated that the Inspire was almost hovering, (quote: "The unit just dropped like a sack of potatoes from about 4-5 feet upon a return to home") and therefore could not have been descending rapidly enough to get into Vortex Ring State. Assuming it was almost hovering before dropping to the ground, the airflow at the props would have been clean, as 4-5 feet is well above ground effect. Look at all the videos of the Inspire hovering like a rock, indoors and outdoors, at eye level. There is something else going on here, but it's not VRS.
And Fastfjr, that is bad advice to recommend that one should have sideways motion when landing. Try that with your Phantom, if you have one, and see how well that turns out.
And Fastfjr, that is bad advice to recommend that one should have sideways motion when landing. Try that with your Phantom, if you have one, and see how well that turns out.
I agree with you quadpilot..I hope mountainpilot let's us know what the outcome is..I have a feeling it's going to work out for him...
Vortex Ring State, or more commonly called settling with power, is part of aerodynamics, and has nothing to do with ground effect. It occurs when the aircraft descends into its own disturbed air. It requires 3 things, the aircraft descending, the aircraft being below ETL (Effective Translational Lift which is aprx 20 KIAS in a bell 206, no clue what it is in regards to a medium multicopter), and there must be power applied (lift). Settling with power can occur at any altitude where these three conditions are met and the descent rate is fast enough. I believe that having such small "rotors" settling with power would be easier to get into, but ETL would be at a slower speed. Effectively the inner diameter of the rotor is no longer pushing air down and providing lift, but air is going up through the rotor system and causing loss of lift and more turbulent air causing the aircraft to descend further into the disturbed air. Applying more power once settling with power occurs will increase the severity of settling with power. Because settling with power is most likely to occur on approach, when close to the ground, it is a great risk to aviators and very dangerous if the proper recovery is not initiated by the pilot.
Prevention: Descend with forward movement to keep aircraft above ETL or descend at a slow rate as to not induce vortex ring state.
Recovery: Lower power, push forward on the cyclic to initiate forward movement, when positive rate is achieved (in helicopter positive increase in indicated airspeed) bring in power and climb to appropriate safe altitude.
Environmental factors that contribute: Hot, humid, high aircraft weight, high altitude.
Settling with power is problematic because the recovery is counter-intuitive, when a pilot is faced with an accelerated descent rate close to the ground the natural reaction would be to increase power which would result in a greater rate of descent, while the solution is to lower power and increase forward airspeed, taking the aircraft towards the ground before recovery can be made.
Could the crash have occurred from settling with power, I believe so... though I couldn't say what happened in this instance because I have not studied the effects of vortex ring state in UASs (though that could be really fun -- 4 rotors to interfere with one another... could get some craziness), and I wasn't there. Settling with power is, in a helicopter, is always accompanied by sever shuddering of the air-frame, and a rapid descent made worse by application of power.
Prevention: Descend with forward movement to keep aircraft above ETL or descend at a slow rate as to not induce vortex ring state.
Recovery: Lower power, push forward on the cyclic to initiate forward movement, when positive rate is achieved (in helicopter positive increase in indicated airspeed) bring in power and climb to appropriate safe altitude.
Environmental factors that contribute: Hot, humid, high aircraft weight, high altitude.
Settling with power is problematic because the recovery is counter-intuitive, when a pilot is faced with an accelerated descent rate close to the ground the natural reaction would be to increase power which would result in a greater rate of descent, while the solution is to lower power and increase forward airspeed, taking the aircraft towards the ground before recovery can be made.
Could the crash have occurred from settling with power, I believe so... though I couldn't say what happened in this instance because I have not studied the effects of vortex ring state in UASs (though that could be really fun -- 4 rotors to interfere with one another... could get some craziness), and I wasn't there. Settling with power is, in a helicopter, is always accompanied by sever shuddering of the air-frame, and a rapid descent made worse by application of power.
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actually,i have flown with Fizzviic and we both have experienced v.r.s. the solution to it is to either go at a moderate pace or if moving fast, move a little in any direction until you get low enough to set up to land and then just slow down and land as normal.
we both had the problem with a p-1 that had a lot of mods on it making it have to work harder and create more prop wash.
i have had v.r.s. start(wobbling is the clue) and merely moved forward while going down and the wobble stopped.
i think the key here is this was auto land right?
i have done auto land with the inspire and it was remarkably stable. if it was in v.r.s you would see a little wobble and not a straight down fall. it does sound like something failed..scary..but things fail. i will wait to see the results from dii..nobody knows anything yet i am sure.
absolutely correct..as long as you slow down and move straight down the last bit..maybe 8 ft. or so depending on comfort level.
i have come down quite fast on the p-1 as i was afraid the battery was going to die and just kept moving towards myself,then at about 8-10 ft. i slowed it and landed..sweating a bit. lol.
my experience with v.r.s. was not pretty..going straight down heavily loaded with two batteries,it got a bit unstable and i hit full up..nope..it just kept down down..a little faster even as i was just adding more prop wash. letting off the throttle might stop it,but i found just moving sideways gets it into clean air and you are good very quickly.
Bull, the advice I gave was fine and not bad. As long as you have some type of movement along with your decent you should be fine. That is if your any kind of decent pilot. You don't need to be a rocket scientist to take off, fly and land. I'm not saying your actually hitting the ground as you are moving forward, sideways etc....
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Sorry, I misunderstood what you were saying. Yes, during descent from altitude forward or sideways movement is beneficial for staying out of VRS. Landing, though, should be done vertically, with low descent rate. Agreed?
LOL glad there is still a bit of humor around instead of all the doom and gloom usually posted here.
Not sure I know the answer to that. I've encountered it mostly by rapidly coming straight down, It may have something to due with the surface one is landing on. I do know that if high enough one can often "fly" out of VRS by a rapid application of direction change (other than yaw).
to the op did you calibrate the IMU ? before flying or at all ? I know mine needed calibrating when i checked maybe that was the cause of your issue ? I still can't believe it was not posted in any on dii litature.
To stay out of settling with power (vortex ring state) descend slowly to landing spot, no lateral movement required. If descending at a fast rate for any reason, landing or otherwise, ensure you have forward movement to ensure you are moving away from the disturbed air until the descent rate has been arrested, then descend slowly to your spot. Again it takes 3 things to cause settling with power, fast descent rate, being below ETL (read forward speed is too slow), and power applied. So either use a slow descent rate, or keep forward motion, either will prevent it. Or you could land without using power... but then you would have bigger problems.
Oh, and if anyone wanted to find out at what speed the Inspire reaches ETL, or which speed to maintain while descending quickly, do the following. (I would do it but my shiny new toy has yet to arrive). On a flat smooth surface (for ground effect) increase power until the aircraft hovers just a couple inches above the surface. Without increasing power push slightly forward on the pitch control just to induce controlled forward movement. The aircraft should dip down slightly and then as speed increases it will come back up, and then start to climb. At the point at which it starts to climb out is where ETL is, fresh air is going through the rotors and increasing their performance.
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And as his name implies, he's a Killjoy.
Just kidding, he and I have been tag-teaming a bunch of Kindergartners who want to go out to play in the road.
Ha ha ha, never heard of heli driver... More like constant emergency management and control specialist Lol. But yes, guilty as charged. Nothing like turning and burning. BTW nice pickup on the screen name quad. My wife gave me the nickname, should I be concerned?
I grew up in Germany. Your wife either has a great sense of humor, or there's a little passive aggression going on.
