Aircraft flight Aerodynamics

[Bosco19 198]

Wow! That has a familiar ring! I don’t think there is a real aircraft I have flown that couldn’t be trimmed to hold heading and altitude at least for a minute or so. Even my simple open cockpit Experimental could hold that long, and it used a bungee cord that slid up and down the stick to trim for altitude. THE most frustrating thing to me about MSFS is that, unless you employ the AP, it’s just like you described - I can’t take my hand off the stick to do anything without the AC departing from altitude in one direction or another. Setting pitch trim with a hat switch is also a complete guessing game. This ruins any hope of trying to fly from a chart using good ole pilotage. 

[marsman2020 1,310]

The best solution I have found for trim is to get it as close as I can with my hat switch buttons, then make small adjustments to the throttle to get it to maintain an altitude.

I still think it's a lot more fiddly then it should be.  I haven't ever flown a GA aircraft but reading some pilot reports it seems like it's typical for about 60% of the impact of a trim change to be pretty much instant, and the rest settles down pretty quickly.  Where as in MSFS the aircraft will happily phugoid all day long.

[snglecoil 1,828]

@Bosco19, 100% agree. Trim behavior is by far the most frustrating. I haven’t found it to be any better in other sims either. I’m hoping that a good trim wheel will make a difference, but I’m not optimistic. 

[Dazzaboy 81]

As far as Iam concerned its a great sim that will only get better . The DEVS commitment thus far is very encouraging . 

[Bosco19 198]

There is obviously some unrevealed factor being applied to the aircraft models that make them depart from level flight over very short periods. Wind can affect an aircraft without upsetting trim, whether it be horizontal gusts, or flows, or rising/falling air columns. The AC may change attitude temporarily, or lose/gain altitude, but it should still return to level flight. As mentioned, speed changes can upset things - increasing or decreasing lift would cause an attitude change, and you would have to adjust trim again. As Marsman suggests - it's just too damned fiddly. I feel like the bulk of my attention is applied just to keep the aircraft level. I'll have to try the method of throttle application and see if that improves things.

[Glenn Fitzpatrick 3,798]

The odd thing is not every aircraft is hard to trim. The default C152 is ok for example but the default Cirrus is awful. The payware Jabiru, despite being inflicted with typical MSFS craziness in ground roll, braking and stalls, is rock stable when trimmed, whereas the payware YMF-5 heads for the ground the instant you are not paying full attention.

There is a definite issue but it is not consistent.

 

The concern is that rather than address the actual cause of the problem they will "fix" the issue with some ad hoc work around, the same way they "fixed" the CoG and instability under braking issues by making heavy braking impossible.

Edited January 25, 2021 by Glenn Fitzpatrick

[rob0203 689]

I will come back when they fix it for now the planes are hard to even keep on the ground while taxiing. Even when I changed the sensitivity of my rudder pedals.

[Nyxx 6,993]

3 hours ago, rob0203 said:

I will come back when they fix it for now the planes are hard to even keep on the ground while taxiing. Even when I changed the sensitivity of my rudder pedals.

lol, I've read some rubbish but thats right up there.

Edited January 25, 2021 by Nyxx

[tweekz 2,165]

1 hour ago, Nyxx said:

lol, I've read some rubbish but thats right up there.

I think he's refering to the twitchiness on take-off roll. I can't quite put my hand on it, but inputs are translated too direct in MSFS.

Same with surface effectiveness at low speeds. I feel like there is just too much authority when flaring. It feels a bit better since the X-mas update, but it is still there.

[Nyxx 6,993]

54 minutes ago, tweekz said:

I think he's refering to the twitchiness on take-off roll. I can't quite put my hand on it, but inputs are translated too direct in MSFS.

Same with surface effectiveness at low speeds. I feel like there is just too much authority when flaring. It feels a bit better since the X-mas update, but it is still there.

No idea, but the M20 taxis takeoff roll is great and also land, taxi etc. No probelms at all. Nothing. Nore with any other aircraft.

[honanhal 1,420]

3 hours ago, Nyxx said:

lol, I've read some rubbish but thats right up there.

Maybe it's an issue of needing to change my setup in some way, but I have to agree with Rob here. This is one of my (relatively few) frustrations with MSFS. I don't have rudder pedals, which makes using rudder and/or ground steering a real exercise in frustration. Super twitchy using the keyboard to steer and it is genuinely hard for me to keep some aircraft (especially the CJ4) on the taxiway sometimes! I would give anything for an autorudder like in FSX/P3D where I could use my joystick to steer on the ground.

James

[rob0203 689]

1 hour ago, Nyxx said:

No idea, but the M20 taxis takeoff roll is great and also land, taxi etc. No probelms at all. Nothing. Nore with any other aircraft.

But with my rudders pedals Thrustmaster if I only move a little bit to the left or right the plane just move ridiculously to the left or right. Tried changing dead zone sensitivity but still behaves weird. It is with M20 also! 
 

Am already simming for more than 20 years with home cockpit setup, so I know some stuff about it 😉 and really want it to work! But with MSFS it looks great but there are a lot of frustrations everytime!

Edited January 25, 2021 by rob0203

[Nyxx 6,993]

1 hour ago, honanhal said:

Maybe it's an issue of needing to change my setup in some way, but I have to agree with Rob here. This is one of my (relatively few) frustrations with MSFS. I don't have rudder pedals, which makes using rudder and/or ground steering a real exercise in frustration. Super twitchy using the keyboard to steer and it is genuinely hard for me to keep some aircraft (especially the CJ4) on the taxiway sometimes! I would give anything for an autorudder like in FSX/P3D where I could use my joystick to steer on the ground.

James

If your using key board then, thats just terrable and am sure its really bad. You could buy a second hand joystick....anything and make it an axis for rudders. Anything cheap will do, anything is better than key board.

24 minutes ago, rob0203 said:

But with my rudders pedals Thrustmaster if I only move a little bit to the left or right the plane just move ridiculously to the left or right. Tried changing dead zone sensitivity but still behaves weird. It is with M20 also! 
 

Am already simming for more than 20 years with home cockpit setup, so I know some stuff about it 😉 and really want it to work! But with MSFS it looks great but there are a lot of frustrations everytime!

I have no idea why you cannot keep you aircraft center lined M20 etc. IMO its two things or one or the other. A) your not smooth on controling your rudders. B) You need to set up your rudders better to suit your needs.

Here are by Rudder setting, they might help. If your still all over the place keep adding curve to dull down your over correctness. Small smooth movments are key. I have never worn shoes or anything with my rudders just socks. You "feel" a lot more.

Unlike when controlling a real aircraft you can "feel"

Edited January 25, 2021 by Nyxx

[tweekz 2,165]

19 minutes ago, rob0203 said:

But with my rudders pedals Thrustmaster if I only move a little bit to the left or right the plane just move ridiculously to the left or right. Tried changing dead zone sensitivity but still behaves weird. It is with M20 also! 

That's what I'm talking about. It feels like MSFS takes the inputs and directly translates them to actions. The resulting forces might even be correct, but in nature there is some sort of inertia that smoothens out those reactions - the result is not instant. It takes some time to accelerate the motion.

And no - tinkering with input settings is not the solution. It must be done in the model.

Edited January 25, 2021 by tweekz

[bobcat999 8,482]

I tend to start on the 'few clouds' setting, where surface level winds are around 4 kts.  I have adjusted rudder sensitivity so I can keep the aircraft fairly straight, but the magnitude of the lateral forces on the aircraft from the engine (on initial roll) and wind are quite surprising to me.

I think it is now well noted that the effect of the wind on the aircraft on the ground is overdone, like some of the other effects (icing etc.)  how much overdone, I don't know.  Maybe a real pilot could chip in and comment.

and as some have said, even in light wind, no turbulence, and with wing tanks balanced etc. occasionally I have found the aircraft in an ever increasing bank after just looking at a chart for 20 seconds. 

I am not a 'proper' pilot, but I thought aircraft had more inherent stability that this once trimmed. 

I notice the Just Flight Arrow displayed this tendency of an accelerating, wandering bank angle in Xplane as well though.  That required  a bit of rudder trim in the cruise, but even then it was unstable and wanted to topple over into a bank one way or the other if left unattended for a short while.  Are real light aircraft this unstable?  That same Arrow is the new MSFS model we are waiting for, so it will be interesting to see how that turns out! 

Note my controller dead zones are fine; I have checked for control deflection and there is none.  Some aircraft are worse than others, so maybe it is just the individual flight dynamics for each one, as I find the default Cessna's and the Carenado Mooney aren't too bad at all.

Edited January 25, 2021 by bobcat999