Why is there such a significant rearward blast from the 30mm cannon?

[Braeden108]

 

The gun sends as much of a flash backwards as forwards. I'm not aware of any other gun that does this. Is there just so much gas that the breach is opening and sending it backwards too? Or is this to counter the recoil?

[Northstar98]

The Tunguska kinda does it too, it's probably blast from the breech. Who knows, maybe it helps absorb some of the massive recoil.

 

[Nodak]

Recoiless design, minimize the recoil less wear and tear and improved accuracy, both for the gun and the helo.

[Fri13]

Not just that crazy flames, that will blind the pilot at night and will make wearing NVG little useless as it is bright as day on moment of shooting....

 

But look at that recoil as well. At high fire rate you have massive recoil downward. So you are not wanting to use that thing.

 

Take the low rate and you get nicer 1-2 shots per trigger and you become better by sniping targets here and there.

 

Will be interesting to see how accurately ED has modeled that recoil.... 

[Dragon1-1]

1 hour ago, Fri13 said:

Not just that crazy flames, that will blind the pilot at night and will make wearing NVG little useless as it is bright as day on moment of shooting....

That's all right, since the cockpit lighting isn't NVG-compatible, anyway. 

 

The gun is far from recoilless. At high ROF it'll jerk the helo about quite a bit. I suspect the flash in the GIF is edited to make it look more spectacular, and even if it isn't, it doesn't seem to be a recoil compensating system of any kind, just a flash from the breech. 

[Fri13]

11 minutes ago, Dragon1-1 said:

I suspect the flash in the GIF is edited to make it look more spectacular, and even if it isn't, it doesn't seem to be a recoil compensating system of any kind, just a flash from the breech. 

 

I don't remember seeing the flames such massive from the original video, but the muzzle flashes look minor compared to those rear flames... 

 

Anyways the whole cannon is on fire when firing. The original video has the cockpit at night, and it is flashing like nothing. You barely can see anything else than just flashing when firing even when it is at side.

 

[unknown]

5 hours ago, Dragon1-1 said:

I suspect the flash in the GIF is edited to make it look more spectacular

Nope:

 

But it might be weather/lighting dependant or different ammuntion?

 

[pepin1234]

maybe is a new ammunition for new generation Mi-35. We gonna get Mi-24 from 80s. just my guess.

[Kerberos]

The fire at the rear of the gun are the hot fumes from the breech accumulating. That’s why it can predominantly be seen at the high rate of fire. This fire does not absorb any recoil.

[sirrah]

No expert here, but isn't the pilot just making some pitch corrections/input here during shooting?

 

I mean, if the recoil is really this bad, it'd make the gun quite ineffective wouldn't it?

 

Looks like at 0:59 and 1:25min, you see much less recoil.

 

Again, no expert, just wondering

Edited May 24, 2021 by sirrah

[Lurker]

6 minutes ago, sirrah said:

No expert here, but isn't the pilot just making some pitch corrections/input here during shooting?

 

I mean, if the recoil is really this bad, it'd make the gun quite ineffective wouldn't it?

 

Again, no expert, just wondering

 

There is absolutely no reason to fire it at that high rate of fire, unless you wan't to impress girls or scare off insurgents. With only 250 rounds in the cannon, and the huge amount of recoil it produces at a high fire rate, it would be an absolute waste to use it in that way. Those are 30mm shells, probably HE shells at that, and from what I've seen from the interview with PilotMi8 it's very, very accurate at the low fire-rate setting. 

[sirrah]

Just now, Lurker said:

 

There is absolutely no reason to fire it at that high rate of fire, unless you wan't to impress girls or scare off insurgents. With only 250 rounds in the cannon, and the huge amount of recoil it produces at a high fire rate, it would be an absolute waste to use it in that way. Those are 30mm shells, probably HE shells at that, and from what I've seen from the interview with PilotMi8 it's very, very accurate at the low fire-rate setting. 

So if you keep the trigger pressed a long time, the nose would actually come down this far?

[Lurker]

Just now, sirrah said:

So if you keep the trigger pressed a long time, the nose would actually come down this far?

 

That would depend on the ROF setting. At 300 rpm, I doubt you would even notice the depression. At the highest rate of fire, I would imagine it's like a small retrorocket is mounted in your nose. 

[WinterH]

There's an old IRL video of showing one firing at high rate of fire, and the nose gets shuffled all around the place :).

 

We'll need to stick to low rate of fire for the usual aimed point target shooting. I'd guess high fire rate will come up when going high speed, popping up and putting lots of rounds on an area and turning back kinda deal. Looking forward to experiment with it.

 

It was the same with Ka-50 too anyway, low fire rate for point targets, and high for area saturation or quick snapshots. Only, this time high fire rate is A LOT higher  600 rpm vs 2400ish I think.

[26-J39]

The gun will certainly be a handful, i'm looking forward to it.    Point to note is that on the KA-50 the gun is hung close to the COG of the helo to minimize induced pitching from the recoil.

Also being slung from the side of the helo, the recoil induces a yaw.

 

Now the Hinds gun is slung from a more forward position so the recoil affect will be more significant than the KA-50, also to the side so we will have to anticipate both pitch and yaw when firing the gun.

 

Now add that high rate of fire and you will be in for a roller coaster ride.

[Frag]

10 hours ago, unknown said:

Nope:

 

 

The 80's call, they want their porn movie music back.

Edited May 24, 2021 by Frag

[Sealpup]

47 minutes ago, Frag said:

 

The 80's call, they want their porn movie music back.

 

Alan Parsons is not porn music.

Now if you would calmly wait right there, an Inquisitor will be speaking with you shortly.

[Frag]

9 minutes ago, Hyena said:

Alan Parsons is not porn music.

Now if you would calmly wait right there, an Inquisitor will be speaking with you shortly.

 

Holy hell you do know your music!

 

Didn't want to hijack the thread, that music just made me giggle considering it was played along war machines demonstration.

 

Back to the thread LOL!

[Fri13]

15 hours ago, WinterH said:

There's an old IRL video of showing one firing at high rate of fire, and the nose gets shuffled all around the place :).

 

We'll need to stick to low rate of fire for the usual aimed point target shooting. I'd guess high fire rate will come up when going high speed, popping up and putting lots of rounds on an area and turning back kinda deal. Looking forward to experiment with it.

 

 

(It was said to me that is a real simulator using a modified DCS World.... http://avia-ts.ua/ there is btw Mi-17V-5 action too)

 

So in that real simulator the pilots are utilizing simple single tap to get 1-2 rounds on target. Just place the CCIP on the target and one shot, correct if required and repeat.

So likely for a difficult to spot targets and as well grouped targets with plenty of soft targets near by it is short burst to just saturate the vertical distance area with shells.

 

 

 

15 hours ago, WinterH said:

It was the same with Ka-50 too anyway, low fire rate for point targets, and high for area saturation or quick snapshots. Only, this time high fire rate is A LOT higher  600 rpm vs 2400ish I think.

 

The benefit of the KA-50 gun placement is that it is closer to CoG and so on far more accurate than those other helicopters cannons.

You don't need a high speed fire rate if you are accurate in the first place.

And instead making KA-50 gun as area of effect weapon, they use rockets for that purpose. 

[Weta43]

The degree of flash is probably also related to what camera is used.

Most cameras are more sensitive to infra-red than the human eye, but some have better filters to compensate for that.

If you think about what setting fire to brandy in a pan on a cooking show video looks like (huge red bloom) compared to doing it in real life (small blue flame) you'll get what I mean.

[Fri13]

3 hours ago, Weta43 said:

The degree of flash is probably also related to what camera is used.

Most cameras are more sensitive to infra-red than the human eye, but some have better filters to compensate for that.

 

All cameras has very effective IR filters, we are talking about 99.98% filtering in usual. Some cameras has such level weaker IR filter that you can utilize them as a IR camera without performing IR conversion (removing the IR filter from the filter stack front of the sensor) by just using a IR filter that will pass only IR light. 

But even those cameras doesn't pass enough IR spectrum to be visible at all, it is negligent amount (ie, you have in direct sunlight a exposure of 1/8000, f/8 and ISO 100, and with IR filter to get a somewhat acceptable photo you have 2-3 minute exposure with f/2.8 and IO 100)

 

3 hours ago, Weta43 said:

If you think about what setting fire to brandy in a pan on a cooking show video looks like (huge red bloom) compared to doing it in real life (small blue flame) you'll get what I mean.

 

That is effect of the lighting. It might sound stupid at first but photographing a flame you need stronger lighting. It is question of the balance. A red color is just 1/4 of the digital cameras capture capability. The normal RGB bayer filter is 1/4 of red, 1/4 of blue and 2/4 of green. So green is most sensitive and detailed color that can be captured. 

The red is as well very problematic as it is longest wavelength and sensor will clip it first before other colors. Why photographing with a digital sensor on the red light is very challenging, especially if you have a purple light where you are mixing red and blue as you get two opposite ends of the wavelength and camera needs to create the color that doesn't exist, hence magenta (purple) is non-spectral color. 

Our brain invents out of the thin air many of the colors, like the purple color. It just does fancy educated guess that our eye sees red and blue light but green is missing, so brain invents a color. Our eye doesn't even see a red, as it is just interpreting the yellow-green cones are active without the green and blue etc. 

But it is a subject of many topics where colors has different meanings across different classifications depending from who you ask, a scientists, artists, average joe, biologist etc. Like many doesn't agree even with the fact that black is not a color as it is absence of light.

 

We can manipulate light to some point, but flames like gun muzzle flashes doesn't turn their colors so much, but we can make them look more visible by having a slower shutter speed for the framerate so each frame is exposed more (or less) and get better visibility of fast short period flashes.

It is similar to human eye and brain to "burn" the very fast exposures. Example the fighter pilots were tested for their capability identify target shapes in fast exposures.

IIRC it was over 1/10'000 of a second flashes where the pilots were still able to identify silhouette and so on aircraft type, that is a faster than a strike of a flash.

Our brain and eyes are just so slow that while we can quickly recognize, identify and react to things we see (like bug flying in to our eye when cycling 30 km/h speed) and we have reaction time to close the eye lid just by seeing the bug 10 cm from our eye. But then when we see a very short period flash of light, it can last seconds in our vision and mind even when it is long time gone.

 

 

[Weta43]

  

  

On 11/11/2014 at 5:22 PM, Weta43 said:

F-15 plane at different times of day through different cameras.

English Electric Lightening.

 

Same alcohol car doing burnouts 20 seconds apart through different cameras.

 

Not saying you never really get that plume of flame, but some cameras pick up infra-red better than the human eye

 

added alcohol flame in water bottle - same thing through different cameras. Through your eyes it looks more like the one on the left.

 

 

 

Edited May 26, 2021 by Weta43

[Grievo]

On 5/24/2021 at 3:06 PM, sirrah said:

No expert here, but isn't the pilot just making some pitch corrections/input here during shooting?

 

I mean, if the recoil is really this bad, it'd make the gun quite ineffective wouldn't it?

 

Looks like at 0:59 and 1:25min, you see much less recoil.

 

Again, no expert, just wondering

 

Probably the pitching moment caused by the recoil. The thing basically hangs off the main rotor, so if you bring in a rearward force right at the bottom of the pendulum, it's going to want to pitch forward.

[Lithion]

The strong fireflash at the base of the cannon is probably due to being of a revolver design.

The multiple breaches never make as good of a seal as a single battery design.

 

Nvm it's not a revolver design

Edited May 28, 2021 by Lithion

[WinterH]

1 hour ago, Lithion said:

The strong fireflash at the base of the cannon is probably due to being of a revolver design.

As far as I know, GSh-30-2K is not a revolver cannon. It has two barrels with one chamber each, recoil from one charges the other, but breeches themselves are pretty well sealed I think.  From a cursory look online, comparing muzzle velocities and lengths of GSh-30-2K seems to support this because they have almost the same length and muzzle velocity, and 2A42 isn't a  revolver cannon either. As far as I know no current Russian autocannon use revolver cannon design.