Need advice - Landing = Descending + Deceleration? For me ... it equals VRS :(

[Flagrum]

From an other thread:

For me it is easy to avoid VRS as I concentrate on not hitting too high a negative VVI whilst decelerating.

 

Sounds reasonable, maybe even easy. But not for me. I just can't manage to decelerate AND descend. If I descend, I can't manage to get rid of speed and if I manage to lose speed, I am unable to descent - I rather gain altitude.

 

What I do: I lower the collective so that I carefully and slowly lose altitude. Now I also want to decelerate and I slightly pull back the stick to an AoA of 5, maybe 10 degrees. I am decellerating now, fine, but now I am not losing altitude anymore!? So I lower the collective a bit more. Fine. Now the nose goes down and while I gain speed again, and, I don't know ... at some point either I've dropped the collective too much and I start to fall out of the sky or I come to a stop at 1000 feet and ... well, either start over again or just try to slowly descend ... which always ends in a VRS crash.

 

Obviously I am oversteering/overcompensating, I am not precise enough. I just can't find the balance between cyclic and collective to maintain a more or less stable approach.

 

If I do only minmal inputs, like 1-2 milimeters at the collective or at the stick, I just fly and fly and fly and never get even remotely to where I wanted to land. Usually the Caucasus hinders me then at some point in time to go on with that ...

 

If I use more input, like 5 milimeter-wise, best I can accomplish is bouncing around like a yo-yo. Also not really helping ...

 

Has anyone any advice for me of what or how to train this?

 

PS: I am using a G940 with all axes linar and no curves

 

PPS: Oh, and btw: I have absolutely no problems with landings in the Ka-50! Dampening and Altitude Hold seem to do wonders there for me ...

[fjacobsen]

I guess most hwo have problems landing are doing a too steep approach.

 

Though helicopters can land vertically, he normal approach is just like with a normal fixed wing aircraft. Instead of landing You will end up hovering at the spot where You would have touched down.

Offcourse speed has to be lowered alot more during the approach.

[159th_Viper]

Post a track.

[borisff]

I had also plenty of VRS. Less now following figure 3.19 of the manual:

don't fly in the red zones.

To go below 40 knots -> you must be first below 100 feet.

To go below 100 feet -> fly above 40 knots

When near 100 feet and near 50 knots, slowdown without losing

altitude, when anticipate the shake arroud 20 knots, put some collective

at the early stage of the shake.

Use Rctrl+Enter helper all the time.

 

NB: I had also an issue with my pro USB throttle, sometimes get some eratic

collective inputs leading to vrs, solved by a calibration.

novrs.trk

[Flagrum]

I just can't get the transistion right when I reach about 40-20 km/h. Everything is more or less fine, I descend slowly, I lose speed slowly ... but then around those dreaded 20 km/h everything happens so fast: I lose speed quickly (yes, the gauge is not linear, but I think, my deceleration rate is really suddenly increasing), I come to a stop and then the descend rate also suddenly increases and even if I try to anticipate this and pull the collective a bit, I can't avoid to get into VRS. There is a delay until the airframe reacts to my input, of course. But there is no time for that, as I am then already in VRS. If I pull the collective a bit earlier, I would only just stop descending or even start gaining altitude again ...

 

To me, the margin between "approaching" and "VRS" so so damn tiny ... :(

Huey VRS.trk

[Cedaway]

I'm reading this too with interest 'cause my landings are more or less 'crash controlled' style at the best :) It's the transition phase between translational and hover state that causes me the most trouble...

[borisff]

The track shows IMOO a lack of colective when it starts shaking near 20 kts,

try to put more colective as soon as it starts shaking.

Also may be check your colective curves, try a linear one for the colective.

[Flagrum]

I'm reading this too with interest 'cause my landings are more or less 'crash controlled' style at the best :) It's the transition phase between translational and hover state that causes me the most trouble...

Thats exactly my problem. :joystick:

 

But, borisff, I watched your track carefully and then compared it to mine. I found something interesting: you seem to use a bit more collective all the time, even - or especially - when landing. Atm I can't wrap my head around it how you manage to slow down and descend with what it seems to me about 50% more collective than what I use. But I guess, that might be the key to my problem? Too less collective and thus I get into "setteling with power" state? I haven't really understood that concept as by now, but intuitively I'd guess, I am flying way too narrow (outside??) to the envelope here?

Edited June 15, 2013 by Flagrum

[borisff]

The governor has some delay, when you put more collective, you have the needed more blade angle but not yet the power for that angle,

there is delay for the governor (2-4 seconds) to get correct RPM for the rotor.

Looking your track put more collective 4 seconds sooner as you do,

just before the shake occurs arround 20 kts, or try arround 25 knots.

[lanmancz]

I didn't fly Huey for some time now but I got back to it this week and I must say my landings got much better. I used simple training method - start from parking hot on some airport, takeoff, fly around the airport and try to land at the runway heading markers (ie. 09 & 27 on Senaki for example). The letters make a nice practise target and you can do it dozens of times until you get it (using respawn if you crash). My guess is that you guys are doing too much things and too fast without proper control of the aircraft (first train flying at certain altitude and speed until you get a good control - 40 kts, 60 kts, 80 kts). You have to split the movement into several parts. First I decelerate when I'm about 1km away. This means pulling back on the cyclic and lowering the collective so the vertical speed is about 0 (or little positive, it's ok) and speed should be dropping. I then ease of on the cyclic and add a little collective to *prevent* from speed dropping too much. I then keep this balance and continue to decelerate (and descent if im high) at about 40 knots (-500 fpm max) until I'm very close to the target. Then I let it decelerate more by pulling back on cyclic and lowering collective (and then ease off again to prevent it dropping too much). This WILL require more collective soon because I will loose the transitional lift, also left pedal will be needed when you're really slow. You HAVE TO BE ready for this, in fact I use it to my advantage sometimes - when Im too high I let it loose the lift a little to loose some height but be ready to compensate for it sooner that too late (or you're risking entering vortex ring and since you're so low it usually means crash). Keep and eye on that VSI, when it's shaking it's bad. Also I recommend decelerating slowly so you don't loose the lift suddenly but gradually. The rest is just practise I guess. For me the most important instruments during approach and lading are speedo and VSI. I don't really look at anything else. The key thing really is as someone mentioned before - anticipation - I know that I will lose transitional lift when my speed drops bellow 40 kts so during approach I won't let it drop so low. When I'm near and I need to delerate I am ready for it, watch the VSI and compensate with collective (and correct with cyclic and pedals) to keep my speed and vertical speed correct so I land (somewhere around:D) the mark.

 

PS: My landing are still a rough so I'm no master but this is how I train and do it and it woks well. Also I recommend having 20-30 curves on cyclic and pedals and using central trimmer mode (and trim, trim, trim!). This way I can do all those small adjustments around the center that are needed but without using center trimmer mode impossible to do on my crappy stick. Also I recommend having the control indicator on (RCTRL+Enter) - helps me a lot as well.

Edited June 15, 2013 by lanmancz

[hassata]

What helped me is to stop thinking I'm flying a helicopter and to start imagining I'm in a single-engine prop. Glide it down and grease it on.

[Vlerkies]

I just can't get the transistion right when I reach about 40-20 km/h. Everything is more or less fine, I descend slowly, I lose speed slowly ... but then around those dreaded 20 km/h everything happens so fast: I lose speed quickly (yes, the gauge is not linear, but I think, my deceleration rate is really suddenly increasing), I come to a stop and then the descend rate also suddenly increases and even if I try to anticipate this and pull the collective a bit, I can't avoid to get into VRS. There is a delay until the airframe reacts to my input, of course. But there is no time for that, as I am then already in VRS. If I pull the collective a bit earlier, I would only just stop descending or even start gaining altitude again ...

 

To me, the margin between "approaching" and "VRS" so so damn tiny ... :(

 

You need to anticipate it to a degree, you know (as you indicated) where it will occur. When your speed hits 20 and you are decelerating you will start to fly like a stone if you don't catch it.

 

I sorta got to grips with it like this.

Take the first instant action free flight mission.

On the runway in the center there is a square piece of gravel there, use it as your target rather than landing in the fields. It gioves you a visual reference and will help you reference what it happening a bit easier.

 

To practice, before attempting to actually land, approach that point and reduce speed and altitude and practice coming to a stop/hover over that point (or close to) but doing it at about 100 agl.

 

It will give you more time. If you yank the collective back it makes matters worse. You need to gently increase the collective as you hit the 20 mark to catch it with some right rudder.

lnd.trk

[Flagrum]

Looking your track put more collective 4 seconds sooner as you do, just before the shake occurs arround 20 kts, or try arround 25 knots.

I will try that, thanks!

 

The key thing really is as someone mentioned before - anticipation - I know that I will lose transitional lift when my speed drops bellow 40 kts so during approach I won't let it drop so low.

With a non-FFB stick I would not even be able to lift off ... ;) But thanks to my G940 I have one problem less at least.

 

But I guess, what you said is really key here - and I understand borisff's advice in a similar way: "anticipation" ... I guess I have to start "reacting" already before something happens.

 

What helped me is to stop thinking I'm flying a helicopter and to start imagining I'm in a single-engine prop. Glide it down and grease it on.

That's how I would like to fly this beast - just "naturally letting it happen". But for me, the Huey is still so unintuitive - at least in the situation described.

 

 

Today I am fed up with crashing ... lol. But for my next lesson I put "Anticipation" on my schedule. Actually the 3 hours today, watching the reactions of the helo, already helped me quite a bit. Although, I find it all very difficult. It all happens in such a small corner of the flight envelope ... *sigh* ... well then, "Anticipation" and ... ofc "practice, practice, practice", eh? ;)

 

Thanks guys!

[Vlerkies]

2 more, my attempts at high speed approach over a set lz.

clnd.trk

clnd2.trk

[Mogster]

The quite severe instability and shaking that occurs as you transition from forward flight to hover in the DCS Huey doesn't help along with the aggressive VRS.

 

I've found that carrying a bit of forward motion helps a lot and the beta FM seems quite forgiving to landing while moving forward. I still find pinpoint landings in confined areas too much of a lottery for my taste though.

[SimFreak]

Park yourself on one end of a runway, take off and accelerate to 80. Then decelerate into hover. Repeat until you can do this reliably and do it high enough to fix own mistake without cratering.

 

_Pdoi3CDTyA

[TimeKilla]

Thanks SimFreak good video.

[sorcer3r]

Thanks SimFreak good video.

 

+1

Yes, I think best way to get in hover is without flying circles or curves.

 

 

 

2 more, my attempts at high speed approach over a set lz.

 

I prefer a more "direct" approach. Then you lose not much time:

 

[Vlerkies]

 

I prefer a more "direct" approach. Then you lose not much time:

 

 

Yup, nothing wrong with that m8, nice :thumbup:

[Flagrum]

I prefer a more "direct" approach. Then you lose not much time:

 

Wha...? What kind of sorcery is this, good sir?? :huh:

[159th_Viper]

Wha...? What kind of sorcery is this, good sir?? :huh:

 

Anticipation :)

[sorcer3r]

Wha...? What kind of sorcery is this, good sir?? :huh:

 

Thanks. For me it helped a lot to put the stick between my legs when I fly the huey so that I can move it very easy...

(Ambiguity unintended. :wub:)

[hansangb]

damn...nicely done! gotta go practice some more!

[TimeKilla]

@Flagrum, I think this is a really good topic you have brought up I've went as far to make a video covering some of the points you have made and hope you and others might watch it and give me some feedback.

 

I've went from thinking yeah no problem, I will do this and that and land like that to being surprised at how hard it ended up being.

 

The overall feeling that I was left with was that I needed a lot more landing practice.

 

[Rogue Trooper]

Sorry if this was already stated:

The rudders also need to watched. When you slow below 20 knots and start to move through transition the helicopter starts to shake and yaw to the right, naturally you apply left pedal too stop the right yaw; This increases power to the tail rotor but decreases power to the main rotors. So during transition you are loosing lift from the main rotors and the application of the left pedal also causes another loss in lift... double trouble.

 

Again, sorry if this has been sorted and I am repeating something.