marvel sheild C-17x "The Bus"

[Devilfish]

Anyhow, a ramjet does not require Mach 1 speed to operate.

A ramjet has no moving parts.  It compresses the air thru a narrowing cone via high speed  It requires very high speed air passing thru it (usually around Mach 1) for it to start operating.  They generally operate at speeds in excess of Mach 1.  Usually around Mach 2.

[jcf]

I think you are confusing the speed of the air through the ramjet, which
is controlled by internal shape with the speed of the air entering the
mouth. The latter does not need to be Mach 1+.

The first successful ramjet powered flight was in 1939 with two mounted
to a Polikarpov I-15 biplane, and I think you'll agree that notion of an
I-15 going Mach 1 is rather ridiculous.

The Leduc 0.10 was the first aircraft to fly solely on ramjet and it's max
speed was 500mph.

[Devilfish]

I'll have to accept what you are saying. The ramjets I used to work with (Bristol Thors) needed to be pushed to Mach 1 to start working and operated at around Mach 2.

What I do know is that at low speeds they are inefficient, and in VTOL mode completely useless, so in this application, utterly wrong!

[lenny100]

ok base coat of ram paint on dosnt look to bad

[zenrat]

Eh? Do they swivel through 90 deg? 

i dont know, maybe we will see it do that later in the seasons, ive only seen the first 3 episodes so far 

Just watched Episode 7.  All 6 engines point downwards so the thing can hover.  They look to be mounted on a ball joint so they have some degree of sideways directionality.

[Rheged]

The first successful ramjet powered flight was in 1939 with two mounted
to a Polikarpov I-15 biplane, and I think you'll agree that notion of an
I-15 going Mach 1 is rather ridiculous.

A Mach 1 biplane!   GOSH!  I assume that the pilot  was incapable of coherent speech  for some time afterlanding!!

[martinbayer]

A Mach 1 biplane!   GOSH!

Sure, why not:

http://web.mit.edu/newsoffice/2012/supersonic-biplane-0319.html

Martin

[zenrat]

[jcf]

The first successful ramjet powered flight was in 1939 with two mounted
to a Polikarpov I-15 biplane, and I think you'll agree that notion of an
I-15 going Mach 1 is rather ridiculous.

A Mach 1 biplane!   GOSH!  I assume that the pilot  was incapable of coherent speech  for some time afterlanding!!

Umm, it didn't go Mach 1.

[PR19_Kit]

The first successful ramjet powered flight was in 1939 with two mounted
to a Polikarpov I-15 biplane, and I think you'll agree that notion of an
I-15 going Mach 1 is rather ridiculous.

A Mach 1 biplane!   GOSH!  I assume that the pilot  was incapable of coherent speech  for some time afterlanding!!

Umm, it didn't go Mach 1.

Spoil sport. 

[Diamondback]

CAVEAT: I'm only discussing maximum RATED power here, not publicity-stunts like running an engine on a test-stand under triple-redline conditions for bragging-rights like GE did to get the GE90 up to 128k#+. Also, when I discuss "vertical lift weight", that's kind of a "neutral buoyancy"--you need LESS than this limit to get acceleration, and the further below this upper limit you are the better your climb rate.

I'd also assume the SHIELD bird uses highly uprated engines, or more powerful ones.
The stock F117 engine is good for 40,400# normal max throttle (the proposed C-17B would have used a more powerful engine), but other members of the PW2000 family top out at 43K. So if we figure F117's that's 242,400# of vertical lift, while PW2043 airliner version will deliver a vertical lift of 258,000#. A vanilla C-17 EMPTY is 282,500# and grosses out at 585k#. Maybe if we do a total redesign with more composites (and say some experimental new formulas) that will shave a little--5-10% sound like a reasonably conservative estimate?--BUT we have that new rear wing AND two new engines, AND the fuselage structure to take the stresses from the added wing, AND the pivot hardware and structural reinforcements from it. That's a LOT of added weight, even if we do assume that this thing's not going to need anywhere near the 170,900# payload of the standard trash-hauler model... and two bare PW2000s in F117 form add another 14,200# for just the engines in dry condition--nacelles will add even more.

Bottom-line... without upgrading to the next size up in the engine food-chain, I highly doubt this bird's a true VTOL, that'd be an even bigger sack of manure than the VTOL C-17 in Team Knight Rider ~20 years ago, but a VERY Short STOL is plausible.

Vanilla C-17 weights for reference...
Empty airframe: 282,500#
MTOW: 585,000# (maximum ramp weight allows another 1K if you're just rolling across tarmac)
Maximum usable fuel: -A 180,806#, -ER 244,854#
Max payload: -A 170,900#, -ER 164,900#
Interestingly, at heavier payload weights (around 160K cited) the ER LOSES range over the A, defeating its design purpose, while with a 40K light load (hold full of paras) it posts a gain of 1400nm and ferry range (which I generally consider in "Publicity Stunt" territory) gain of around 1490.
Our new engine should ideally fit in an envelope of about 78.5" fan diameter, with a 141.4" flange-to-flange length. The Rolls-Royce RB211 is similar weight-class with minor mod, topping at 60,600# on the -524HT model. That gets us to 363,600#, which is enough to lift the bare airframe but not a lot of fuel or cargo. If we go to GE CF6's, the best we get is 69,800# out of the CF6-80E1A3, which gets us a vertical of 418,800#. Also, we need to remember that as our engines get bigger and more powerful, they get heavier... which is going to eat some of our power gain, and the required structural reinforcement will add even more.

This leaves an interesting discrepancy... difference between MTOW and Empty is 302,500#.

If we Go Big, the GE90 runs at 135" max envelope/128"fan , 287" length. Six stock GE90-115B's at normal operating power is good for a 690,000# vertical lift IF the structures can take it... the bare engines weigh 18,260#--going from 4xF117 to 6xGE90-115B is an empty weight-gain of 81,160# in engine ALONE.

So, let's work the math piece-by-piece... New empty weight in parens
Starting Empty 282500 (282500)
Delete F117's - -28400 (254100) note: does NOT include pylon or nacelle weight
First 4 -115B's - +73040 (327140) note: again, not including pylon, nacelle or structural reinforcement weight
Rear wing:
Rear 2 -115B's - +36520
Of course there's more to be done working the numbers I haven't even touched yet.

Or it could have some other tech... remember how Coulson's Corvette has the full "Hover DeLorean" conversion? (And we KNOW they're playing with some other stuff since they have "heli-carriers" that can't be built with present tech--they make that monster my ex-fighter-jock prof and I designed even with its baked-in anticipation of future tech like fusion reactors and optical cloaking look like a 1700's Ship of the Line by comparison.) Sorry, only caught the pilot... but now thinking this might be a source of ideas for an MC-5 "Special Ops Galaxy" similarly converted into an airborne command-post.

[Captain Canada]

It sure is looking good !

[jcf]

Lola has bugger all to do with the BTTF De Lorean, a flying car has been part of the S.H.I.E.L.D. schtick
in the comic books since the late 1960s.

What the Cap said, any more progress Lenny?

[Diamondback]

I see you can't be content with just throwing up harassing replies to my every post at Beyond The Sprues anymore...

@OP, nice work tackling a challenging and Outside the Box subject.

[Teddz]

any update on this build lenny?

I came across this build while researching images for the Bus for my build... This whole project is my first ever kitbash (using 2 c-17 kits), and also the very first replica prop my new company is making. This one will be a one-off and will probably stay with me (unless someone make a nice offer), but I plan on building another 3 or 4 that will be 'in-flight' like on Coulson's desk.

Unlike your build Lenny, I modeled mine after the aircraft seen on-screen.

First, I started with the engines. The kit supplied were just all wrong. 18 additional pieces of styrene per engine were added to make it look right. There's still some scribing that has to be done to them so they're accurate.



I've cut and stretched the airframe and cargo area...



She's getting fiber optic lights, so I needed to fabricate a PCB for the LED's... the board has 1 green LED with a dimmer, 1 strobe, 2 bright white leds and the 2 for the nav lights. It's all activated by a touch-sensitive on switch with a timer that's going to be in the shape of the SHIELD logo on the base.


12v power comes via the landing gear




The rear wings on the screen aircraft aren't as far back as they're shown on the blueprint. They fit nicely.


cockpit details...


Modification of the longer sponson to match the other side...




Quick dry-fit to see how it is on the 40cm2 x 1cm thick Black Granite tile that will be part of the base. The base will have a 25mm thick plywood backing and be surrounded by either mahogany, walnut or red oak moldings. 


I'm currently in the process of closing up the holes and prepping it for it's first coat of primer... Beyond that, there are still hours of scribing, sanding and finishing before I consider the aircraft ready for paint.