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[Robot]

Hi, in my installation of the game, The P-47D-27 and the P-47D have intense side to side recoil when firing the guns. It is so intense that at 150 meters I cant hit a ME 323 Gigant. This does not effect the P-47D-10 or the P-47D-22. This also effects the BAT P-47D-30 and the BAT Thunderbolt MK.II, but none of the other BAT thunderbolts. When I revert the game back to stock 4.12.2, the problem goes away, but comes back when I enable BAT again. I have done several different wipes and installs and I still have the problem. Does anyone know what's going on?

[WxTech]

This issue was present for more planes back in ye olde tymes. As I understand it, this has to do with guns firing in a sequence that emphasizes recoil alternately between the left and right. This wouldn't happen if the firing was balanced. Odd how such a pronounced exhibition of this old annoyance should be present these days, given that effort was directed at its amelioration quite some years ago...

[vegetarian]

I think it was introduced as part of the Jugs Reloaded pack - from the readme...
"In order to achieve historical accuracy you'll find all P-47 bubbletop versions in this pack which do not have the fin fillet attached yet (this is the D-27, D-27 late and D-30) to show these bad manners now. Be prepared to spray your ammo in the horizontal plane with these beasts..."
I get around the issue by only flying the Razorback Jugs 

[Robot]

This issue was present for more planes back in ye olde tymes. As I understand it, this has to do with guns firing in a sequence that emphasizes recoil alternately between the left and right. This wouldn't happen if the firing was balanced. Odd how such a pronounced exhibition of this old annoyance should be present these days, given that effort was directed at its amelioration quite some years ago...

I've have heard this from someone from a discord server, but if i disable BAT and stay on 4.12.2, the problem goes away.

[Robot]

I think it was introduced as part of the Jugs Reloaded pack - from the readme...
"In order to achieve historical accuracy you'll find all P-47 bubbletop versions in this pack which do not have the fin fillet attached yet (this is the D-27, D-27 late and D-30) to show these bad manners now. Be prepared to spray your ammo in the horizontal plane with these beasts..."
I get around the issue by only flying the Razorback Jugs 

I guess that explains it. Is there any way of disabling it? I like the razorbacks but not having the nice 150 octane boost starts to become an issue past mid 44. And I don't want to loose BAT

[vegetarian]

To get around the extreme yawing, in VPModpack I uninstalled the Jugs Reloaded Pack that I has installed, and installed P47D_PitsV4 by Poncho. That gave me upgraded cockpits and allowed me to play P47D campaigns with a reasonable chance of hitting the enemy . I haven't tried with BAT as yet as Jugs Reloaded is coded in the base SFS files, and that is beyond my very limited skill set. Would be great to find a way to resolve the issue. I started Torre's Battle of the Bulge campaign in BAT 4.1.3, but gave up in frustration after a few missions.

[WxTech]

I refuse to believe a P-47 was ever this awful in swing of yaw when firing guns. Here's how I reason it.

Consider the very worst case. Suppose all 4 port guns fired together, then the other 4 starboard guns fired together, back and forth like that, alternating in groups of 4. At a fire rate of something like 12 per second, tbe resulting rate-of-bangs would be double that, or about 24 per second. It would be utterly impossible to set up a far slower swing in yaw remotely like this, whose glacially slow period is of order once per second. You would get a *far* smaller-amplitude jackhammering vibration. There would still be an effective neutralizing by virtue of the rapidity of the operating and opposing impulses. Inertia would impose itself.

To get a self reinforcing ~1/sec oscillation, the guns would effectively have to alternate between left firing and right firing at a rate of the same ~1/second on each side, or ~2,/second as a system.

Whatever yaw instability the dorsal fin addressed would not be due purely to gunfire. Not by a long shot. The adverse yaw would not be so materially augmented in the manner portrayed here. The addition of a dorsal fin was to address an underlying directional instability that would be equally present while not firing guns.

It would be statistically pretty unlikely to have this worst case scenario of maximal oppositional synchronization. On average, the guns would be rather nearer to balancing each other while firing. And even *if* such yaw departure could be induced, it would not be of the same amplitude every time.

To me, this simplistic, exaggerated 'force' is an abomination. I'll bet that early Jug guncam clips don't come remotely close to exhibiting this swing of 4 to 5 degrees (a 100 mil reticle is 5.7 degrees in diameter--a handy measuring device.)

[vegetarian]

I agree, it makes the bubble top P47D very frustrating as a gun platform in BAT. They are a lot more stable in BoX and DCS.

[SAS~Storebror]

Anyone here who ever sat in a P-47 bubbletop and fired the guns in the air?
See.


Mike

[Griffon_301]

That argument can be used against you as well Mike 🤪

Seriously now: I also do not think that the yaw was that bad in real life as it is depicted in the Jugs pack, but then again it does not make the late model Jugs unusable either...the key is to keep speed up in the pass, use short bursts and make these count...I do not fly the Jug that often but it is not overly hard to kill targets with that amount of firepower...

[WxTech]

The heavy 8-gun Jug and the lighter 6-gun Kittyhawk or Mustang; what's the fundamental difference? Ratio wise in the number of guns to weight, they don't differ too greatly. What physical mechanism should cause a yaw departure several times worse in one versus the others? For the Jug, a 33% increase in gun count, which moreover is countered by the mass of the crate, should not induce a swing moment *several times* worse. It really is to invoke some magical force. The gun fire rates are the same, and the slugs have the same velocity and mass, and the gun displacement from the /c centerline are not so different.

Basic physics tells us what to expect. Perhaps a 50% greater departure in yaw, not 500%.

While none of us has enjoyed the delicious prospect of flying a Jug and firing its guns    , we are at the same time subject to the uncertainties of an increasingly remote history. After all, look at the hand wringing over even fundamental characteristics of plane performance. Issues such as induced yaw while firing guns would be nice to see documented with measurements. If we have no such data available, and are reliant upon anecdote and otherwise non-rigorous reportage, a certain skepticism might be warranted.

In the end, a more advanced bird like the Jug would be expected to have such a nasty vice as this to be predicted, or if found after the fact, a quick solution implemented, if as simple as removing two guns. To send into combat such an ammo waster would be foolish.

In the end, an appreciation of physical principles and the known performance of not fundamentally different platforms suggest we are suffering a needlessly exaggerated degradation.

Again, how does extra vertical stabilizer area, which addresses low frequency yaw instability, magically improve a jackhammer vibration of frequency many times more rapid? It makes no sense.

[WxTech]

Here's a viable way to induce this kind of oscillation in yaw. Mount a single 40mm or 57mm under each wing, eafh firing at about 1/sec, alternating left and right. It would require an impulse frequency not very different to the yaw frequency in order to maintain it.

Think of a corrugated dirt road (like you get in the Ozzie Outback). Drive at low speed, and the car bobs up and down like to scramble your guts and brains. The corrugations are near to synchronized with the car's natural oscillation frequency. Drive faster, and the de-syncing of these frequencies means smaller vertical 9scillations. At a certain speed, the wheels kind of skim the crests of the corrugations,cand the ride becomes much smoother, albeit with a high frequency vibration and no small noise.

The plane's naturally low frequency for yaw instability is very like the car. The rattling guns are the road corrugations skimmed over at high speed.