General Flight Instabilities

[Nybble]

Hi there!

 

I've put a few hours into flying the Mi-8 now, and have a couple of issues with the general handling. I understand it's an incomplete product, but I want to find out if it's something I am doing wrong or just a game issue.

 

Basically while in flight, I will have the pitch / roll and heading autopilot settings on. This gives smooth flight when traveling in a straight line, however after turning I notice the nose bobs up and down quite a bit regardless of any input I give it, and takes a while to settle down.

 

With the autopilot settings off, I can handle this much better, however when trying to trim it, I notice with the controls indicator open, that my trim does not really save and seems to have little effect. Sometimes it does work like it does in the huey, but once trimmed I notice the chopper seems to override my trim and set its own, and this is with all autopilot settings off.

 

So just some help, trips, tricks or an explanation would be much appreciated.

 

Thanks!

[Flagrum]

Hi there!

 

I've put a few hours into flying the Mi-8 now, and have a couple of issues with the general handling. I understand it's an incomplete product, but I want to find out if it's something I am doing wrong or just a game issue.

 

Basically while in flight, I will have the pitch / roll and heading autopilot settings on. This gives smooth flight when traveling in a straight line, however after turning I notice the nose bobs up and down quite a bit regardless of any input I give it, and takes a while to settle down.

 

With the autopilot settings off, I can handle this much better, however when trying to trim it, I notice with the controls indicator open, that my trim does not really save and seems to have little effect. Sometimes it does work like it does in the huey, but once trimmed I notice the chopper seems to override my trim and set its own, and this is with all autopilot settings off.

 

So just some help, trips, tricks or an explanation would be much appreciated.

 

Thanks!

Nose bobbing up? I've never seen this ... only one thing comes to my mind in this regard that could be perhaps of interest. You are aware that you must give rudder input to override the roll autopilot channel? Otherwise you fight the AP and that could cause the rough handling characteristics.

 

The pedal input is necessary because in reality those pedals have switches built in to detect if the pilot has his feet on the pedals or not. And if he does, the roll AP channel is (temporarily) switched off and you can bank smoothly in order to steer. (you would use the rudder pedls anyways to maintain a coordinated turn). And when the pilot takes his feet off the pedals, the AP takes over again to maintain a nice and level flight path.

 

In DCS these switches in the pedals are implemented as "if there is (at least a tiny bit of) rudder input, then feet-on-pedals are assumed".

[Cibit]

Its difficult to answer you because everyone has their own methods but generally speaking if I am turning more than about 20 degrees I would disengage the heading stabilizer and the altitude stabilizer, perform my manoeuvre get retrimmed for level flight and then re-engage the stabilizers. I never fly without the Yaw Pitch channel engaged. slight increments and trim every time making sure you also make constant corrections with collective is best advice I can offer:)

 

Sniped by Flagrum :P

[Nybble]

Thanks for the quick replies!

 

I understand for the mostpart how the autopilot works, and how it turns off yaw assistance when you give some input. I like this feature and have no issues with it.

 

My biggest problem is, as mentioned, even with the AP off, my trim seems to be changed and never holds the position I give it.

 

I had the idea that I may be doing something wrong in the start sequence, so I will fly a hot start flight, and if I have issues I will provide a track file.

[lmp]

Yesterday I noticed that the yaw autopilot can sometimes mess with the pedal trim. It tends to happen when you're overriding the yaw channel with rudder input. I can't reproduce the problem yet, but it can change pedal neutral position even if I have "rudder trim" disabled in the settings. This happens both in 1.2.6 and 1.2.7. This never happened when I had the yaw channel off. I'll try to investigate it today and report it to the devs.

 

I never noticed the bobbing you mentioned nor had any other trim related problems. Do you fly with the controls position indicator displayed? What are your rudder trim and central trimming settings?

[Nybble]

I never noticed the bobbing you mentioned nor had any other trim related problems. Do you fly with the controls position indicator displayed? What are your rudder trim and central trimming settings?

 

In special have all of the boxes unticked, so there should be no rudder trim.

 

As for the nose bobbing, that only occurs with the pitch / roll autopilot enabled. Once I come out of a turn and return the nose to level with the horizon, I can see that the autopilot is trying to get the nose level, but it overcompenstates and pushes it too far, then overcompensates again trying to bring it back. Control input does not help, and trimming has no effect

[BIGNEWY]

Provide a track the community here are always willing to take a look and give advice.

[lmp]

Yesterday I noticed that the yaw autopilot can sometimes mess with the pedal trim.

 

Ok, I figured this out. The yaw autopilot channel will start trimming the pedals once it reaches its limit of control authority. For example, if you start turning left with the yaw channel on and without any rudder input, the yaw channel will try to counter it to the right until it reaches the limit, and then the pedals neutral position will start moving to the right. It can be seen in this video:

 

 

Is this how it's supposed to work? I thought the force trim and autopilot were completely independent...

[Cibit]

That's how it works and if your rudder is in an offset position when you disengage direction auto assist the pedals will stay offset until you reengage it and turn till it hits the stop and you get the n symbol.

The bobbing is different. I was getting this problem and figure it's too much collective.

[Nybble]

Here's the track as promised.

 

It's just me flying around Batumi airbase. Initially it starts with the AP on, and it takes me a moment to get her steady. On the first turn I get a bit of bobbing. When I fly back towards the ocean I disengage the AP and can control her much better, however no matter what I do I cannot get the trim to work, even though I can hear the sound of the trimmer.

 

Then I try and land, and fail horribly.

 

If someone could watch though this (about 5 mins long) and give me some advice that would help alot!

mi8-tests.trk

[Nybble]

I did some further testing, and have encountered something even stranger.

 

While sitting on the runway, my controls indicator shows the stick being pulled AFT-RIGHT without me giving any input, which turns me to the right a bit. If I try and trim it out I have to push the stick full forward and left, and that only gets it close to neutral. If I hit reset trimmer it resets briefly then goes back to the aft-right position.

 

Is this normal behavior?

[Cibit]

Delete user input file and check control helper is of in special options

[Nybble]

Delete user input file and check control helper is of in special options

 

I had a play around and enabled central position trimmer mode. I have this off for the KA-50 and the UH-1H but for the Mi-8 it has fixed the problem.

 

Also I have turned the control helper on and off a few times, without noticing any change. What does that do exactly?

[wolle]

not at my gaming computer now, so I can't watch your track. Just want to make sure you have the "control helper" special option for the Mi-8 unchecked. If it is checked, the computer will keep the Mi-8 level and ignores any trimming you might attempt. Probably not the cause for your problems, just to make sure...

[Nybble]

not at my gaming computer now, so I can't watch your track. Just want to make sure you have the "control helper" special option for the Mi-8 unchecked. If it is checked, the computer will keep the Mi-8 level and ignores any trimming you might attempt. Probably not the cause for your problems, just to make sure...

 

That may have been the case, I did enable it temporarily because I thought it meant the controls indicators (Is there a way to make them off by default in the Mi-8??) and now it's off again and is behaving well.

[Djent33]

Thanks guys, that control helper.. hmm..

Today I switched 126 for 127 and ticked some boxes in UI options, and it was bobbing, I sow the collective stick move on its own and the trimmer went to sleep, I thought f*(.

You see I wasn’t a heli man until I tried it and now can’t get enough of it… but ‘’control helper‘’, no,no,no,no.