HUD lines pull to the right

[maxmax]

I've encountered a strange problem. Some times at take off the plane pulls to one side, and when in the air, the HUD lines are displaced to the right. I cant use guns pipper afterwards either, it only says ccip invalid when changing to the guns mode.

 

I was thinking the HUD problem has to do with crosswind, but at take off radio guy tells me 2 m/s. So I don't think that's the problem. The ball is also centered, so it's not my rudder or my stick.

 

Any ideas?

[EtherealN]

Ball being centered has nothing at all to do with crosswind.

 

Plane pulling to one side on the ground is most likely assymetric drag. Most payloads on the A-10C is not "mirror image" and the simulator does take this drag differential into account in the aerodynamics model.

 

CCIP invalid os probably unrelated to the other behaviours you have noticed. Ensure that your elevation source is the DTS.

 

If in doubt: post a track and we'll take a look. :) (After flight, click "save track", then on the forum press "go advanced" and use the paperclip icon.)

[maxmax]

Could be assymetric drag, but i doubt it. It had crossed my mind, but as I was carriying a symmetric load, it feels unlikely. Also, it has not happened before, with the same loadout. And, as i said, there was no crosswind.

 

I will try to replicate the problem tonight. And when it happens, I'll save a track and post it.

 

It happened at every take off when playing online, also to my friend who hosted the game. The problem appeared with different loadouts. It has happened a couple of times in a single player campaign mission as well.

 

It's a complicated sim so It's probably me, and not the sim.

[EtherealN]

Symmetric load? Which load was that? (Seriously, there are very very few symmetric loads in this simulator.)

 

But yeah, see if you can pick up that track and I'll have a look.

[maxmax]

Symmetric load? Which load was that? (Seriously, there are very very few symmetric loads in this simulator.)

 

But yeah, see if you can pick up that track and I'll have a look.

 

 

Thanks, much appreciated!

[BKLronin]

I got the same "problem". I always thought it is an unfinished INU alignment but it wasn´t. I think I only have it after a manual ramp start so there might be an error there.

 

Will see

[Kaiza]

If the ball is centered then it probably isnt an assymetric load as this would displace the ball also. I would suggest that it is crosswind. 2m/s is ~4 knots, if this is all xwind, it will be noticeable on the HUD as 4 knots crosswind at A-10 takeoff speeds will create roughly 2 degrees of drift.

[bluepilot76]

Its easy to test if its a cross wind;

 

Take off and fly with ball centred whilst flying along the runway .Your nose will be pointed into the wind. Lest say to the right of centreline.

 

Now perform a 180 turn and fly back along the runway. Which way is the nose pointing? If to the left of the runway centreline, then it is a cross wind.

 

If still to the right then maybe a bug?

 

Cant test I'm at work , but I have noticed this as well, assumed it was crosswind.

[EtherealN]

If the ball is centered then it probably isnt an assymetric load as this would displace the ball also. I would suggest that it is crosswind. 2m/s is ~4 knots, if this is all xwind, it will be noticeable on the HUD as 4 knots crosswind at A-10 takeoff speeds will create roughly 2 degrees of drift.

 

The assymetric load aspect applies mainly to the ground, and it can very easily be big enough that you'll notice it, but not enough to move the ball.

 

Basically, my suspicion is that it isn't a singular thing that's happening, but rather several different things that manifest in the same way, dependent on which regime the aircraft finds itself in.

 

But I'm ready to watch any tracks you have. It could be a bug (although I personally doubt it in this case), so worth looking at. :)

[maxmax]

For me it was still to the right after turning 180 degrees. took off in one direction and turned 180 degrees over airfield. HUD was always to the right. With rudders it centered, but its kind of hard to fly sideways :)

[EtherealN]

Track track track! :P

(At debrief, Save Track, then Go Advanced here and use paperclip. :) I need to see it. )

[BKLronin]

It clearly seems to be the cross wind for me playing devils cross first mission at the moment and it changed the sides as I turned 180 degrees..

[maxmax]

Track

 

Here's a track. 2 m/s wind, HUd pulls to the right. Is it me or is it the game?

Hud_displacement_wind2mps.trk

[EtherealN]

Downloading, I'll check back with you in a couple minutes. :)

[EtherealN]

Part of the behaviour on the ground is a bug: a problem in turbulence handling in the dynamic weather engine. Second part is that the issue is aggravated by assymetric drag to the right with the payload used on takeoff.

 

The ladder slipping in flight is crosswind.

[arteedecco]

Other thing I would mention is fly the same mission again, but call the groundcrew ("\" then "F8") and ask for a rearm. Remove all weapons and external ordinance (assuming there is a "gun only" loadout, I can't remember if there is or not?) and go to takeoff again.

 

Flying the tank busting mission last night where all you have is the gun, I noticed a LOT less of this odd yawing / rolling issue. The plane was down-right pleasant to fly! :) Go figure. Even climbed like a champ!

 

Conversely, on a later mission I was loaded with Anti-Armor #9, which is quite close to symmetric (discounting TGP, ECM Jammer Pod, and AIM-9s). There was a stiff right-hand cross-wind on takeoff. (note: I do not have rudder peddals and have to use keyboard "z" and "x" for rudder input ... booo!) I switched off nose-wheel steering as I went through 50 KIAS and proceeded to drift off the runway to the right (into the wind). Not sure what the speed was, but it was strong (approx. 30 knots at the waypoints according to the CDU, not on takeoff). The HUD was way off center most of the flight.

 

Keep in mind, at low speed the crabbing effect of xwind will be greater than when you're at cruise speed.

 

I'm not sure if the sim will "give credit" for this, but using proper cross-wind takeoff / landing technique may prove useful. I tried it a little last night, but need to do more testing.

 

Crosswind takeoff technique (page 21 of 44, 5-5): http://www.faa.gov/library/manuals/aircraft/airplane_handbook/media/faa-h-8083-3a-3of7.pdf

 

I also would be curious if the SIM is over-doing it a bit (may relate to the turbulence bug mentioned previously)?

 

Possibly, in real life to pilots leave nose-wheel steering on until a higher speed if cross-winds are in excess of 15 knots (direct crosswind component)? This would allow for the rudders to be more effective before disengaging nosewheel steering.

[maxmax]

Part of the behaviour on the ground is a bug: a problem in turbulence handling in the dynamic weather engine. Second part is that the issue is aggravated by assymetric drag to the right with the payload used on takeoff.

 

The ladder slipping in flight is crosswind.

 

Thanks for the help! So it's not only me :)

 

I haven't had the same issue with other loadouts, for example 6*mav + 4*cbu97.

[maxmax]

Oh, another thing. Is 2 m/s second crosswind enough to be noticeable?

[arteedecco]

http://www.calculateme.com/Speed/MetersperSecond/ToMilesperHour.htm

 

2 m/s = ~4.5 miles per hour (mph)

 

FYI, in aviation speeds are often recorded in Knots (nautical miles per hour), e.g. the speed indication in the HUD is in knots:

1 miles per hour = 0.868976242 knots per hour (knots)

 

Therefore, 4.5 mph is about equal to

4.5 miles per hour = 3.91039309 knots per hour (knots)

 

The effect of ~4 knots from the side is pretty light. Even flying Cessna 150's / 172's, which weigh under 3500 lbs at takeoff this doesn't take much to counter.

 

An A-10 weighing (typical CAS loadout) 47,000 lbs. on takeoff would have a lot more resistance (inertia) to a light 4 knot crosswind. Admittedly the cross-section of an A-10 has a lot more surface area for the wind to act upon but with dual rudders I would think 4 knots would be quite subtle.

 

In short, you wouldn't have to do much with the rudders / flight controls to counter that light of a wind, which is why I think the sim is dramatically overdoing the xwind effect on takeoff. (possibly due to the turbulence bug???)

[Kaiza]

The effect of steady crosswind on a 172 is the same as an a-10c. Inertia will only come into play for gusts, so weight/ size is not a factor . To figure it out, it is the total crosswind factor divided by the miles per minute in air speed. 1 mile per minute is 60 knots. So at 120 knots in the hog your drift will be half your total xwind factor and at 180 it will be a third.

Edited April 26, 2011 by Kaiza

[effte]

But wind correction angle and thus airspeed is a factor. Rotating at 65 the effect of wind will be felt more than when you rotate at 100...

[arteedecco]

But wind correction angle and thus airspeed is a factor. Rotating at 65 the effect of wind will be felt more than when you rotate at 100...

 

Yep good point.

 

Also good point to Kaiza on the effect being the same on large and small planes alike. Speed is the key.

 

I still feel that the effect of the crosswind is too significant on takeoff. How do we differentiate between wind effect and the turbulence bug?

[Villain]

Thought it was just me, the plane always is intent on turning slightly to the right but its noticeable. Doesnt matter what weather im in or payloads as it does it in training and any mission ive tried its ridiculously frustrating. Its always too the right so that rules out crosswinds because it does it whilst facing any direction.

[arteedecco]

Thought it was just me, the plane always is intent on turning slightly to the right but its noticeable. Doesnt matter what weather im in or payloads as it does it in training and any mission ive tried its ridiculously frustrating. Its always too the right so that rules out crosswinds because it does it whilst facing any direction.

 

Have you gone into the Options and disabled all Yaw axis inputs?

 

I have an old X52 where the twist (Yaw) sensors on the stick are crap and when I have those inputs set in the game Options the plane jerks and yaws as the sensors flutter.

 

The fact that you're always going to the right doesn't match my experience related to wind / loadout.

 

Try w/out any weapons at all and from different ends of the runway. (if you haven't).

[Villain]

Well ive done the training missions where you dont even have a payload and its the same so thats why i ruled that out, ill try that axis inputs thing you suggested though but i dont use a joystick as the one i have is crap and only does sudden movements if that makes sense.