X-4 Enforcer STOVL Assault Transport - a X-COM Skyranger Replica

[Goddess Bhavani]

=== TOP SECRET ===

FOR X-COM EYES ONLY

From: Council of Nations

To: LethalShade

(LethalShade provided the basic planform and hull design for this craft, which I redeveloped to provide original-content-accurate high supersonic dash and vertical landing capability)

Greetings Commander.

In view of increased extra-terrestrial threats requiring rapid transglobal deployment of special forces, the Council of Nations has seen fit to integrate your "Vulcan Mk2" concept into the Skyranger Project.

Javascript is disabled. View full album

In this secure folder you will find up to date flight development photographs of the "X-4 Enforcer" assault transport. Thanks to the latest turboramjet technology it is capable of Mach 3.5 in the stratosphere while retaining a Mach 2+ dash speed at low altitude; allowing an emergency escape sprint unmatched even by alien-augmented fighters at low level. Troop deployment is by infantry fast-rope or ballistic drop of Mechanized Exoskeletal Cybersuits. We believe Dr. Shen's team can fabricate parachute-retarded pallets for deployment of SHIVs and other ground vehicles.

Should you wish to evaluate the craft for your own purpose you may find blueprints for flight simulation attached below.

http://kerbalx.com/pandoraskitten/X-4A-Enforcer-Assault-Transport

Good luck Commander.

=== TOP SECRET ===

FOR X-COM EYES ONLY

Edited August 5, 2015 by pandoras kitten

[LethalShade]

I really love the way you used a cargo bay for the jet engines. Thanks !

(+1 reputation cookie, by the way)

[Goddess Bhavani]

I tried using the Poodle as per your original craft but the ASL ISP was nerfed so bad it generated nearly zero thrust - I thought basic jet engines would work perfectly for lift jets as they can be concealed neatly in Mk2 bays. The resulting wing setup reminded me of the F-35. It's stubby and thick with visible bays near the wing root, but it generates a lot of lift.

I was very surprised at the flight performance of this craft. It mimics 2k Games' intended visuals and craft performance quite perfectly, with the exception of not being able to do a vertical takeoff when fully laden with payload and fuel (that would be very impractical, but for short hauls in the tactical AO, no problems with this craft doing limited range VTOL. I guess in hindsight X-Com could use the Skyranger as a VTOL, but with aerial refuelling before doing supersonic intercontinental hops.

The takeoff roll is really short when fully laden, something that seems to be a trademark as I love STOL-like performance especially from large aircraft - real life C-17s look fantastic doing STOL full power takeoffs!

I recorded enough inflight footage for a showcase video, so I will post and upload when I have time. Starting a new job tomorrow, and I'm glad to have finished the craft for you

[Goddess Bhavani]

Quick update before bed and a new job tomorrow - I didn't know a craft so overweight and stubby could be a joy to throw around the sky like a fighter jet. I need to practise more with the STOVL mode though. I just consider today as the aerodynamic proofing day, and more S/TOVL testing will take place this weekend.

[Sharpy]

As promised in the PM!

No, it's not functional.

First off, the start is plain horrible. It just can't go straight over the runway, turning sharply the moment it crosses 50m/s.

Thankfully, if I spin up the VTOL engines early enough, it needs some 60-70m/s for take-off, which means some desperate maneuvering, struggling not to tear wings off, driving off the runway etc. Actually, the last one is the rescue: once the wheels are off the ground it stops misbehaving immediately.

It climbs to cruise altitude somewhat sluggishly - it got quite a bit of extra weight after all. Three rapiers, four LV-Ns, all fuel tanks full (both LF and OX), six shock cones (heavier but less draggy; need all six for the rapiers), and a big battery and a reaction wheel in the cargo bay. Add a full set of RCS, shielded port instead of the nose cone, and two solar panels from Asteroid Day mod, the only non-stock parts. Can be replaced with standard panels freely. Plus some fuel lines, some struts, heavier wheels... that all adds up. Anyway, 50m/s of vertical speed isn't too bad.

At cruising altitude it gains the 1000m/s in quite reasonable time, then it needs to be carefully pitched up, to 300m/s of climb. If you do this too fast, it will lose wings.

Once air starts running out I switch Rapiers to closed cycle (giving Whips a couple seconds more before they sputter out). That's when I fire the nukes too.

The oxidizer for Rapiers last until some 35km, with apoapsis of about 55km. The rest of the climb is done on Nukes, but by then, with 1800m/s and a long time until apoapsis circularizing is just a formality.

Unfortunately in the orbit it had some 150m/s of dV left. Barely enough to reach an LKO fuel station.

Also: as I burned for the selfies, I brought apoapsis low enough for reentry. I put phys-warp at 4x and one of the cubic octagonal struts by which Nukes are attached exploded to overheating (bug). The crippled plane with some pieces of wing missing failed to perform the reentry, lost all wings on some 32km, and the hull plummeted to death.

So, it's just a proof-of-concept, a prototype, not a functional STOVLSSTO plane. Also, the cargo bay was mostly empty. If there was any cargo, it would need to include extra fuel. (although, due to Pilot Assistant glitching somewhere around 33km up, sending me spinning and wasting some dV, I guess I'd reach the orbit with a bit more fuel.) Nevertheless, if you'd like to play with it, here's the .craft. Keys: 1: whips and rapiers. 2: VTOL engines. 3: Switch Rapiers mode. 4: Nukes. 5: Ladders

Edited August 14, 2015 by Sharpy

[Goddess Bhavani]

I think I'm frankly amazed that it got into space in the first place! I might play with the SSTO craft you provided and work on balance and weight reduction but it's way beyond the original mission specifications. Still, sub-orbital point to point travel might not be out of reach of this design and I do have about 8 oxidizer tanks in the base design to play with, not counting the two in the tanks that may result in having to re-trim the airfoils for balance. So I might try an all-rapier or 4 Whiplash and 1 LVT-30 design since upper atmospheric drag is close to negligible.

The base design can cruise at Mach 2.5 around 15km altitude while consuming just 1.5 units of LF per second. Most of the fuel is used up climbing and accelerating to cruise speed.

Edited August 15, 2015 by pandoras kitten

[Sharpy]

I think giving it two or three aerospikes would easily make it suborbital.without all the mess I made to make it spaceworthy.

[BlueCanary]

Great craft, so much cool for so few parts. It's a shame basic jet's got nerfed so much, imagine the payload capacity of this in 0.90 or even 1.0.2. Still, this is awesome.