[REPORTED]Gun Dispersion

[cicimicikiller]

Still not fixed, first time reported 26.1.2017 which is 9 months. Let me remind you that this module is out of beta.

[cicimicikiller]

Hi guys!

We will examine this issue in detail and correct the problem.

 

Many thanks.

 

It's been 9 months, any news?

[Aries144]

I found a useful quote, with cited source that offers some supplemental information:

 

From "Flying Guns – the Modern Era: Development of Aircraft Guns, Ammunition and Installations since 1945"

 

"Accuracy of the guns varies depending on the weapon and the installation. It is measured in mils (one mil equals one metre dispersion at 1,000 m). The .50 inch M3 could manage about 5 mils. The four Mk.12 cannon in the F8U were regarded as inaccurate, reportedly achieving only 12 mils (or 3.6 m at 300 m). The F 100 with four M39 cannon could get all of the shots within 8 mils and 75% within 4 mils. The M61 is capable of about 3-4 mils when internally mounted, although the centreline gunpod used in the F 4 is less rigid and can manage only 8-10 mils."

[johnv2pt0]

For anyone interested in this thread, Belsimtek has responded:

 

https://forums.eagle.ru/showthread.php?t=195293

 

Basically, all bugs that they know about are not going to be addressed until they are done with their part of the F-18C module. Don't expect anything soon...

[Aries144]

Does anyone have a copy of that Northrup F5 maintenance manual gun accuracy image? It seems it was yet another victim of the photobucket fiasco. Belsimtek is going to need to see that when they get around to fixing bugs on the F-5 again. It seems they're very big on needing verifiable sources before they're willing to make changes.

[Ramsay]

Does anyone have a copy of that Northrup F5 maintenance manual gun accuracy image?

Here you go:

 

[PeaceSells]

Here you go:

 

 

Interesting, I always thought it would be a circle instead of a square - a diameter of 8 mil (although I don't know how relevant this is).

Edited November 23, 2017 by PeaceSells
replaced the word "radius" with the word "diameter"

[Ramsay]

Interesting, I always thought it would be a circle instead of a square - a radius of 8 mil

A circular dispersion with a standard deviation of 4 mil would have 68% of the shell impacts.

 

I'd guess, the 80% threshold takes the additional area from using a square target into account while making the target easier to construct/measure.

 

Proving the solution would perhaps be an interesting integral ?

Edited November 22, 2017 by Ramsay
Fixed SD, 8 mil diameter -> 4 mil radius, thanks to Aries144

[Aries144]

Ramsay, thank you for providing that image!

 

Regarding the "Dispersion Area" mentioned in the illustration, you're over thinking it a bit. The illustration isn't intended to be used that literally. Remember, this kind of information is intended for maintenance crews, not engineers.

 

Picture a circle on a target 8 mil in diameter. "8 mil, 80%" means 80% of rounds must impact within an 8 mil circle. If more than 80% of rounds, for a given number of rounds fired (we don't have that information), impact outside an 8 mil circle, maintenance is required.

 

8 mil, 80% would also be the minimum level of performance before parts replacement or other repairs would be required, not the norm. i.e. "If it get's worse than this, we need to fix something."

 

Please note also that "Standard Deviation" is not what is meant here, but diameter. "Dispersion Area" is naturally a circle.

Edited November 22, 2017 by Aries144

[Aries144]

Accuracy tests seen here by modifying lua file for different accuracy values and comparing with the F-5's 40 mil diameter gunsight + actual M61 Vulcan accuracy test video (same accuracy as the M39 200mm cannon on F-5)

 

https://forums.eagle.ru/showthread.php?t=198157

[Aries144]

Now updated with ShadowPlay recordings.

[Aries144]

New information incoming. I just discovered that it is possible to freeze the aircraft using active pause, decelerate time using alt z, and shoot the cannon in slow motion with no movement of the aircraft. This will make the next videos posted here as accurate as if the aircraft were stationary on the ground!

[Grisleybear]

Sorry to bump but was this ever looked into?

 

ED updated the dispersion for the guns on the F18 + F16 a few months back. Will we see any changes to the F5 or is what we have right now accurate?

 

Thanks,

 

EDIT

 

Took a look at the shell_table.lau that was mentioned earlier in this thread.

 

Seems like ED changed the Da0 value of the M61 from 0.0022 to 0.0015.

 

However, the Da0 value of the M39 is still set as 0.0022.

Edited September 1, 2020 by Grisleybear

[Schmidtfire]

Any news on this? The thread states Reported but no progress?

[RustBelt]

News? F-5 is a done deal, the only thing they seem to feel they need to do with the Tiger is maintain it as the Core updates.

 

I think it's safe to say it is what it is at this point.

[MiG21bisFishbedL]

It does seem that way. "Reported" in the sense that it's been filed away to a dusty cabinet.

[Dirkan]

Yup. It's an easy change, so it's irritating. One line per shell of the M39 in a shell_table.lua.

[blaster182]

How about it, Eagle Dynamics and Belsimtek?

 

Edited March 17, 2021 by blaster182

[bkthunder]

Lol, sorry to break it to you, but they only fixed half of the massive wind bug after years and years of reporting it. Their priorities are launching new early access products, fixing old stuff doesn't bring any money (or so it seems)...

[Golo]

Yea good luck waiting for that fix, ED has horrible track record of correcting mistakes/bugs in old modules. Wasnt it like 9-10 years it took ED to correct GAU-8 dispersion for A-10? Its laughable really.