Attack helicopter

This is my graduation work.
Attack helicopter that is smaller, cheaper and simpler than AH-64, RAH-2 or Mi-28. It's more like AH-1, but with better armor. It's intended for close range combat, in urban and jungle areas. It's not antitank helicopter, it's anti-infantry. It doesn't have complex sighting devices, and its main weapons are 12.7 mm machine gun YakB-12,7 and nonguided missiles.
Takeoff weight is 4500 kg. Maximum speed is 272 km h. Maximum vertical speed is 9.5 m/s. Static ceiling 3 km. Dynamic - 5km. Range - 300 km.

Construction is riveted. Nose compartment structure consist of C-shaped sections and armor plates that works as bearing skin. Middle compartment structure consist of frames and C-shaped sections and bearing skin. And tail boom structure is four ribs and composite bearing skin. Fenestron has composite skin.

Gunship powered with two AI-450TP engines 800 hp each. First engine located right under the main gearbox and intended to protect it from fire from below. Second engine located behind the main gearbox and pretty far from another engine so both of engines cannot be damaged by the same hit.

Great design! Congratulations!

Stash - I admire your work and efforts on your - small, cheap and simple ‘Attack Helicopter’ design!!!!!!!!!!!!!!!!!!!!!!!!!!
It looks as if you have put much thought into it!

Please don’t take this as critisism, but I have a few questions about concept

What are the dimensions of your design????

Incorporate a simplistic rotor-folding mechanism, coupled to this designs light weightiness and compactness, and you could have a very air-transportable combat helicopter for supporting RDF (Rapid Deployment Forces).

Depending on the dimensions (like your point about its similarity of the Bell AH-1 Cobra family), you could fit? in a Lockheed C-130 Hercules / Antonov An-12, which many smaller armed forces around the world use.

What is the AI-450TP engines??
Who makes it? and what other helicopters uses it?

What is the AI-450TP’s high-altitude performance like?
For this could be a cost effective replacement for the likes of the Alouette I / II. Gazelle and Ecureuil series of helicopters in the scout / observation / light attack role.

With your design having one engine located right under the main gearbox and the second engine located behind the main gearbox for the reason of minimizing battle. How easy is engine accessibility for maintenance and replacement by ground crews in the field?

I think that for marketing and versatility purposes though, you should consider some sort of anti-armour capability. Maybe in the form of attachable pod-type sighting/targeting system and a couple of light-weight ATGM or a podded 20mm cannon.
For I think the more versatile you make the design to customer wants and needs, the more likely you are to market it and more importantly sell and manufacture it in any numbers - if any.

How many weapons hardpoints would your design have? – and what weight capability would they each have?

For if your design was cost effective, semi-armoured, have high-altitude performance capability, and easy to maintain and operate, your design could find favor with the military’s of the likes of India, Pakistan, South America and Asia.

For marketing purposes what would you call it?

I look forward to some more CG/drawings/profiles of your design in its full potential combat configuration (camouflage, external weapons etc…..)

With regards
Pioneer

stash said:

Attack helicopter that is smaller, cheaper and simpler than AH-64, RAH-2 or Mi-28. It's more like AH-1, but with better armor. It's intended for close range combat, in urban and jungle areas. It's not antitank helicopter, it's anti-infantry. It doesn't have complex sighting devices, and its main weapons are 12.7 mm machine gun YakB-12,7 and nonguided missiles.

Click to expand...

Beautiful bird - me like ;D

One little nitpick, though. If it's gonna operate against enemy infantry/guerillas/insurgents/whatever in an urban environment, chances are that there's going to be civilians and/or friendly infantry close by. In that environment, you will want the ability to carry and fire precision weapons, lest you want your helicopter to do the enemy's job. Like Pioneer said, at least consider adding additional sensors in pods.

Nice one. I also have a few questions:

1. Where is located the air intake for the engine and what shape does it have?
2. Because of the so thin fuselage, did you consider to place armor plates between the important systems and their backup?
3. If the main mission is anti-infantry, and because its simple equipment, what about to consider single-seater? Two pairs of eyes are better than one, I know, but you save a lot of weight, you will have a smaller side (and front) profile, less cost....

Pioneer said:

What is the AI-450TP engines??
Who makes it? and what other helicopters uses it?

What is the AI-450TP’s high-altitude performance like?
For this could be a cost effective replacement for the likes of the Alouette I / II. Gazelle and Ecureuil series of helicopters in the scout / observation / light attack role.

Click to expand...

The AI-450 is being developed by Ivchenko-Progress. AI-450 turboshaft is rated at 465 shp. It is intended for the Mi-2A and Ka-226. The more powerful (600-800 shp) AI-450-2 is aimed at Kazan's Ansat.

The AI-450TP is a 450-500 shp turboprop derivative.

Thank you for your replies.

Special thanks to Pioneer. It's a great idea to fit this helicopter into An-12/C-130 cargo compartment.

I think I will try to do this in next iteration. Right now it could fit, but without wings, stabilizers, fin, main rotor and it should be tilted. So it will take a day to disassemble and load it on board, and then another day to unload and assemble.

I'll think it over about rotor-folding mechanism. It can be very useful, but that joint can become a real problem.

About engine: I have some information about basic AI-450, and almost nothing about it's 800 hp modification, which I used in design. It's turned out I don't even know the right name. I was told that they doing 800 hp modification called TP and 1000 hp modification called AI-450-2.

to Apophenia: Do you have more information about AI-450-2? Is it 600 hp or 800 hp? Because 600 hp is not good at all. According to calculations, even with 2x800hp it has not so perfect flight characteristics. And with 2x600 it wouldn't even reach 220 km/h.

I was thinking a lot about engine accessibility. And still I overlooked some things. I looked just now and understood that main gearbox cannot be replaced without removing beams above him. And I also screwed up with two beams near the upper engine. That engine and those beams are intersecting. That's because I added those beams just before the graduation presentation.
But actually if dimensions of the 800 hp engine won't change (which I doubt) after some redesigning engine accessibility should be pretty good.

I think that for marketing and versatility purposes though, you should consider some sort of anti-armor capability. Maybe in the form of attachable pod-type sighting/targeting system and a couple of light-weight ATGM or a podded 20mm cannon.
For I think the more versatile you make the design to customer wants and needs, the more likely you are to market it and more importantly sell and manufacture it in any numbers - if any.

Click to expand...

Of course you right about versatility of the design. I wrote that it's anti-infantry because this niche is free. All of specialised attack helicopters are either antitank or reconnaissance. And this one is specialised anti-guerilla. Well, it can be equipped with anti-armor weapons. And there is some place for sighting equipment in the nose. But it shouldn't be too heavy because there can be problems with centering. Armor is pretty heavy. But I don't know how heavy it is. I found information about special steels and about Kevlar, but they are not so heavy in comparison with armored glass. And all information that i found about armored glass was information about armored glass for bank buildings. That glass is 84 kg/m^2. It's capable of resisting bullets up to AKM and M-16.

Back to versatility. I think that armor can be removed and armored glass replaced with ordinary. And then helicopter can be equipped with heavy sighting equipment and can be used the same way AH-64 supposed to be used. I mean attacks from afar with precision weapons.

Okay, next point. Weapon load is 1000 kg on four hardpoints.

Well if it's anti-guerilla, which means, let's face it, human-hunting, I would call it Shere-Khan (you know, form Rudyard Kipling's Mowgli).

This engine is pretty interesting because it has single-stage radial compressor. And air intake's are on the sides of the engine. So they are on the sides of the helicopter. They can be seen on the side view in the drafting which I attached to this reply.

There is a load bearing element between the lower engine and the main gearbox and upper engine. It is also a fire-resisting bulkhead, and maybe it can be armored with Kevlar or something like this.

I didn't consider single-seater. One man cannot handle control and weapons simultaneously. Only two men or one man plus special equipment like Ka-50. And I read that it takes up to 2 hours to programm Ka-50 for a specific conditions (weather, etc.) but this information is not 100% reliable. Besides, it wouldn't make the helicopter any thinner, because it's already 800 mm. Thinner than that can be only unmanned, like "Snark". And it would need a lot of special equipment and complex programs. So I don't think it would make the helicopter any cheaper, but if we consider the cost of gunner's training... Well it's really complex question. Generally I think that if we replace gunner with a computer we should do the same with a pilot. So it's either a two-seater of unmanned.

And about structure of the helicopter. Does anybody know where I can find any information about the structure of modern helicopters? For now I found only this operation manual for Ah-64 and Ch-47 at www.tpub.com

Stash,

According to Ivchenko Progress, the AI-450-2 is rated between 600 and 800 shp. (Ansat would be at the lower end of that range, going by the 630 shp generated by the alternative PW 206Cs.)

http://www.ivchenko-progress.com/welcome.do?id=12&lang=en

I hadn't heard about a 1000 shp variant. Does anybody know the output of the AI-450-MS gas generator in APU use for the An-148?

Your work is very impressive, Stash. Just a thought on rotor folding: since you're aiming at the lower end of the market, so to speak, are folding joints necessary?

Some air forces have issues with partial disassembly for transport (engineer sign-offs at the other end, etc.). But will your market AFs have a problem with simply popping a pin out from four of the five blades to manually stow the blades for air shipment?

I don't think you've taken into account size of weapons and ammunition. Nor have you taken into account safety equipment for the crew nor fuel. There appear to be no engine intakes and where does the electrical system draw its power from? There are no horizontal stabilisers so manoeuvrability will be limited.

I think that a capability of add-on armour as a marketing option would be good - not unlike the French offer with some of their AFV
This way you could still easily transport your 'small, light and simple combat helicopter' design to a given spot/conflict area, then attach the add-on armour as required.
With the modern battlefield being classed as a around the clock / 24-hour thing, and with experiences of many COIN type wars, seeing the insurgents / gorillas predominantly using the night to their advantage, even small armed forces will see a use for passive/active night-vision equipment.
Its a pity, that the likes of your purpose designed and built combat helicopter, could not be given a chance to compete against the non-purpose designed and built types like the OH-58 Kiowa / Kiowa Warrior / Gazelle designs for the Scout/Reconnaissance role - especially if it was able to take far greater punishment and small arms ground fire, than these civilian converted designs


Regards
Pioneer

About rotor folding. I don't think it worth the effort. On bigger helicopters it takes a lot of time end effort to assemble rotor. And it needs special equipment also.
But according to calculations for this helicopter the weight of one blade would be only 38 kg. So several people can easily assemble main rotor if blades were dynamically balanced before and were marked which blade should be placed where. At least I think so. I don't know the process of dynamic balancing very good.

Well I used photo, not drawings, but I wold say that my model of YakB-12,7 is pretty precise, plus-minus 5%. And the dimensions of turret are the same as the dimensions of Emerson TAT-141, which was used at AH-1. Well, more or less, because I didn't find any dimensions so I used the ruler and drawing of AH-1 and got 700 x 400 mm for turret. Wing span is 4m which is bigger than AH-1's 3.23m.

I calculated the volume of fuel that required to get range of 300 km. The whole fuel tank can be fitted under the lower engine between beams.

About place for crew. There wouldn't be much place for people after installing armor, avionics, chairs, life support system, etc. But it's an attack helicopter. It shouldn't be too comfortable. It should be well protected.

About intakes and outtakes. I marked intakes with red in attachment 1 and outtakes with blue. There is no special reason for intakes to be of such complex shape. It's just intersection of two surfaces. Outtake of the lower engine is on the port side only.

Electrical system draws its power from engines, as always actually.

Horizontal stabilizers are there, look again.