need track replay Assymetric loadout

[greenmamba]

Hi there,

 

When trying to takeoff with assymtric loadout, For example 2xGBU-12's on one wing and 1xAGM-65 on the other, the assymetry translates to a yaw to the heavier wing on takeoff roll, it is almost impossible to bring back the airplane on the centerline. 

 

This is a serious issue that most of the times results in a rejected takeoff. I know that the F-16 is down low , even way down low on your priority list, the latest patch shows it clearly, but at least make it flyable please, even if you give it some non study sim depth for now, at least get rid of that freaking yaw to the right when applying power. 

Edited May 3, 2021 by greenmamba

[Furiz]

Maybe its drag that makes you yaw left? Wind?

 

Do you have a track so we can see whats going on?

 

[t1mb0b]

so, maybe double the weight on one side. Have you actually calculated the weight difference?

I have no idea what limits are set for real world Ops, but to me it sounds pretty stupid to attempt take off with such a significant asymmetry, and then to label what ED have modelled a bug, is a bit rich.

There's a yaw there because the aircraft is out of trim.

[greenmamba]

So you are actually serious ? You really mean it when you claim that it is alright to have an airplane yaw to the heavy wing side ON GROUND when you apply power due to assymetric loadout ? If you think i am being stupid then check again what you wrote. I am not talking about when i am airborne, again ON GROUND. 
 

Also check assymetric loadouts for the F-16, maybe i am not that stupid. 
 

What do you say about the real life an operational loadout that consists of 4xGBU-39 under one wing and a GBU-12/49/38/54 under the other ? 
 

On 5/4/2021 at 6:03 AM, Furiz said:

Maybe its drag that makes you yaw left? Wind?

 

Do you have a track so we can see whats going on?

 

I really don’t believe that the drag would outpower my rudder pedals inputs on the takeoff roll. For the wind, the winds were calm, runway axis, like 6 knots. 
 

I then edited the mission and then i put one AGM-65 G and one GBU-12. Still when you apply MIL power and then AB power the airplane yaws to the right but it is catchable with the rudder. It shouldn’t be like that. 
 

Even when i trim the airplane on the ground, it makes no difference. The imbalance should be felt at liftoff/rotation. 

Edited May 5, 2021 by greenmamba

[randomTOTEN]

I just did a takeoff under your conditions from Nellis with little problem. In fact, the largest problem I had was the imprecise twist of my inexpensive joystick. But that's not the Viper's fault. I've had more problems with directional control in the Su-25T on many takeoffs with symmetrical loads than this Viper takeoff.

Yes, asymmetry can cause uncommanded yaw even on the ground.

 

Can you share a short track with the forum? So I can see your actions? And I can exactly replicate the conditions which are causing you the problem....

[greenmamba]

Will do, this is very very weird. Thanks for testing. 

[BIGNEWY]

weight plays a factor here not just drag, but please include a short track replay showing the issue.

 

thanks

[=52d= Skip]

On 5/5/2021 at 9:56 AM, t1mb0b said:

so, maybe double the weight on one side. Have you actually calculated the weight difference?

I have no idea what limits are set for real world Ops, but to me it sounds pretty stupid to attempt take off with such a significant asymmetry, and then to label what ED have modelled a bug, is a bit rich.

There's a yaw there because the aircraft is out of trim.

 

 

 

*******

 

On 5/3/2021 at 6:36 PM, greenmamba said:

Hi there,

 

When trying to takeoff with assymtric loadout, For example 2xGBU-12's on one wing and 1xAGM-65 on the other, the assymetry translates to a yaw to the heavier wing on takeoff roll, it is almost impossible to bring back the airplane on the centerline. 

 

This is a serious issue that most of the times results in a rejected takeoff. I know that the F-16 is down low , even way down low on your priority list, the latest patch shows it clearly, but at least make it flyable please, even if you give it some non study sim depth for now, at least get rid of that freaking yaw to the right when applying power. 

 

 

What works well for me is to takeoff in MIL Power only and not to disengage NWS as I find Rudder Authority weak at low speeds.

 

 

[greenmamba]

Nice video ! This only confirms that the ground handling of the jet needs to be reviewed, will do like you with the NWS on to control for takeoff roll. At the beginning the Hornet also had this weird yaw to the left … i don’t know if this is something generig for ED modules but an airplane does not behave like that. It will veer a bit on one side or the other especially on airplanes with twin engines because of the way the engines respond, but on a single engine jet i find it really hard to believe that it veers off sharply on one side. And assymetric loading has no effect on ground handling especially not when being at low speeds on the ground. 

[t1mb0b]

On 5/5/2021 at 10:14 AM, greenmamba said:

So you are actually serious ? You really mean it when you claim that it is alright to have an airplane yaw to the heavy wing side ON GROUND when you apply power due to assymetric loadout ? If you think i am being stupid then check again what you wrote. I am not talking about when i am airborne, again ON GROUND. 
 

Also check assymetric loadouts for the F-16, maybe i am not that stupid. 
 

What do you say about the real life an operational loadout that consists of 4xGBU-39 under one wing and a GBU-12/49/38/54 under the other ? 
 

I really don’t believe that the drag would outpower my rudder pedals inputs on the takeoff roll. For the wind, the winds were calm, runway axis, like 6 knots. 
 

I then edited the mission and then i put one AGM-65 G and one GBU-12. Still when you apply MIL power and then AB power the airplane yaws to the right but it is catchable with the rudder. It shouldn’t be like that. 
 

Even when i trim the airplane on the ground, it makes no difference. The imbalance should be felt at liftoff/rotation. 

 

 

Apologies if i jumped the gun, next time i fly the 16 i will take the time to give it a go myself

[greenmamba]

2 hours ago, Desert Fox said:

Weight imbalance -> higher weight on one sides' wheels -> bigger contact surface on those wheels -> increased force transmission -> drift -> drift increases with speed.

 

Basic physics, literally 7th grade level.

 

Have you ever flwon an airplane for real ?

[greenmamba]

Just now, Desert Fox said:

 

I paid attention at school. Some others should have too i guess.

 

True that i never was the Top A student in real life, but i'm happy that i get to fly for real every day. Have a nice one ! Will pop open a beer after my flight thinking about you and your valuable life lesson !

[MAXsenna]

 
True that i never was the Top A student in real life, but i'm happy that i get to fly for real every day. Have a nice one ! Will pop open a beer after my flight thinking about you and your valuable life lesson !

Don't need no airplane to test this.
Some years ago in my old E36 on the Autobahn, 200km/h, stick my arm out, car immediately slows down and drifts to the left.
Now you do it in your airplane. Just kidding.
I haven't bothered to test it in the sim as I haven't had a problem yet.
What happens if you alternate the "asymmetricism" between left and right. Does the drift alternate as well?
Cheers!

Sent from my MAR-LX1A using Tapatalk

[greenmamba]

Hahahahaha good one ! 
 

i haven’t tried to alternate but i will give it a try. 

4 hours ago, t1mb0b said:

 

Apologies if i jumped the gun, next time i fly the 16 i will take the time to give it a go myself

No worries brother, happens to all of us. Have a wonderful day !  

[Tango3B]

4 hours ago, Desert Fox said:

Weight imbalance -> higher weight on one sides' wheels -> bigger contact surface on those wheels -> increased force transmission -> drift -> drift increases with speed.

 

Basic physics, literally 7th grade level.

True. Nothing more to add to this.

 

2 hours ago, MAXsenna said:

Don't need no airplane to test this.
Some years ago in my old E36 on the Autobahn, 200km/h, stick my arm out, car immediately slows down and drifts to the left.
Now you do it in your airplane. Just kidding.
I haven't bothered to test it in the sim as I haven't had a problem yet.
What happens if you alternate the "asymmetricism" between left and right. Does the drift alternate as well?
Cheers!

Sent from my MAR-LX1A using Tapatalk
 

Well said. And you also might have noticed that your arm was forced upwards. This is because you actually generated lift with your arm. This is a basic aerodynamic lesson, so to say. Now translate that to the originial problem reported by the OP. There's your solution. I do not think there is a bug. What actually might be an issue, though is that I think trimming the Viper sufficently precise in DCS is pretty hard and not necessarily realistc. A forum member called Spacemonkey elaborated a little more on this topic a few weeks ago somewhere here in the F-16's forum section. You can search for it if you want to know more - I don't want to dive into this, again. I would suggest to assign roll trim to a slider axis. I did it and I am able to trim out even the most interesting loadouts without too much trouble. Maybe the OP should consider giving that a try. And also the wind settings in his mission might be a problem, of course.

[MAXsenna]

Well said. And you also might have noticed that your arm was forced upwards. This is because you actually generated lift with your arm. This is a basic aerodynamic lesson, so to say.
Snip...

Absolutely correct!
One can actually play with this. If you "scoop" your hand, your arm will go up. And if you really "straight" it, like an upside down spoiler, (diffuser?), it will go down. It's actually very fun to test this. And one doesn't need to go fast either.
Better be shotgun though!
Cheers!

Sent from my MAR-LX1A using Tapatalk