investigating Incorrect weight for all wingtip payload

[ustio]

so in this thread 

. it explain that the smokewinder is too heavy. however i went a bit further to test all of the wingtip payload.

 

the testing method is simple. have an F-5 with a single asymmetrical wingtip loaded with smokewinder as a baseline and see how the aircraft would react without touching the controls. and then compare it to other wingtip payload. as you can see with the track below, it seems the aircraft react the same way(in terms of roll rate) as the smokewinder when loaded with asymmetrical pylon for every loadout which brings to the conclusion that all of the wingtip payload weight are incorrect.

 

now if i were to guess, in the original thread, it was found that they input the wrong weight of 200 Kg instead of 92kg, I believe this is a unit error that they assume they put 200 pounds instead of kilo

 

smokewinder.trk 9b.trk 9p.trk 9p5.trk ACMIpodtrk.trk catm.trk

[Flappie]

Hi. I don't understand your testing method. Aircraft will always turn to the non-empty wingtip side, as long as the payload weight is above zero.

I've just checked the weights in the mission editor. They are very close to their real life counterpart:

• AIM-9B weighs 163 lbs in DCS (real one weighs 155 lbs)
• AIM-9P/9P5 weighs 190 lbs in DCS (real one weighs 190 lbs)
• "Captive AIM-9M" weighs 190 lbs in DCS. The Captive Air Training "AIM-9M" (CAP-9M) missile being used to simulate the size and weight of a standard missile, let's assume the real one weighs 190 or 191 lbs.

Source: https://www.ausairpower.net/TE-Sidewinder-94.html

I'll report the AIM-9B weight as a very low priority issue (we're talking about a 8 lbs difference here).

Edited February 26, 2023 by Flappie

[Flappie]

@ustio I've read your message from the other thread. I guess what you meant was not that weights were incorrect, but rather than the F-5E is overreacting to asymetric payload. I agree, but I'm not sure how to prove this to devs. Any idea?

[Bucic]

@Flappie

First things first, does the bug report poster claim specifically some sort of timing this issue might have surfarced? That'd be one good piece of information for the devs.

Second, I'd compare using non-wingtip ordnace imbalance. Starting from a configuration that introduces grossly greater (IRL) imbalance compared to the wingtip ordnace scenario.

[Flappie]

I've just asked devs to check the AIM-9 effect on aerodynamics for the following aircraft: F-5E , A-10C, F-16C, and F/A-18C.

[Tiger-II]

On 12/13/2023 at 1:42 AM, Flappie said:

I've just asked devs to check the AIM-9 effect on aerodynamics for the following aircraft: F-5E , A-10C, F-16C, and F/A-18C.

What was the outcome? F-5 and F-16 are both noticeably degraded by having AIM-9 on the wingtips, and AFAIK, the F-16 is degraded regardless of which station it is on. There is too much drag from the missile.

The drag problem also affects other weapons, and pylons. The JF-17 has a particularly bad time with dual pylons and missiles, as the combined excess drag is huge.

Edited April 4, 2024 by Tiger-II

[nairb121]

This section of the -1 manual (page 6-13) states that the effect of asymmetrical wingtip stores is negligible:

[Flappie]

Thank you. I've added it to the internal report.

[SparrowLT]

On 5/22/2024 at 10:29 PM, nairb121 said:

This section of the -1 manual (page 6-13) states that the effect of asymmetrical wingtip stores is negligible:

 

 

 

 

 

Thats funny as every time i fire the first sidewinder is nearly like if have droped a bomb .. sudden roll to one side and nasty wobbling when on high alpha

Edited May 24, 2024 by SparrowLT

[Daemoc]

On 4/4/2024 at 5:28 PM, Tiger-II said:

What was the outcome? F-5 and F-16 are both noticeably degraded by having AIM-9 on the wingtips, and AFAIK, the F-16 is degraded regardless of which station it is on. There is too much drag from the missile.

The drag problem also affects other weapons, and pylons. The JF-17 has a particularly bad time with dual pylons and missiles, as the combined excess drag is huge.

 

I have no idea what a real F-5 with a single wingtip aim9 should feel like, but this has been my observation as well. At first I thought the rolling moment was a result of asymmetric weight and tried to counter with aileron, which never seemed to behave. Again, no real world experience here, but it just felt off. It got to the point that I would just launch both missiles at the same target because having the single winder was more of a liability in a turn fight.

After while I noticed that if I counter the "roll" with rudder instead of aileron, it was easier to control at slower speeds which points to asymmetric drag rather than weight.

I don't know how you could test something like this let alone prove anything right or wrong, but my gut tells me the wingtip stores create too much drag.

[IvanK]

On 5/23/2024 at 6:29 AM, nairb121 said:

This section of the -1 manual (page 6-13) states that the effect of asymmetrical wingtip stores is negligible:

Bump. The F5E FM still has this over the top wing drop after 1 Sidewinder fired.

[Raven (Elysian Angel)]

On 12/7/2024 at 2:52 AM, IvanK said:

Bump. The F5E FM still has this over the top wing drop after 1 Sidewinder fired.

Indeed. The Mirage F1 one also suffered from over-the-top asymmetry for a while.

[Bucic]

In the same document by the AGARD "agency" there's some hard data on wingtip loadout asymetry affecting stability, inertia etc.

https://forum.dcs.world/topic/373745-f-5es-aoa-capability-is-too-low-new-document/

 

Multiple download sources:

https://duckduckgo.com/?t=ffab&q=agard+AD-A029+071+stall+spin+PROBLEMS+OF+MILITARY+AIRCRAFT&ia=web

Some examples attached.