Collective brake and Altitude hold channel problem.

[MrYenko]

I seem to be at an impasse with the ever-lovable AFCS. It seems that even with the Altitude channel disengaged, the altitude hold mode switch (Radar/Baro) in neutral, and the autopilot command switch on the collective (Route/Descent) in neutral, the AP is still trying to hold altitude. I have to move the collective at least 20% in either direction to get any result, even using the hold-and-move method with the collective brake. Needless to say, 21% more collective than I want results in... Odd flight behaviors. (ROLLERCOASTER OF ANTI-TANK LOVE)

 

My understanding is that with the altitude channel offline, I should be having unfettered collective control inputs, is that wrong? Am I missing something?

 

:joystick:

[MrYenko]

Track attached. Note immediately after takeoff, I even tried the Flight Director mode, holding down the brake, and swinging the collective around like a madman. You can see it in the commanded blade angle indicator. Compare and contrast with the VSI.

 

I'm annoyed.

collectivebrakesucks.trk

[slug88]

Haven't watched your track yet, but if you're seeing an immediate response in the blade angle indicator, then I believe that proves that the AI isn't fighting you. As per the pilot's manual, the rotor pitch indicator shows the actual current pitch of the rotor blades, it is not showing the "commanded" blade pitch as you imply in the post above. If the VSI isn't immediately responding to the pitch change, it's probably because the auto throttle isn't able to adjust quickly enough to maintain the nominal RPM. And then of course there's the inertia of the helicopter itself; 10 metric tons of helicopter will need a bit of time to accelerate in any direction.

Edited August 11, 2010 by slug88

[slug88]

Ok, from watching the track, the answer is pretty obviously inertia. You're yanking the collective from one end to the other multiple times a second, the helicopter is simply far too heavy to noticeably respond to your inputs. I was surprised to find however that the rotor RPM stay pretty constant throughout, so it seems I underestimated the response time of the throttle in my post above. In a bit I'll post again with my own track, in which I'll attempt to show that there's a clear difference between hover hold on and off.

Edited August 11, 2010 by slug88

[slug88]

Ok, I've recorded a short track, which I believe shows that everything's working exactly as it should (also features two bonus VRS escapes in the first minute! :D)

 

So as you watch the track, you'll see me enter into a hover with the assist of autohover. Then, I will turn off the altitude hold, and you will notice that within a second or two I will be drifting downwards at a little less than 1m/s. I will then make the smallest collective input I can muster, increasing the blade pitch angle by about 0.5 degrees. You will then notice that, within a second or two, the slow descent will have turned into a 1m/s climb. I then lower the blade pitch by about half a degree, and again you'll see that in a second or two I'll be descending again. Then, to finish off, I'll re-enable the altitude hold while still descending, and you'll see the blade pitch increase automatically (no collective input from me), and I will be holding a constant altitude.

altHoldDemo.trk

[MrYenko]

First, my track was recorded towards the end of about an hour of me running into hills because I was having insufficient collective response, therefore, I was not as objective as I could have been.

 

Second, the godamned thing was in game flight mode. Made me look like a hero, in terms of stability and clean manuevers, but not exactly what I was looking for. Somehow, game flight and realistic avionics were selected, and I didnt realize that was even possible, so I assumed that since I had complex-systems, I also had complex flight-model. Not so.

 

USER ERROR.

 

:doh:

 

 

Thanks for the feedback, though. With the flight model now set to realistic, it behaves exactly as you describe, and how Ive learned it should.

 

Also, I never knew it had the nifty flip up glareshield for the HUD, so it wasnt a TOTALLY useless post. :P

[slug88]

Ah yes, that track was just full of bonus features wasn't it :D. Good to hear that your issue was resolved.

[Distiler]

Second, the godamned thing was in game flight mode. Made me look like a hero, in terms of stability and clean manuevers, but not exactly what I was looking for. Somehow, game flight and realistic avionics were selected, and I didnt realize that was even possible, so I assumed that since I had complex-systems, I also had complex flight-model. Not so.

 

USER ERROR.

 

Second time I hear that in a week. Have you selected simulation mode activated by default during the installation? (remember, there is a moment when it asks you about it)

Steam, dvd or website download?

[topdog]

I reinstalled from DVD last weekend to perform some tests; I use on realistic/sim mode settings, but once in the game and configuring it I had to specifically set them again as some game mode options were still enabled (I didn't really pay much attention as to what it was exactly that was enabled and just reconfigured as per my old install).

 

I also made/make sure to set the 'use this in all missions' option on the same screen, otherwise some standalone missions can override it on you unexpectedly too (including the missions you make in the editor yourself).

[Gadroc]

I did a re-install as well recently and even though I selected simulation mode during install it was set to game mode. Made for some eating crow as I bragged about how good I was landing at FARPS :)

[MrYenko]

I was on a fresh install on a (relatively) fresh OS install, installing from the website download, and I remember clicking simulation during installation.

[Slayer]

That checkbox doesnt work. I think after the 1.02 patch it resets some control settings.