The 5th Generation Fighter challenge [FAR]

[PTGFlyer]

Actually, I guess I'm not doing this. My mom deleted KSP.

[GDJ]

1 minute ago, PTGFlyer said:

Actually, I guess I'm not doing this. My mom deleted KSP.

What!?

[PTGFlyer]

Apparently school and KSP are not supposed to go together, even when I have free time.

[CrisK]

It's not a looker, but I managed to get a flying wing stable at AoA turns of up to 30 degrees, with yaw stability at up to 25% sideslip. Stable at speeds up to Mach 2.8.

Missiles are internal. 4 AMRAAMs and 2 sidewinders. The body will be more compact once BahamutoD releases his new rotating bomb/munitions rack.

 

[Doke]

Oh, I don't know, it has a certain arthropodean beauty. Where on kerbin do you fit those missiles, though?

[CrisK]

1 hour ago, Doke said:

Oh, I don't know, it has a certain arthropodean beauty. Where on kerbin do you fit those missiles, though?

It's hard to tell because of the angle of the screenshot, but the middle piece is a MK2 long cargo bay, and the tanks are radially attached.There's plenty of space in the MK2 bay for 6 missiles. Although sometimes they have a funny habbit of not ejecting, flying within the cargo bay itself, and then blowing up the craft.

[Doke]

That's very impressive, then. I've not had much luck incorporating bays into fighter designs without them being a bit awkward.

[Wjolcz]

I'm really intrigued by the Boeing's flying wing concept and I think I might try to build my own. Just as FGF is a Messerschmit fanboy I'm more of a flying wing guy. Still need to learn a couple of things about FAR though.

E: Also how is the score calculated? The OP seems to be edited and there's no way of telling how to do that.

Edited February 8, 2016 by Veeltch

[CrisK]

Veeltch, I wasn't able to create a model of Boeing's flying wing that could actually fly in KSP. I modelled mine after Northrop Grumman's design for a 6Gen fighter. Here's a link to NG's YouTube video showing off their concept fighter for the Navy's F/A-XX program:

https://www.youtube.com/watch?v=sGzhmVmuSTA

There's a good chance that they'll submit the same design to the Air Force's F-X program.

I reshaped and painted my replica so that it better matches the NG design. It's still stable up to 30 degree AoA turns, and Mach 2.4+. It's actually incredibly stable all-around, but I can't get it to be as maneuverable as a fighter with more control surfaces. NG's design has fairly low wing loading, so I'm not sure if it's possible to increase performance without changing the wing design.

 

Boeing's design looks like this:

PS: Lockheed Martin's design looks like this:

 

Edited February 9, 2016 by CrisK

[CrisK]

I played around with the Boeing design a bit and got it flying. To my surprise, it's supermaneuverable. The design is stable up to an AoA of around 45-50 degrees. In the screenshot it's stable at 52 degrees.

Designing these flying wings has helped me learn how to design better wings. I'll probably update my old fighters at some point.

 

[FourGreenFields]

21 hours ago, Veeltch said:

E: Also how is the score calculated? The OP seems to be edited and there's no way of telling how to do that.

Score is no longer calculated.

 

 

And with all those flying wings about, I feel I should build one next (right after finishing my P 27 "Peregrine"). Wanted to build one anyway.

 

EDIT: I'll just try to dig up how the score might have been calculated:

2 points per 0.1M above Mach 2.0 at "roughly 10km", 2M being minimum speed to pass.

1 point per 0.1M above Mach 1.0 at "roughly 10km" on 1/3 throttle ("Whiplash") or 2/3 throttle (basic jet). 1M minimum to pass.

5 points if it can pull 9G, 6G to pass.

Needs to be able to load a droptank, 1 point per 50 units of fuel in the droptank.

1 point for each hour of endurance while supercruising, except the first hour.

For BD Armoury part: 2 points per weapon, at least one 20mm (or more) cannon; No rearwards facing weapons iIrc.

Thrust to weight ratio bigger than 1 required, but still gives one point.

10 points if supermanoeuvrable.

Edited February 9, 2016 by FourGreenFields

[Pds314]

I just built an unmanned 5th gen drone fighter. The thing is unbelievably aerodynamic at supersonic speeds. Using a pair of B9 F119s, it has a wave drag area of 0.20 m^2 at mach 1. It can supercruise at speeds exceeding Mach 2.2 at sea level, and can exceed Mach 3 at any altitude briefly before the engines overheat and explode using the afterburners. All while carrying an internal payload of 2 AMRAAMs and 6 Sidewinders.

Also, did I mention the Gau-8 visibly poking out the front?

Edited February 10, 2016 by Pds314

[Wjolcz]

Tried to build X-47B. It didn't go well.

I have no clue how to build a modern flying wing. Probably needs more sweep.

[FourGreenFields]

1 hour ago, Veeltch said:

Probably needs more sweep.

Sweep does help with yaw stability, but I don't think that that alone would help.

My guess would be that the X-47 uses artificial stability.

 

May be able to finish the "Peregrine" (which has improved in pretty much every way I think - except maybe slightly lower thrust to weight, but I haven't tested that) tomorrow, and as the X-47B does look somewhat promising, I'll try if I can make one fly after I finished the "Peregrine".

Edited February 11, 2016 by FourGreenFields

[Hodo]

I am amazed by these new flying wings.  I have never been able to get any of my designs to work right.  But I tend to over-engineer most of my craft and want them to do to much. 

 

My current thing is still VTOL SSTOs, and VTOL SSTO fighters.   And getting back to my SSTO lifter projects. 

 

Although the styles I have seen here and the lessons I have learned from messing around with this challenge has improved my SSTOs as a whole so one day I may delve into the world of flying wings. 

[CrisK]

I can't build a successful X-47B replica in KSP either. Northrop Grumman has the benefit of having designed flying wings since the 1940s, plus the best fly by wire software in the world.

At least, that's my excuse!

My advice is to make your flying wings fat using wing parts to craft the body's shape. Flying wings are fat and wide.

I uploaded my Northrop Grumman replica to KerbalX. Other people are welcome to use it as a base.

 

Edited February 12, 2016 by CrisK

[FourGreenFields]

And the "Peregrine" is finished.

 

Craft file on KerbalX

Turns out this thing is still more agile than it needs to be, but I'll just leave it like that for now.

[CrisK]

FourGreenFields, if you swap the nosecone for the shock intake it will resemble a miniaturized Mikoyan MiG-21.

[FourGreenFields]

3 minutes ago, CrisK said:

FourGreenFields, if you swap the nosecone for the shock intake it will resemble a miniaturized Mikoyan MiG-21.

Just DuckDuckGo-ed the MiG-21, and it doesn't exatly look like the "Peregrine" to me (delta wing vs straight wing with extendet leading edge near root for example)

[CrisK]

I played around more with my flying wing designs and they're now both supermaneuverable.

I also managed to successfully refuel a fighter in the air for the first time. My first aerial refueling in KSP!

 

Hodo, any luck with the latest design?

[PTGFlyer]

HOW DID YOU DO THAT

[CrisK]

2 hours ago, PTGFlyer said:

HOW DID YOU DO THAT

The claw! I held the refuelling plane steady with Crzyrndm's Pilot Assistant mod, opened the claw, switched to the jet, and then gently flew into the claw.

[FourGreenFields]

The good news is: I managed to design a X-47B replica that's stable according to the calculations (allthough I had to use quite a bit di- and anhedral)

The bad news is that the calculations might not be that accurate...

Wave drag seems a "tad" low...

 

EDIT: Seems updating FAR fixed it (RIP Kerbalstuff). And made it unstable again.

 

EDIT: After working on it some more it ended up being stable, and with a lower Cd than the "Peregrine". It reaches Mach 1.4 at low alt - with afterburner. Not sure what I'm missing here. (And yes, calculated at Mach 1.4 as well)

Edited February 16, 2016 by FourGreenFields

[PTGFlyer]

22 hours ago, CrisK said:

The claw! I held the refuelling plane steady with Crzyrndm's Pilot Assistant mod, opened the claw, switched to the jet, and then gently flew into the claw.

Huh. Wouldn't you need two claws to keep it steady?

[CrisK]

On 16/02/2016 at 6:22 PM, FourGreenFields said:

The good news is: I managed to design a X-47B replica that's stable according to the calculations (allthough I had to use quite a bit di- and anhedral)

EDIT: After working on it some more it ended up being stable, and with a lower Cd than the "Peregrine". It reaches Mach 1.4 at low alt - with afterburner. Not sure what I'm missing here. (And yes, calculated at Mach 1.4 as well)

FourGreenFields, I think that's pretty good for a flying wing. It's better than the real X-47B. I can't get that wing shape to fly well at all.

PTGFlyer, Pilot Assistant holds the crafts steady. Without Pilot Assistant, the two crafts spin around and violently break apart (I tested this to see what would happen).