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Had this thought today while playing with my brother's LEGO B-Wing:

You ever notice how the craft that have S-Foils are the really high performance, and heavily armed ships?

What if they're the equivalent of the TIE radiator system?

You fly them closed up in cruise mode, since there's not that much waste heat, but open them up to increase cooling when you go into combat..

It's certainly better than "lol +6D Manuverability" when open.

Then it's going to be hard to explain the A-wing with it's huge engines in relation to it's small volume with no S-foils.

Well, actually, I believe ICS had a thing or two for the reason why the ARC-170 opened its S-foils. I think it was to do with radiators.

MKSheppard wrote:Had this thought today while playing with my brother's LEGO B-Wing:

You ever notice how the craft that have S-Foils are the really high performance, and heavily armed ships?

What if they're the equivalent of the TIE radiator system?

You fly them closed up in cruise mode, since there's not that much waste heat, but open them up to increase cooling when you go into combat..

It's certainly better than "lol +6D Manuverability" when open.

This is exactly Saxton's assertion.

If we're talking strictly about OT fighters, then I'd say the S-foils exist merely to give the ships a greater spread of weapon coverage.

Unfortunately, the PT gave us weaponless S-foils on the ARC-170, which begs for yet another explanation.

Yes, I know Curtis explained it, but I wish he hadn't had to.

Well, the S-foils on the ARC-170s were seen deployed exclusively in atmosphere, so they *could* have something to do with maneuverability/repulsors. Although radiators works fine for me.

Galvatron wrote:If we're talking strictly about OT fighters, then I'd say the S-foils exist merely to give the ships a greater spread of weapon coverage.

Unfortunately, the PT gave us weaponless S-foils on the ARC-170, which begs for yet another explanation.

Yes, I know Curtis explained it, but I wish he hadn't had to.

Why do you not like the idea of S-foils as radiators. (genuinely curious) Seems like it gives them a real purpose in my mind.

Lord Relvenous wrote:
Why do you not like the idea of S-foils as radiators. (genuinely curious) Seems like it gives them a real purpose in my mind.

I know you didn't ask me, however, I'm not sold on the idea by virtue that it would make the answer inconsistent with what we see in the movies. Again, the A-wing, which has a significantlly larger engine/hull volume than the X-wing or B-wing doesn't have a S-foil for the radiators. If any of the OT ships would need one, it would be the oft described overpowered, huge engined little interceptor.

Galvatron wrote:Unfortunately, the PT gave us weaponless S-foils on the ARC-170, which begs for yet another explanation.

Yes, I know Curtis explained it, but I wish he hadn't had to.

The ARC-170's S-Foils (and the X-Wing's, too, I guess) wouldn't even work well as extra radiator area, would they? With their geometry, wouldn't most of the radiation from the increased areas just go right back into the wings?

Lord Relvenous wrote:Why do you not like the idea of S-foils as radiators. (genuinely curious) Seems like it gives them a real purpose in my mind.

As opposed to the obvious genuine purpose they had on the X- and B-wings?

I don't like the S-foils on the ARC-170 because they look tacked on. As if the designers felt the ship looked too plain so they had to add some moving parts and some extra wings, so they combined the two. The Eta-2 is an even dumber manifestation of this design philosophy, IMO.

[outburst]Good Christ, the prequels sucked![/outburst]

I agree about the Eta-2, the fold out wings were obviously added to make it look like a predecessor of the TIE fighter. Personally I thought it looked better with the wings folded in... and on the practical side, you lose a lot of lateral visibility with them folded out.

A-Wings also have substantially less volume than X-Wings, much less B-Wings. Lower volume means that waste heat will naturally dissipate more quickly.


OOU, S-Foils are probably merely aesthetics.

Radiator really is a bad explanation, but it's the only one that applies to every S-foil we see. On the other hand, maybe not all S-foils are created equally. Some might be radiators, some might be to deploy weapons, and there might be other reasons we haven't considered.

The A-wing is a bit of a problem. I'd personally explain it as a very hot little fighter, one that gets rid of it's excess heat by simply using it as thrust. Or maybe those engine rings disperse some of it, hell it's probably just a high-maintenance hanger queen.

Napoleon the Clown wrote:A-Wings also have substantially less volume than X-Wings, much less B-Wings. Lower volume means that waste heat will naturally dissipate more quickly.


OOU, S-Foils are probably merely aesthetics.

Less volume mean less surface area. Does not less surface area reduce rate at which heat is dissipated ?

But the surface area to volume ratio gets higher the smaller the object.

A-wings are known to be very maintenance intensive. Given the high performance engines and such, it won't be too surprising that all that electronics and avionics packed into such a small hull would radiate a fair pit of energy. As it is, the compromise was to give the A-wings two lasers vs an X-wing's 4.

Napoleon the Clown wrote:A-Wings also have substantially less volume than X-Wings, much less B-Wings. Lower volume means that waste heat will naturally dissipate more quickly.


OOU, S-Foils are probably merely aesthetics.

A-Wings' engine nozzles more importantly have a much larger area to emit heat relative to their thrust; the TIEs (which possess and require the largest radiators) are the other way around. That explains the conundrum. S-foil craft are in-between.

Anyone care to explain the lack of S-Foils on the part of an E-Wing then? To be fair, not seen in the movies, but another high performance craft with a seemingly lacking ability to radiate excess heat.

If anything I'd say the purpose of the S-Foils aren't so much to do with maneuverability but to allow mounting points for energy weapons. Computer controlled convergence points for S-Foil mounted lasers/ion cannons allow for easier, and more forgivable, targeting for the pilot versus a cluster shot fired from the fuselage.

And for the record, wouldn't "cruise mode" (with S-Foils closed) naturally generate more waste heat? Typically you'd be flying faster, for longer, probably with some equivalent of afterburners on. Now, the real question is... "How DO fighter engines light up without an oxidizing source."

- Asarious

Light up without an oxidizing source? What? This is way beyond basic chemical propulsion.

Alright then, how DO they work?

If you look at it in terms of when the various fighters where built as time goes on they need smaller and less s-foils. The ARC-170 had 6 wings in attack mode, next comes the X-wing which only has 4, then the B-Wing has 2 and finally the A and E Wings have none, though it could be theorised that the E-Wing has radiators in it's fixed wings and as mentioned above. Neither the B nor A Wing needed radiators because of the open design of their engines.

Alot of the "radiator" idea is bad.. if you assume these things work like RL radiatiors. Which they don't. The funky technobabble neutrino radiators work differently (and circumvent some of the limitations of real life radiators - yes its goofy, but noone is saying it isn't.) Radiator size isn't quite as major a danger, for one.

Secondly, increased performance and the "S-foil radiators" are not neccesarily mutually exclusive. If you operate a fighter like an X-wing at higher levels (IE more power through various systems) you will put more strain on the ship as well as generating more waste heat. Having more radiator area to dispose of it more quickly is of course an advantage. IIRC the David West Reynolds books (like the OT: ICS) specified that X-wing weaponry adn engines do operate at the limits of their performance envelopes, spreading the wings probably would help compensate for this (and the engines and weaposn both link to the wings in the X-wing, so having the radiators there does make sense. The same is true to some extent for both the B-wing and the ARC-170.)

Moreover, S-foils having other benefits ("spreading out" the laser cannons and engines on an X-wing, for example) are not neccesairily mutually exclusive with S-foils being radiators. Think of it as being "multi-functional" (The same way you might use low powered laser beams as both a targeting devicee and a weapon, like on a B-wing.)


Fixed-wing ships like the E-wing still have "Wings" even if they don't fold out. Having them fixed as opposed to opening/unfolding is a benefit in some ways (think of the components needed to "open" and close the wings each time) but it obviously also has drawbacks. The Wank performance ot he E-wing, as we know form the DESB, comes from high-tech gadgetry - they probably use higher performance radiators than an X-wing does (which may laso make them more expensive/maintenance intensive.) We do know that the E-wing could only be operated by the R-7 units due to its systems (suggesting the "high end performance" angle, nevermind its wank armaments, engines, and defenses.) but also by the fact that the laser cannon's performance relied on the "synthetic" Tibanna gas it used (which failed, and the weapons conseqeutnyl became less reliable.)

The A-wing is a special case because of several reasons. As IP noted, ,it has larger engines, which is an advantage in terms of disposing of heat. Moreover, the A-wing (At least according to the diagram in the SWTJ I checked) has an exhaust port between the engines facing backwards, so I'm guessing its meant to be able to vent coolant or something to help regulate temperature (or bleed off excess energy.)

Moreover, while the A-wing is high performance with regards to speed and agility, it is also a highyl specialized craft. Its very low mass (which can give it a higher acceleration without neccearily needing a large reactor outpu), but also with smaller and fewer (And probably less powerful) laser cannons than an X-wing, so it probably has lower reactor output overall. It does, it should be noted, have some very large flat surface areas due to its wedgelike shape (as well as the rear mounted fins close to the engines) which can also double as radiator areas, despite its lack of S-foils.

And lastly, as for the Eta Jedi Airspeeder, it is an absurdly tiny fighter with performance traits that mach much larger ships (smaller than the athersprite even.) so radiators are important for that reason alone. I'm sure the fighter grade laser and ion cnanons alone would warrant the radiators even if the engines didn't need them.

Question: and if these s-foil radiators dissipate the heat from the weapons? I'm not an expert, but it seems a possible explanation.

iFrag wrote:Alright then, how DO they work?

Do you want me to invent new physics for you? How they work is less important than that they do and we can quantify their performance. Needless to say, what you're seeing in the heat is just the glowing engine cone and has little to do with the exhaust stream itself (it glows even when the engines are idle or at negligible thrust). The exhaust stream is a relativistic stream of particles somewhat reminiscient of the relativistic jets emiting from black hole accretion disks.

The Xwing s-foils seem to be spread to improve weapon spread and because the seem to move the engines, which would make it more maneuverable at the expense of speed. The Awing and Ewing have only 1 weapon on each side, so they don't need S-foils, unlike the Xwing.