I think I have done something wrong...

[VR Flight Guy in PJ Pants]

Still struggling and it seems there was something changed in the latest OB, may be not. Any help would be appreciated.

 

[NeedzWD40]

What's your weight and configuration? I can see an immediate cyclic motion forward and left when the wheels lift off, but beyond that the collective motion might've been too fast.

[Flagrum]

Happened to me all the time - until I made it a habit to disable the parking brake and unlocked the tail wheel.

[Devrim]

Hey. I hear you Flight Guy.

When I mentioned this issue on Facebook group, they made fun of me.  They accused me that I can't fly well bla bla, I need to check the wind bla and check the doubled axis controls etc. etc. like I'm not flying in DCS since 2009.

Anyway... I'm happy to see there're another pilots who experience this.

Thx!.

[GrEaSeLiTeNiN]

I'm guessing you are heavy and at very high MSL. Or does this happen at low MSL also? Check also if you have any double axis binds.   

[VR Flight Guy in PJ Pants]

Thank you all.

Environment: -12 degrees, no wind

Helo configuration: 100% fuel, nothing else.

Further tests -- reduce fuel to 25%, unlock parking brake and tail-wheel brake while static.

Even though if I move the cyclic slightly to the left to avoid this situation, I would say there are other problems as well.

Edited April 17, 2023 by VR Flight Guy in PJ Pants

[JSpidey]

1 hour ago, VR Flight Guy in PJ Pants said:

Thank you all.

Environment: -12 degrees, no wind

Helo configuration: 100% fuel, nothing else.

Further tests -- reduce fuel to 25%, unlock parking brake and tail-wheel brake while static.

Even though if I move the cyclic slightly to the left to avoid this situation, I would say there are other problems as well.

 

Before takeoff keep an eye on the trim ball, adjust the cyclic to keep it centered until you lift off the ground, then recenter it when wheels up to avoid overcompensation.

[Moxica]

It seem you are to careful with the collective. It needs a faster and more firm movement. "Rotor rpm high" comes from to little collective/torque.
-Try giving more collective, and giving it faster.

Edited April 17, 2023 by Moxica

[sirrah]

56 minutes ago, Moxica said:

It seem you are to careful with the collective. It needs a faster and more firm movement. "Rotor rpm high" comes from to little collective/torque.
-Try giving more collective, and giving it faster.

 

Disclaimer :

Not implying I know better and with respect, but I think that statement is not correct (or I misunderstood what you are saying).

 

First of all, rapid/firm collective movement is never really needed during take off. Quite the contrary I'd say, slow and steady collective movement works best, especially when you're still learning the Apache behavior. 

The rotor rpm high comes from to fast/much collective, not from too little. @bradmick explains it very well in this thread here: 

 

 

 

 

 @VR Flight Guy in PJ Pants; My first thoughts, when looking at your video, were:

• You might be a tad late on the cyclic correction (left) and then overcompensation when things start to go sideways (literally )
• You might want to pull your collective more gently (looks like you might have some stiction going on there, as your collective inputs appear to not be very gradually). Best way I found to learn, is to gently pull collective until she gets light on her wheels and then, with wheels still touching the ground, make very small cyclic & rudder corrections to keep her steady/straight. 

(then again, it's very difficult to draw conclusions from a video. Also, as mentioned above, double check your controller axis)

 

fwiw; I couldn't see your rudder input in the video, but I tend to give some slight left rudder input while increasing collective. At some point, you'll know how much just by feel and it'll all go automatically.

 

Edited April 17, 2023 by sirrah

[Moxica]

1 hour ago, sirrah said:

Disclaimer :

Not implying I know better and with respect, but I think that statement is not correct (or I misunderstood what you are saying).

 

First of all, rapid/firm collective movement is never really needed during take off. Quite the contrary I'd say, slow and steady collective movement works best, especially when you're still learning the Apache behavior. 

The rotor rpm high comes from to fast/much collective, not from too little. @bradmick explains it very well in this thread here: 

 

 

You might be right for all I know. It's just that the video reminded me of my first attempts at takeoff with newly released, early version of the AH64. I did what I've read, and I was way to cautious.
Now I look at the terrain and firmly pull torque until it behaves.   

[aaronwhite]

6 minutes ago, Moxica said:

You might be right for all I know. It's just that the video reminded me of my first attempts at takeoff with newly released, early version of the AH64. I did what I've read, and I was way to cautious.
Now I look at the terrain and firmly pull torque until it behaves.   

I was going to suggest something similar. One thing I noticed isn't that you need to be super aggressive with the Apache collective, but I did seem to run into issues where I was trying too much to get it to just barely go light on the wheels, and it would tip a lot in that moment. I finally just started making a pretty steady collective increase through to going off wheels, and then I could lower it a bit to kill the lift right off the ground. I had the problem of tipping over a ton like OP, but since being a bit more constant with increasing the collective on takeoff, I haven't had it happen in a few weeks now. 

[sirrah]

31 minutes ago, aaronwhite said:

I was going to suggest something similar. One thing I noticed isn't that you need to be super aggressive with the Apache collective, but I did seem to run into issues where I was trying too much to get it to just barely go light on the wheels, and it would tip a lot in that moment. I finally just started making a pretty steady collective increase through to going off wheels, and then I could lower it a bit to kill the lift right off the ground. I had the problem of tipping over a ton like OP, but since being a bit more constant with increasing the collective on takeoff, I haven't had it happen in a few weeks now. 

I do agree there's a very thin line between "fighting her" and "feeling her". And again, not saying you guys are wrong (hey it seemed to have worked for you), but increasing the collective with rough/sudden motions will only result in having to correct/compensate faster with your cyclic and rudder. 

 

Back when I started to learn the Apache, I handled the collective very gently and I was struggling to get to/stay in a nice hover.

Later/now, I can just jank that collective to the "sweet spot" and she'll very steadily get of the ground, while my hand and feet on the cyclic and rudder automatically compensate any unwanted moving. Although I usually do the latter now, it's definitely also possible/"easy" to get into a steady hover by gently increasing the collective.

At some point when practicing, you'll just "get it" and your hands and feet will work automatically 

 

(I have to add: I use VR. Years ago when I was still on pancake, I had a lot more struggles with helicopters in DCS and perhaps never really fully got them under control)

[VR Flight Guy in PJ Pants]

Disclaimer! I really did not touch the cyclic, the red dot of the control indicator moved itself all along.

[admiki]

25 minutes ago, VR Flight Guy in PJ Pants said:

Disclaimer! I really did not touch the cyclic, the red dot of the control indicator moved itself all along.

Make sure you don't have control helper enabled

[Hootman9104]

I just did some testing with and without weapons, there was no difference between the two.

If you apply very slow collective, the aircraft will begin a right roll. If you don't push the cyclic a touch left, it will roll over.

If you apply very slow collective, and use a very small touch left cyclic, the aircraft comes right on up.

If you apply medium or fast collective, the aircraft pretty much pops straight up either with or without left cyclic.

Basically what you are encountering is "dynamic rollover", because for whatever reason the aircraft rotor appears to be getting just a tad more lift on the left "retreating" side, and since the right wheel is still on the ground, it's pivoting on that wheel. If you raise it ever so slowly you can see and feel it rotate. I think most people don't notice this because they apply collective a little faster, or just automatically feel it and just barely tap the cyclic left. 

bottom line, once that wheel is off the ground, the aircraft is then "swinging" under the pendulum of the rotor, and your are automatically adjusting at that point.

Whether it should do that, not sure, it may require just a minor tweak in the flight model, but the bottom line is, you aren't reacting correctly. So either tap the cyclic left as you should see it starting to rotate, or get a little quicker on the collective.  

I personally think a little tweak is in order, as the rotor (in theory) should be applying equal lift on both the advancing and reatreating sides of the blades.

But even if they don't tweak it, there is really nothing wrong. Just commit to takeoff, don't dawdle around there, the issue is it's going into dynamic rollover by pivoting on the right wheel, and you are not reacting to it...

In my 20 years we had one dynamic rollover, and that was in the desert in a brownout condition, the pilot didn't detect a slight drift to the left as he was setting it down, and the aircraft rolled over when the gear touched the ground. That's about the only situation you should ever have a dynamic rollover.

[admiki]

5 hours ago, Hootman9104 said:

I personally think a little tweak is in order, as the rotor (in theory) should be applying equal lift on both the advancing and reatreating sides of the blades.

It's called translational tendency.

Tail rotor is pushing your tail to the right to counter torque reaction from main rotor. Since it's behind and above CG, reaction is yaw to the left and roll to the right.

[macedk]

On 4/16/2023 at 11:57 PM, Flagrum said:

Happened to me all the time - until I made it a habit to disable the parking brake and unlocked the tail wheel.

+1

[pii]

On 4/16/2023 at 6:40 PM, Devrim said:

Hey. I hear you Flight Guy.

When I mentioned this issue on Facebook group, they made fun of me.  They accused me that I can't fly well bla bla, I need to check the wind bla and check the doubled axis controls etc. etc. like I'm not flying in DCS since 2009.

Anyway... I'm happy to see there're another pilots who experience this.

Thx!.

Recently when I take off the 64 seems to be caught by the gear and dragging along the ground which will make you tip over. If you look at the external view you will see the tires are below the surface and, I believe, that is what causes the drag/Tip-over you see in this video. And if you manage not to tip over you will be rocking back and forth like you are on a boat. 

[JSpidey]

Brad discusses the rolling motion you experience.