Are these planes this twitchy in real life?

[Keto Ketchup 240]

On the topic of editing flight_model.cfg and other plane-specific files, if I copy these files into the Community Folder, will that override the default plane or will it create a "new" plane with my own preferences? I don't mind editing certain things in the Official folders (like adding my personal callsigns to planes), but once I start monkeying around with the flight model, I'd prefer to keep this separate rather than risk corrupting the original.

[robert young 2,897]

1 hour ago, Keto Ketchup said:

On the topic of editing flight_model.cfg and other plane-specific files, if I copy these files into the Community Folder, will that override the default plane or will it create a "new" plane with my own preferences? I don't mind editing certain things in the Official folders (like adding my personal callsigns to planes), but once I start monkeying around with the flight model, I'd prefer to keep this separate rather than risk corrupting the original.

I don't think you can just put a cfg file in the community folder. You would need a package. You're perfectly ok to make a backup copy of the default flight_model.cfg within its original folder. I make two - one in the simobjects\airplane folder and another backup on a different drive or desktop for safety.

[eslader 1,823]

16 hours ago, G550flyer said:

It's like it's two different flight models on the ground and in the air.

That's why I was wondering if maybe the sim treats the wheels like variable-lift wings. As you go faster and friction is supposed to be reduced, maybe the sim accomplishes that by making the wheels themselves "wings" with heavy "downforce" switching to lift as you go faster. Then when the gear is no longer in contact with the ground, those fake wings are switched off which means you no longer have an artificial lift component at the nose and the plane stops rotating. It might be a way for them to simulate tire/tarmac physics without having to actually simulate it, but it gets exposed when those wings suddenly get switched off once they're no longer needed.

 

Just spitballing as to the possible cause.

 

19 hours ago, robert young said:

Fs2020 is showing FOUR TIMES the realistic roll rate in best possible conditions. FOUR TIMES!

Huh. I hadn't messed with the Extra so I did some testing. It's even weirder than you state. The first roll gets you 360 degrees in a little less than a second - fairly close to reality. But the instant you hit that 360 degree mark, it's like you just found 50% more aileron and you go up to the extreme roll rate. It's almost like it's getting confused over the aerodynamics and putting you into a genuine spin after the first roll. 

 

Edited September 12, 2020 by eslader

[Nyxx 6,994]

14 hours ago, robert young said:

I appreciate that, but your post appeared to be a direct answer. Apologies if I misunderstood.  I HAVE told others here how to do temporary fixes, both via numerous PMs and posts, so I am not just firing off complaints, and I am working very hard on a mod (now over 120 hours work) but it is a complete makeover so it is taking time to do properly. I'm not publishing it until it is as perfect as it can be. The rest of my posts are about persuading others that I think they are wrong when they say the f/ms are fine. They are entitled to their views but this is a forum for opposing views.

What Aircraft have you put 120 hr into Rob?

[pstrub 998]

22 hours ago, n4gix said:

You are precisely correct sir!

I would also point out that in every aircraft.cfg file there is a line indicating the flight dynamics WIP status. There are four possible values; -1, 0, 1, 2...

with -1 meaning "not done at all", 0 meaning "first pass" up through 2 meaning "complete/done". Not a single one of the 30 aircraft in Premium Deluxe are noted as "2."

That should inform all of us of how Asobo views their status!

Now this is interesting! However, I took a quick look at 2 aircraft (A320, B747), and now they have wip_indicator = 2 ... Maybe it got "hot-fixed" for the Sep 02 update? Anyway, I agree that all of them probably need a good bit of work still... 

Interestingly, there's also a file named target_performance.cfg where they seem to store the performance numbers against which the aircraft were tested internally... Haven't taken a detailed look at it though, so no idea whether the numbers in there make sense, and whether they actually match the performance of the aircraft in MSFS.

Edit: Just noticed, there's a second wip indicator in the [FLTSIM.0] section, which isn't =2 in the aircraft.cfg files... as opposed to the one in the [GENERAL] section... So yeah, looks like they don't trust their flight dynamics yet 😉 

Edited September 12, 2020 by pstrub

[G550flyer 1,052]

@Keto Ketchup

Here is the other aspect that I did not go into detail with. It's the control inertia or control lag that I mentioned. I have two good examples that demonstrate it's effect. First, lets look at air refueling.

Typically, I'm going against a tanker with new peeps and see this behavior occasionally. So there we are at the pre-contact position stabilized and ready to move forward. The pre contact position is about 50ft behind and can take about a half minute to get to contact taking your time. I normally have a hand on the glareshield and the other one on the back of the throttles on the quadrant to feel how much throttle input is being made. With my peripheral view, I can see how much input is going into the yoke. As you close on the tanker, I can see the new peep doing what I call yoke cardio. They are pumping it left right and fore aft constantly. I make no mention of it because this is a teachable moment and great lesson for them to learn. I continue telling them to keep the AR light capsule centered on the tanker flying the reverse ILS and telling them where the flap canoe, antennas and outboard engines should be on the tanker and windscreen. I know they are not really hearing me because they are doing this intense gym workout with the yoke. You hear the boom go overhead with slip stream noises and our boom operator starts calling feet position of the boom from our UARRSI. You hear that normal ca thunk and the tanker booms states "contact boom interphone". Again, I'm explaining the sight picture and where references should be and telling them not to focus on the PDIs(pilot director lights). Suddenly we are moving aft and I don't see the cardio happening anymore. I don't even feel throttle movement. I mention they will fall off as we approach and exceed the aft limit. As we continue aft, I state, "my aircraft" as I know the pilot flying is exhausted. You look over and they are sweating and breathing hard. The throttles are all clammy. I then ask to move 300 feet back away from the tanker and there I start some instruction. I have them watch and I then snap the yoke left and right quickly. I ask, did the jet move? They respond, no. I then snap the yoke fore and aft and ask the question again, they respond no. I then go into detail explaining that pumping the yoke does nothing because the jet never has time to respond. By the time the jet is ready to move, you have taken the input out. Many new peeps will make that mistake during AR and on approaches. The only time you may find yourself intentionally pumping the yoke/stick is when you are in gusty winds or rough air. In this case you are canceling out those pitch and roll moments induced by the rough air.

What I described above is typical of what you will see in new or inexperienced pilots. They just have yet to figure that aspect out. I will now explain the approach effect as it's more pronounced.

Just like in AR, you will find some peeps who will start doing yoke cardio on approach in calm air. This usually leads to over controlling and chasing instruments. This is due to control inertia. The plane will take a potato or so to respond to your input. Now, some may think, If i put in a large input, the plane will readily roll instantaneously. Well, to a small degree, but what you really get is a larger roll rate when it does move. That's how you can get yourself in to PIO quickly. Once it starts rolling, it wants to continue rolling requiring you to put in opposite input to stop the roll because you overshot. But, now it is rolling the opposite direction because you left it in too long and the cycle continues. This is why in flying you have to anticipate your control inputs. You also have to use small inputs or just enough depending on what you are doing. If I am a little bit off course, I'm going to drop in a small input to get the plane to roll some where up to 5 degrees bank. Then I will anticipate the input to get it level on a small correction of heading. As I approach the course again, I am going to anticipate an input to get a slight bank that will have me roll out on course. Small inputs and anticipation helps you deal with control inertia and allows the plane to coast to your target. Small corrections are key, I don't have to be there this instant, just a small correction back to heading, course or altitude requiring less input. You will also find inertia in power changes.

Last thing I will touch on is the landing behavior from what you see in most planes. Again, disclaimer as my experienced is comprised of jet aircraft and maybe some of the prop peeps can add what they see in their aircraft.

Here is what you may see on approach, threshold on down. This will give an idea of what you feel in as far as control. I'll touch quickly on engine response. Weight will be a factor in aircraft with large variances in weight. At heavy weights, the aircraft will lag with push and pull of power. At light weights, the response will happen quicker. For example, lets look at the flare a moment. Let's use my beloved DC10 for example. At heavy weights, I have to get that power off earlier and quickly because it will lag in response. At light weights, I have to leave power in longer and pull power slower because it will respond quickly. If I pull power too early, its going to run out of airspeed and drop in on me. To deal with the issue, we use a technique call "10% of your gross weight". If I'm at 400K, we start the flare at the 40ft call out. If I am 300K, we start it at the 30ft call out. It performs this way through out the flight regime. It causes you to anticipate power inputs and use power targets. In that jet, on a 3 degree glide in landing configuration, we use 10% of your weight plus 32. So if I'm 400K, I am looking at setting 70 to 72% on the N1s as I start down the slope and configure. Some use % or a specific fuel flow for certain phases of the approach so you can set it, tweak it and forget it.

On approach with power, I like using the knob width technique. It's actually the length of the throttle knobs fore and aft, but we call it knob width. Most throttles will have an inch or 2 inches of length. For small speed corrections, I use a knob width and leave it for a couple of potatoes to see what it does. If I don't get the change I want, I add in another. Once I approach my target, I take half of the total input out. The trend continues with small inputs as you don't want to over control dealing with response lag. Now for the behavior short final.

Once you are all nice and trimmed, you will see about 600 to 800 feet per minute depending on the glide path angle(jets). The aircraft is actually flying it's self, you are just making minor inputs to keep it on aimpoint and glidepath. Once approaching the threshold, plane dependent, you will get rid of your wind additives. At a minimum, you will have a 5kt additive which you plan to bleed crossing the threshold. As you lose this 5 knots, you will incur some nose down tendency. For each 5kts of airspeed change, you are looking at a degree of pitch change. You will have to add a little back pressure for the change if you don't trim it out. Next, about half of your wing span, you will enter ground effect. This makes the nose wants to drop, at least in all of the aircraft I have flown. Now, you have a little more back pressure. You will approach your flare height and start to flare. The flare is a 2 to 3 degree pitch change. In slick, high lift aircraft, that change is 2 degrees. Typical of the gulfstreams I fly. Now, they are very slick requiring power to be pulled at 50ft in a GV and 100ft in a G550. They will not slow down and if you pitch more than 2 degrees at 20ft or have power, you will float easily 2500 to 3000ft down the runway. As you can imagine, there is a pronounced definite flare. If you did not trim from threshold to touchdown, you have some back pressure on the yoke. Some peeps in the DC10 flew the whole approach with a loaded yoke. They preferred this because they could finesse the flare and not worry about over flaring. I never trim from the threshold to touchdown because I like the back pressure from the speed loss and ground effect. I feel it gives me more control in the flare. Once I add in back pressure and attain the landing attitude, I become a pumper. I pump the yoke giving little inputs to maintain that attitude. Flight manuals will tell you to never trim in the flare, you run the risk of the nose rising and costing you a tail strike. Quickly, lets address fly by wire aircraft. Those aircraft suffer from control lag also. Even though the aircraft interprets your inputs, the aircraft still has to respond to the input. They feel the same as conventional. Where you see the difference is in trim. You are not constantly trimming as you do in conventional aircraft. Now, this would impact the flare regime. Their systems are design to start a nose down tendency to simulate the back pressure gained inside of the threshold. Third party developers mess this up in flight sim. They instead run the trim down on you and when you start to flare, you are out of authority because of the trim change. 

There is one plane that I have heard that can get twitchy in the roll axis as I think about it. Its the 757. The summing bar that controls when and how much flight spoilers are used have a sharp curve. There is a point in which the rate of spoiler lift will increase. If not careful, it can lead to wing rocking on approach. The pilots just have to be cognizant of it and minimize large inputs when not needed. In rough air, it wouldn't matter because the plane is all over the place any way. I heard that was fixed in the 767.

Hopefully this thread has given perspective when you are dealing with flight sims and wondering what might/should be expected. Sorry for the book.                

Edited September 12, 2020 by G550flyer
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[LHookins 3,118]

5 hours ago, eslader said:

The first roll gets you 360 degrees in a little less than a second - fairly close to reality. But the instant you hit that 360 degree mark, it's like you just found 50% more aileron

So in other words, the aileron effectiveness is actually correct, but there's something else happening after you complete the first roll.  It would be nice if people reporting problems would tell us this.

Thanks for posting.

Hook

[robert young 2,897]

2 hours ago, LHookins said:

So in other words, the aileron effectiveness is actually correct, but there's something else happening after you complete the first roll.  It would be nice if people reporting problems would tell us this.

Thanks for posting.

Hook

Not for me. I get no increase or decrease in roll rate. It is pretty much uniform. A quick fix is indeed to simply reduce the aileron effectiveness in the Flight Tuning section but there are more detailed parameters that will improve things in addition (too convoluted to go into here).

[Slides 1,552]

On 9/11/2020 at 5:21 PM, G550flyer said:

We were up at the high 30s dodging storms, fighting dutch roll and getting worn out hand flying for 9 hours.

Great anecdote. I always smile when some people, including pilots, say that flying is easy and super stable. In reality, I'm sure many of them haven't hand flown a long flight in years, if ever. 

[HighBypass 2,339]

Rick! Thank you for your lengthy and detailed posts. I for one, enjoyed reading them.

On 9/11/2020 at 10:21 PM, G550flyer said:

The leg was only 9 hours to cross the ocean. Who needs AP we thought...

I reckon Klasjet needs to offer you a job! https://www.aeroinside.com/item/12945/klasjet-b735-at-madrid-on-apr-5th-2019-navigation-malfunction

[G550flyer 1,052]

6 minutes ago, HighBypass said:

Rick! Thank you for your lengthy and detailed posts. I for one, enjoyed reading them.

I reckon Klasjet needs to offer you a job! https://www.aeroinside.com/item/12945/klasjet-b735-at-madrid-on-apr-5th-2019-navigation-malfunction

Any Time Bypass,

Stories like this just make you scratch your head. You would think as soon as it was noted that the First officer's AP was not working as expected, you revert and turn it off.

[FlyBaby 659]

On 9/11/2020 at 2:02 PM, robert young said:

Yes control setups are important. But the whole point of the OP's subject goes way beyond that. For example the default FS2020 Extra and Cap, at FULL DEFLECTION (so it does not matter what you control setup is - full deflection IS full deflection) aileron demostrate 3x to 4x the rapidity of roll speed compared to the real aircraft (PLEASE look at the video link provided above!!!!). The Extra (which I have flown several times) is capable of 400 degrees roll per second, but that is with almost instant, two handed, agressive, input. In reality the figure is more like a complete roll in one second, unless you are doing a snap roll.

Fs2020 is showing FOUR TIMES the realistic roll rate in best possible conditions. FOUR TIMES! 30% out is rather extreme. But 400% too fast is very extreme. This has NOTHING whatever to do with control setups, but I fear I'm going to go blue in the face trying to get this across.

And yet you missed where I wrote...

"Its about fine tuning the response to be more realistic. I have not yet flown the aircraft referenced by the OP (and I recognize that he is referring to control surface deflections as opposed to joystick throw)"

If you are going to quote me....read it first...

 

 

[robert young 2,897]

6 hours ago, FlyBaby said:

And yet you missed where I wrote...

"Its about fine tuning the response to be more realistic. I have not yet flown the aircraft referenced by the OP (and I recognize that he is referring to control surface deflections as opposed to joystick throw)"

If you are going to quote me....read it first...

Sorry about that. I did understand your point. I was emphasising that the OP was referring to excessive aircraft roll etc whatever the control sensitivity.

Edited September 13, 2020 by robert young

[charlie130 196]

On 9/10/2020 at 12:33 PM, Keto Ketchup said:

So I've tried some of the acrobatic planes, the last one being that pretty red biplane. Holy cow are they twitchy and sensitive! At first I thought perhaps this was due to the sim being too sensitive in how it reads my flight stick, but I watched the ailerons while performing very mild banking moves with the stick, and they barely move, yet my plane goes into a snap roll. I basically have to fly with my fingertips if I want to fly normal-like. Even when I want to do things like a single snap roll, I have to be very ginger with the stick lest I end up performing 10 neck-breaking rolls instead.

So my question is, being a flight sim pilot only, is this realistic, or is there something wrong with the flight model? My brain just can't fathom that such a tiny deflection of the ailerons (which I'm looking at when I try these maneuvers) would result in such a drastic change in attitude. If real planes do behave this way, then I'm amazed anyone can fly them with precision, as I'd think the mild vibrations from the engine twitching the stick would constantly jerk the plane around.

PS - other planes like the Cessna and TBM feel fine to me.

In my opinion yes, the flight model is very sensitive. Definitely put profiles on your stick and rudders, I use 33 on y and X.

If you want to see how sensitive the flight models are, put your own weather on and have winds with crosswinds and gusts. Try 290/15 with gusts at 20 with a slow frequency of gusts. Then fly and watch the behaviour?

I'll be interested to see what the second update patch adds to RW weather. I've sent in a ticket to Zendesk. The models are very sensitive and factoring in winds makes them fly like they have no inertia.

Just my observation after flying it for a week.

Cheers.

Edited September 13, 2020 by charlie130
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