Compound Helos

[Hunt3r]

Originally Posted by Expendable Grunt

So forward motion is now entirely because of the back prop thing?

M.

Nope, it's in conjunction with the rotor blades. At speeds where the helo rotor would be stalling, the wings and the rear prop provide most of the thrust. Otherwise, the rear prop provides less thrust and the wings can just be platforms to hold weapons or something.

The only difference is that hovering requires you to pitch up, which is actually advantageous.

The Speedhawk is also planned to be fitted with retractable gear and other things to make it more streamlined.

Anyhow, the wings are a good thing. At least you have something to help with autorotations. Every bit of extra lift counts.

Not to mention, this is a lot cheaper then building a whole new chopper. Yes, you could probably save weight, no, it's not a good idea to test this idea with huge unknowns. Retrofitting choppers is easier then building whole new ones.

[waldo_ii]

Originally Posted by Hunt3r

It's actually better for hovering, better at NOE, and it can hover while pitching up, which means you only have to unmask your radar (referring to the Longbow), and then you can actively track and shoot while presenting a far smaller target.

I don't quite see your point. When tilted down, the radar above the AH-64D would be tilted down with it, and at an awkward angle. What Longbow pilots do now makes more sense. Forgive the crudeness of my diagram.

[Hunt3r]

Originally Posted by waldo_ii

I don't quite see your point. When tilted down, the radar above the AH-64D would be tilted down with it, and at an awkward angle. What Longbow pilots do now makes more sense. Forgive the crudeness of my diagram.

Um, I'm guessing that the radar has a larger scanning range then that, but that's not quite what I meant.

The radar would should be able to look lower btw, it's AG radar.

I meant you can fire AGMs from cover while in a hover to destroy armor. Have the radar up slightly, fire. Instead of unmasking the entire helo, you only unmask the radar.

If you were level and you fired a Hellfire, it'd go straight into the tree.

[[R-DEV]Rhino]

I think its an interesting design, but can't really see it catching on.

I can see the advantages of being able to get to the fight or w/e quicker with this system, but I believe the next step past our conventional choppers in the future will be really a cross between helicopters and VTOL jets merged into one, where you get the insane speeds that jet engines can produce with also the additional element of vertical flight. Of course this may also never catch on due to huge fuel conception to do the hover for jets but we will have to see where the future takes us

[Hunt3r]

Originally Posted by [R-DEV]Rhino

I think its an interesting design, but can't really see it catching on.

I can see the advantages of being able to get to the fight or w/e quicker with this system, but I believe the next step past our conventional choppers in the future will be really a cross between helicopters and VTOL jets merged into one, where you get the insane speeds that jet engines can produce with also the additional element of vertical flight. Of course this may also never catch on due to huge fuel conception to do the hover for jets but we will have to see where the future takes us

That's the thing. This is basically a helo, but faster.

[[R-DEV]Rhino]

Originally Posted by Hunt3r

That's the thing. This is basically a helo, but faster.

ye, but not that much faster to make it worth it from what I can see.

[waldo_ii]

Originally Posted by Hunt3r

Um, I'm guessing that the radar has a larger scanning range then that, but that's not quite what I meant.

The radar would should be able to look lower btw, it's AG radar.

I meant you can fire AGMs from cover while in a hover to destroy armor. Have the radar up slightly, fire. Instead of unmasking the entire helo, you only unmask the radar.

If you were level and you fired a Hellfire, it'd go straight into the tree.

Unless using specifically the AGM-114L, you would encounter this problem. Again, excuse the crudeness of the scale.
(animated, give it a second)

[[R-DEV]DankE_SPB]

Originally Posted by [R-DEV]Rhino

ye, but not that much faster to make it worth it from what I can see.

support on this, applying it to current helis will cost too much for a very little gain
though such design could be perspective, different design bureaus are looking into it or even something more radical, i.e. ka-90 is supposed to take off and gain 400km'h on rotary wing then switch to jet engine and collapse its rotor though its only a concept for now without flying bird

[Hunt3r]

I'd consider this to be a step forward at any rate. A helo that can achieve 250 knots would be a huge step forward for a skycow. That means it's flying at 461 kph, or 287 mph.

The Cheyenne managed 220 knots in level flight before it was canceled. Obviously, a Viper or Longbow with the ducted fan system should be able to hit about the same speed. You'd have a Viper that has longer range, is faster, and can do all of the things your normal helicopter can. A Blackhawk with longer range, higher speed, better performance in hot/high situations, and extremely high commonality with existing Black Hawks is good.

Not to mention, this system would mean more weapons for attack helos.

Also, unlike the Osprey, this can actually autorotate in emergencies. The current system of retrofitting is basically a stepping stone. The Speedhawk should be able to hit 230 kts no problem in the final version. If a brand new design is brought to the table, I wouldn't be surprised to see compound helos be able to hit 300 kts.

Keep in mind that 300 indicated knots is about the maximum speed for commercial jets. A compound helo being able to cruise at 350 mph at sea level would completely destroy the point of the MV-22. As it is, the MV-22 can't be used like an Apache, has no suitable weapons to equip it with, and is more complicated then it needs to be.

A compound helo variant of a Viper would be more then capable of escorting an MV-22, and also fulfilling it's original requirements, being a helo that flies a more conventional NOE, but capable of holding more weapons.

Also, the gain of retrofitting it to a helo, and modifying the design to be more streamlined will be well worth it. You would go from a cruise speed of 120 knots to 220 knots. A gain of 120 mph is quite large. And once you're in the combat zone and the speed isn't required, you still are a normal helo, capable of doing all the same things with similar capability.

[McBumLuv]

Key words... Vector thrust.

As computing capabilities on a whole improves, the ability to get different vector thrust in any form is increased. I mean, the swept back wing design wasn't possible until recently due to the inability to properly take off and land without modern computing, AFAIK.

While the chance to "upgrade" all these helicopters to this type of flight design may prove to be largely cost ineffective, I'm sure future aircraft design will be including more and more vector thrusting in different applications, rather than having all your power pointed in a static direction.