Was the side-mounted cannon genius or a mistake?

[Volk.]

I've read they mounted the 2A42 on the side, near the centre of gravity to compensate for the recoil of the BMP-2 gun.

From all the sources I've seen, the 2A42 is the same calibre (30mm), but longer barrel and muzzle velocity than most other Attack helicopters

 

 

 

Couple of years later the Mi-28 comes out using the same cannon, but chin mounted, with larger arc it can shoot in. From the limited videos I've seen, I can't visually tell that the Havoc has worse recoil or flight characteristics than the Ka-50/Ka-52 when firing, or that it's a reduced version of the 2A42.

I have no Idea on actual accuracy differences between the platforms.

 

 

 

*If* all the above is correct, was the mounting for the Mi-28 just better designed (more time spent I guess), or did the Black Shark get by then with am economically cheaper and lighter mounting by doing the side mount and hoping coaxial rudder speed would compensate?

[Buzzles]

The better (stiffer) the mounting, the better the long range accuracy. Pretty much true for all guns, so the KA-50 is probably more accurate at longer range as I suspect it probably has a more ridgid mounting.

 

As for why, I can only guess. I suspect you might get more concrete info in the Russian side of the forum.

 

It and the Mi-28 were both planned to replace the Mi-24. With rocket/gun runs being the for CAS and they both can do that, maybe the utility of the chin turret mount is better for it over raw accuracy? The Mi-24P with its huge fixed cannon is a thing though, which sort of discounts that thought.

 

Or it could simply be a design choice, with the KA-50 planned to be used a bit more as a standoff weapon so more focus is on ranged accuracy? Or it could simply have been a choice to give more space in the nose to sensors?

 

The Russian side can probably shine more light on the subject.

Edited October 7, 2020 by Buzzles

[Quadg]

The mount in the ka-50 takes advantage of the flight characteristics of the ka-50 with its counter rotating setup.

 

You don't need a gun that aims to the side when you can do flat yaw turns at any speed.

And you can also use more aggressive side slips than a traditional helicopter. because there is no loss of tail rotor effectiveness.

so it can use "the funnel" (circle-strafing), where the aircraft maintains a line-of-sight to the target while flying circles of varying altitude, elevation and airspeed around it.

 

The mount closer to the centre of gravity takes more advantage of the accuracy of the 2A42

than the chin mount further outside the COG.

 

so each mounting suites the helicopter its mounted too. with both designs having pro's and con's

 

the KA-50 has the large shkval system taking up most of the nose

[fudabidu]

IIRC there were concerns about increased drag caused by the tall rotor assembly, so the gear was made retractable (leaving no space for a turret, but less drag) and the cannon was moved to the side (less drag than a turret).

 

Recoil will always have an effect on your aim unless the cannon is perfectly in line with the center of mass. You can either design a ridiculous looking helicopter (in the 1980s!), find ways to compensate for it or your gun will just spray all over the place.

 

If you've watched videos about Soviet helicopters you'll have noticed they prefer running attacks and if this was the doctrine at the time the Ka-50 layout makes perfect sense. The cannon is mounted as close to the center of mass as possible to minimize the effect recoil has, airflow and autopilot will stabilize the helicopter significantly and the limited cannon traverse compensates for any remaining deviation.

It's not like you could make use of a turret in the Ka-50 anyways. The Shkval can only look 30° to both sides. Using only the HMS would make the gun inaccurate due to the lack of range information and you'd loose almost all your situational awareness.

 

So, assuming running attacks where the doctrine, I'd call it "Soviet genius". It gets the job done very well without any extras.

 

The Mi-28 still has to deal with the same kind of problems, especially if you start turning the turret, but the solutions stay largely the same. In the end it's not a huge difference to the Ka-50.

[Volk.]

Thanks - that's interesting. I suppose the larger arc swiveling turret works better for a 2 seater than it would have for the single-pilot Ka-50.

 

 

 

ps. if the laser is armed, then holding down Uncage Shvkal does appear to fire the laser periodically even without pressing lock, so 'wild gunning' it will have some ranging - just not fully accurately ranging until you tap lock I guess.

[fudabidu]

The Shkval can only look 30° to both sides. Using only the HMS would make the gun inaccurate due to the lack of range information

 

If the target is outside the Shkval limits, you can't get range information, so a turret wouldn't be a significant advantage.

That's what I was trying to say

[Isegrim]

Its been made to keep the Profile of the Helicopter as low as possible to compensate the size of the vulnerable (possibly exposed) area caused by the additional height of the Helicopter caused by the coaxial rotor design.

 

Wich in fact means that you can shoot with your Gun as soon as your target is visible in the Optics (Shkval) if you are behind a part cover (lets take for example a wall).

 

With an additional turret for the Gun below its nose you would need to climp even further out of cover to not shoot into the cover(Wall).

 

If you look at the side profile of the Helicopter you will notice the the Gun is actualy mounted higher in the overall height of the Helicopter than the Optics(Shkval).

 

This video shows how wobbly the Gun in fast firing mode actually is.

 

 

The recoil and accuracy part from above makes sense ... yes... but its more like being factors, but not the reason why the KA-50 has a gimbaled side mounted Gun.

 

 

Ise

Edited October 12, 2020 by Isegrim

[Volk.]

Interesting...hadn't thought of the placement height as a factor.

[Fri13]

The KA-50 has superior cannon characteristics compared to Mi-28 (and AH-64 as well) by accuracy and recoil control, allowing long and rapid firing possible with high accuracy.

 

The Mi-28 in state tests was against KA-50 that had 2-3 times better accuracy.

[Fri13]

If the target is outside the Shkval limits, you can't get range information, so a turret wouldn't be a significant advantage.

That's what I was trying to say

 

If you have a laser turned off, you get the altitude radar and target altitude information from KABRIS. You are not accurate as laser, but you are plenty for the below 1000 meter engagements.

[Volk.]

I'm not positive, but I don't think the cannon gets any info from the ABRIS. It does however get angular info from your HMS when you Uncage Shkval. But it still doesn't get ranging, so your bullets fall short. I have read that the bore-sighted cannon is ranged for 1100m, so maybe it's coincidence?

 

 

That said if you look at your tracking gate (the parallel vertical lines) on your Shkval target on the ABRIS, it's only acccurate when you get a ranging lase, and similarly with datalinks you need to laser-range (lock).

[Volk.]

Forgot to mention, under 1km, your shots are starting to fly straight rather than volley/arc a lot more, so yeah, you wouldn't really need much ranging anymore (as long as you didn't have a stored incorrect ranging, e.g. telling the cannon to volley and aim up).

 

 

Interesting on the Mi-28 tests...do you know if the cannon/turret on it was improved since those tests, given that it lost to the Shark many years before the army approved it for production? I.e. it had time to improve the turret design into what one would recognize now as the Mi-28.

Edited October 13, 2020 by Volk.

[Fri13]

I'm not positive, but I don't think the cannon gets any info from the ABRIS. It does however get angular info from your HMS when you Uncage Shkval. But it still doesn't get ranging, so your bullets fall short. I have read that the bore-sighted cannon is ranged for 1100m, so maybe it's coincidence?[/Quote]

 

If you look at the Shkval, you see that the Shkval itself gets range data somewhere each time you designate target. It is not accurate without laser, especially if you are hugging the ground. But take altitude and your triangulation starts working.

 

That said if you look at your tracking gate (the parallel vertical lines) on your Shkval target on the ABRIS, it's only acccurate when you get a ranging lase, and similarly with datalinks you need to laser-range (lock).

Exactly. But KABRIS has own data for altitudes and your attitude.

What it really works with others is pseudo science as it is so unique combo.

 

But as we are talking about aiming cannon by just using HMS, it doesn't make sense to use further than 1bkmv as you can't see targets there reliably, and HMS sync presenting aiming position likely shouldn't be so accurate at all.

 

So the HMS and cannon altitude error data becomes irrelevant as range for it use is so short. And at closer range you shoot using impact points, not by HMS.

 

The HMS precision likely would be around that 1-2 degrees and not like now.

[Fri13]

Interesting on the Mi-28 tests...do you know if the cannon/turret on it was improved since those tests, given that it lost to the Shark many years before the army approved it for production? I.e. it had time to improve the turret design into what one would recognize now as the Mi-28.

 

No information did they change cannon or its turret at all. But I don't believe that would have been done because the benefit was the KA-50 turret position and it benefit to ease in stabilization and aiming precision that underhanded turret can't offer.

 

But you can get better software to compensate via helicopter inputs when in extreme aiming angles etc. But still KA-52 with same cannon is said to be extremely accurate for helicopter.

[3WA]

That, and the designer of the Ka-50 was a huge fan of the American show "Airwolf". That helicopter had side mounted guns, and retractable gear, so there you go.